Biology 1308 - Final Exam Review
Cold-blooded reptiles are prone to losing heat when they aren't absorbing it from the sun. As they lose heat, they also lose energy, which causes them to move more slowly. This energy loss increases their vulnerability to predators. In order to regain energy, reptiles have to absorb it from the environment. For lizards, this usually means sitting out in the open on a rock that has been warmed by the sun. This
"basking" behavior also increases their chances of becoming prey.
The prefix proto- means
"first." A protosome's mouth forms from the first opening, the blastospore.
The prefix deutero- means
"second." A deuterostome's mouth forms from a second opening.
Crustaceans
(crabs, crayfish, lobsters, shrimp, and barnacles) -possess 2 pairs of antennae -have compound eyes -respire by gills
Phylum Chordata (invertebrates)
(humans, birds, apes, mammals, reptiles) - all chordates have deuterostome development (characteristic of the echinoderms) - 4 distinctive features possessed by all chordates during some stageoftheir lives 1. dorsal nerve cord 2. notochord 3. pharyngeal gill slits 4. post-anal tail
Alveolates
(parasites, predators, and phytoplankton) single-celled organisms that have distinctive, small cavities beneath the surface of their cells -subgroup: dinoflagellates Dinoflagellates: swim by 2 whip-like flagella -photosynthetic
Arachnids
(spiders, ticks) -lack antennae -have 8 walking legs -most are carnivorous -some such as spiders and scorpions inject paralyzing venom into prey -they breathe by using thracheae, lungs, or both -some have simple image-forming eyes, each with single lengs -abdominal glands produce protein threads (silk) that're used to weave webs
To remember the difference between the three germ layers and the tissues they develop into, remember these things:
- Endo- means "inside" or "within." Cells of the endoderm develop into the inner linings of the digestive tract and respiratory system. - Ecto- means "outside" or "outer." Cells of the ectoderm form the skin, nerves, and sense organs (like ears and eyes). - Meso- means "middle." Cells of the mesoderm form the muscles.
Primates are mammalian chordates with the following characteristics:
- They have relatively long fingers and toes with nails instead of claws. - They have arms that can rotate about the shoulder joints and a strong clavicle, or collar bone. - They have forward-facing eyes and, therefore, binocular vision. - They have a well-developed cerebrum.
cientists classify animals into the nine phyla based on their adult body plan and embryological development. Features of an animal body plan include:
- levels of organization (specialized cells, tissues, organs, organ systems) - body symmetry (bilateral or radial) differentiation of germ layers - formation of body cavities (coelom, pseudocoelom, acoelom) - patterns of embryological development (protostome or deuterostome) segmentation - cephalization (does it have a head?) limb formation
Kingdom animalia contains a great diversity of organisms. However, all animals share some basic characteristics that distinguish them from organisms in other kingdoms:
-Animals are multicellular and all of their cells have a nucleus. -Animal cells are surrounded by a cell membrane and do not have cell walls. -Animals are composed of specialized cells that form tissues, organs, and organ systems. -Typically, animals reproduce sexually. -Animals are heterotrophs, meaning they must obtain energy by ingesting food. -All animals, in one or all stages of their lifetime, are capable of motion. -Because of their nervous system and muscle tissue, animals are able to react to stimuli encountered in their environment.
Bacteria -Cell walls -Ribosome -Cell membrane -Plasmids -Large circular DNA molecule -Cytoplasm
-Microscopic single-celled organisms -They have a cell wall, cell membrane, cytoplasm and plasmids. -They lack a nucleus but contain a circular chromosome of DNA. -Some bacteria can carry out photosynthesis but most feed off other living or dead organisms. Examples: Lactobacillus bulgaricus (used in the production of yoghurt from milk) and Pneumococcus (pathogen causing pneumonia).
Protoctists
-Microscopic single-celled organisms. -Some, like Amoeba, that live in pond water, have features like an animal cell. -Some like Chlorella, have chloroplasts and are more like plants. -A pathogenic example is Plasmodium, responsible for causing malaria.
Plant
-Multicellular organism -Cells contain chloroplasts which able to carry out photosynthesis. -Cells have cellulose cell walls. -They store carbohydrates as starch or sucrose. Examples: flowering plants such as a cereal (maize) and a herbaceous legume (peas and beans).
Animals
-Multicellular organism -No cell walls -Have nervous coordination that are able to move from one place to another. -Store carbohydrates as glycogen. Examples: mammals (humans) and insects.
Scientists classify animals into nine phyla:
-Porifera: This phylum contains the simplest animals, the sponges. Sponges contain some specialized cells, but no other features of a more complex body plan. - Cnidaria: This phylum includes the simplest animals with symmetry. Cnidarians are radially symmetric and have two germ layers. Jellyfishes, sea fans, and sea anemones are members of phylum Cnidaria. -Arthropoda: This phylum includes bilaterally symmetric, segmented animals with exoskeletons and jointed appendages, such as insects, spiders, and scorpions. -Nematoda: This phylum contains nonsegmented worms with pseudocoeloms. -Platyhelminthes: This phylum contains the simplest animals with three germ layers. These flattened worms are bilaterally symmetrical, nonsegmented, and they have no coelom. -Annelida: This phylum includes segmented worms with a true coelom, such as earthworms, leeches, and some marine worms. -Mollusca: This phylum includes soft-bodied animals that have an internal or external shell, such as snails, slugs, and clams. -Echinodermata: This phylum contains radially symmetrical, deuterostomes with spiny skin and an internal skeleton, such as sea stars, sea urchins, and sand dollars. Because they are deuterostomes, echinoderms are considered to be closer relatives to chordates than the other invertebrates. -Chordata: This phylum includes animals with a dorsal nerve cord, a notochord, pharyngeal pouches, and a post-anal tail at some point in their development. Lancelets and tunicates are invertebrate chordates, but most other chordates are vertebrates. Examples of vertebrate chordates include fishes, amphibians, reptiles, birds, and mammals.
Viruses
-These are small particles, smaller than bacteria. -They are parasitic and can reproduce only inside living cells. -They infect every type of living organism. -They have a wide variety of shapes and sizes. -They have no cellular structure but have a protein coat and contain one type of nucleic acid, either DNA or RNA. Examples: the tobacco mosaic virus, the influenza virus (causes 'flu') and the HIV virus (causes AIDS).
Funqi -Cytoplasm -Ribosome -Mitochondrion -Nucleus -Cell wall -Cell membrane
-Usually organised into a mycelium made from thread-like structures called hyphae, which contain many nuclei Some examples are single-celled -Have cell walls which made from chitin. -They feed by extracellular secretion of digestive enzymes onto food material and absorption of the organic products (saprotrophic nutrition) -Store carbohydrates as glycogen. Examples: Mucor (hyphal example) and yeast (single cell example). Fungi cannot carry out photosynthesis. Instead they use saprotrophic nutrition. They secrete enzymes onto their food so that digestion happens outside the fungal cells. They then absorb the digested organic products.
Body cavities (bilateral)
-act as a skeleton, providing support for the body and a framework against which muscles can act -form a protective buffer between internal organs and the outside world -allow organs to move independently of the body wall
several adaptations have allowed vertebrates to successfully invade most habitats
-development of paired appendages (fins, legs, wings) helped to stabilize movement -increased size and complexity of the brain and sensory structures allowed these animals to perceive their environment in detail and to respond in a variety of ways
An animal body plan refers to the organization of particular body structures in an animal. There are eight features of animal body plans:
-level of organization -body symmetry -differentiation of germ layers -formation of a body cavity -patterns of embryonic development -segmentation -cephalization -limb formation
Flatworms (Platyhelminthes)
-may be parasitic/ free-living -bilaterally symmetrical -some are parasites (organisms that live in/on the body of another organism which is harmed as a result of the relationship) -can reproduce both sexually and asexually -free-living species can reproduce by cinching themselves around the middle until they separate into halves, each which generates its missing parts -most are hermaphroditic, which allows them to reproduce through self-fertilization -they have organs but lack respiratory and circulatory systems -most have sense organs (eye spots that detect light and dark) -they have cells that respond to chemical and tactile stimuli -nervous system consist of clusters of nerve cells called ganglia, in the head, forming a simple brain -they have paired nerve cords that extend the length of the body and conduct nerve signals to and from the ganglia -body plan is accompanied by cephalization, where sense organs are concentrated in the anterior portion of the body -this enhances an animal's ability to respond appropriately to any stimuli that it encounters *some are harmful to humans Tapeworms can infect people who eat improperly cooked meats infected by the worms - its larvae form encapsulated resting structures, called cysts, in the muscles of these animals - cysts hatch in the human digestive tract and young worms attach themselves to lining of intestine - can grow to over 20ft Liver and Blookd Flukes (schistosoma) cause disease schistosomiasis which affects 200mill people worldwide
Post-anal tail
-posterior extension, runs past anus -post-anal tail is lost during early stage of development
exoskeleton
-protects against predators -provides rigid attachment sites for muscles, but are thin and flexible at joints to increase the range of movement of the appendages -provides a watertight covering -exoskeleton must be (molted) shed and replaced with a larger one -molting uses energy and leaves animal temporarily vulnerable to predators -exoskeleton is heavy and weight increases exponentially as animal grows
Genetic info has fostered a revision of protist classificiation
-some species had been previously grouped on the basis of phsyical similarity actually belong to independent evolutionary lineages -some protist groups sharing little resemblance have been revealed to share a common ancestor and classified together *past classifications of protists grouped species according to their mode of nutrition -they didn't accurately reflect our current understanding of phylogeny -photosynthetic protists are collectively known as algae and single-celled, nonphotosynthetic protists are called protozoa
Notochord
-stiff but flexible rod -between digestive tract & nerve cord -present during early stages of development & disappears with skeleton
Sponges
-the only animals that retained the ancestral lack of tissues -individual cell act independently and aren't organized as tissues -this unique feature suggests the split between sponges and the evolutionary branch leading to all other animal phyla must've occurred very early in animal history
Sponges have 3 major cell types, each with a specialized role
1. Flattened epithelial cells cover the animal's outer body surfaces. -some epithelial cells are modified into pore cells, which surround pores, controlling their size and regulating water entry 2. Collar cells- flagellated cells that maintain water flow through the sponge 3. Amoeboid cells- motile cells that digest and distribute nutrients, produce reproductive cells, and secrete skeletal projections called spicules
3 Classes of Mollusks
1. Gastropods 2. Bivalves 3. Cephalopods
All chordates exhibit these four characteristics at some point during their life cycle:
1. They have a dorsal, hollow nerve cord. 2. They have a notochord. 3. They have a tail that extends past the anus. 4. They have gill slits.
To survive as an individual, all animals must maintain homeostasis by doing the following:
1. gathering and responding to information in their environment 2. obtaining and distributing oxygen and nutrients throughout their body 3. collecting and eliminating wastes from their body
Approximately when did the first true mammals appear?
220 million years ago
About how many species of primates are there?
230
The anthropoids spilt into two groups about
45 million years ago when the continents moved apart. The New World monkeys live in Central and South America and have prehensile tails that can help them grip tree branches. The other group of anthropoids includes the Old World monkeys and the great apes. Like the New World monkeys, the Old World monkeys also live in trees, but they do not have a prehensile tail. The great apes, or hominoids, include gibbons, orangutans, gorillas, chimpanzees, and humans.
Based on molecular clock data, scientists currently believe that humans and chimpanzees last shared a common ancestor about
5 to 10 million years ago. In 2002, a team of scientists uncovered a skull that is perhaps the oldest hominine found so far. The skull belongs to the genus Sahelanthropus and has been determined to be about 7 million years old. Scientists are relatively sure that Sahelanthropus is a hominine and a relative of modern humans. Whether Sahelanthropus turns out to be an ancestor of modern humans or not, however, is still in question.
What is a blastula?
A blastula is hollow ball of cells that results from mitosis within the embryo.
How did the development of a larger cerebrum help primates survive in their environment?
A larger cerebrum allowed primates to process what they saw, heard, and touched. This would allow hem to escape predators and discover new ways to get food.
What is a notochord?
A notochord is a flexible rod-like support that lies just below the nerve chord.
What is a notochord? In most chordates, when is the notochord present?
A notochord is an internal supporting rod of connective tissue. Most chordates have a notochord only when they are embryos.
Along with a notochord, what is a second major characteristic of chordates?
A second characteristic of chordates is that they all have a tubular nerve chord that runs along the dorsal side of their bodies.
What is a third characteristic of chordates? When in their development do humans possess this characteristic?
A third characteristic of chordates is that they all have paired gill slits. Humans have gill slits in the embryonic stage.
What is the definition of a vertebrate?
A vertebrate is any animal that has a backbone, or a spinal column.
When do scientists believe the first primates appeared?
About 60 to 70 million years ago.
About how many of Earth's animal species are invertebrates?
About 95% of the animal species on earth are invertebrates.
According to the fossil record, how long has life existed on Earth?
According tot the fossil record, life has existed on Earth for 3.5 billion years.
Currently, most scientists believe that the Homo genus originated in
Africa and spread out from there. There also seems to be a consensus that the first Homo species left Africa about 1.8 million years ago. Which species that was, however, remains uncertain.
What characteristics do all animals share?
All animals are multi-cellular. The cells of all animals have a nucleus and they do not have a cell wall. All animals eat food.
Which of the following is not a primate?
All are primates. (human, gorilla, and baboon.)
What characteristics do all chordates share?
All chordates have a notochord, paired pharyngeal pouches (or gill slits), or post-anal tail, and a dorsal nerve cord at some time during their life cycles.
Which of the following describes the major types of animals?
All chordates share a common ancestor; but there is no common ancestor of all invertebrates.
Which of the following is true about primates?
All primates except for humans have prehensile feet.
What phylum do all vertebrates belong to?
All vertebrates belong to the phylum Chordata.
What is an invertebrate?
An invertebrate is an animal that does not have a backbone.
Characteristics that distinguish animals from other taxonomic groups
Animals are: eukaryotes multicellular lack cell wall obtain energy by consuming other organisms reproduce sexually motile at some point in their life cycle most are able to respond rapidly to external stimuli (nervous system)
Worms with segmented bodies and a true coelom that is lined with tissue derived from mesoderm belong in phylum
Annelida
Insects are members of the phylum
Arthropoda. Spiders, centipedes, and crustaceans are members of this phylum, too. Arthropods are bilaterally symmetrical, segmented animals that show cephalization.
Nonhuman primates have never been native to
Australia
How did the development of binocular, or stereoscopic, vision help primates survive in their environment?
Binocular vision gave early primates depth perception, which made it easier to move through trees to find food and avoid predators.
Most bilateral animals have body cavities
Body cavities- fluid-filled cavities between the digestive tube and the outer body wall -gut and body wall are separated by fluid-filled space, creating a "tube-within-a-tube" body plan -radially symmetric animals don't have body cavities
Which fishes are considered the most advanced?
Bony fish are (Osteichthyes) are considered the most advanced fish.
Fossil evidence has shown that animals appeared on Earth well before the
Cambrian Explosion, which occurred around 530 million years ago. Based on fossil and molecular evidence, scientists have constructed cladograms for invertebrates and chordates that represent the current thought about the evolutionary relationships among the invertebrate and chordate groups. These cladograms also show at which point important features evolved.
What type of body cavity do chordates have?
Chordates have a coelom.
What type of body symmetry do chordates have?
Chordates have bilateral body symmetry.
What advantages did multicellularity have for the first animals?
Collections of cells could access more oxygen and collect more food. They could also control their internal environment and be more efficient by working as a team.
Why do some dolphins wear sponges as "gloves" to cover their rostra?
Dolphins that live in areas of the ocean that have a harder substrate use the sponges to protect their rostra from being injured when digging up fish.
What happens to the notochord in vertebrates?
During the embryonic stage, the notochord in a vertebrate is replaced by a column of bone or cartilage. This becomes the animals' backbone.
Major Groups of Protists
EXCAVATES - Diplomonads - Swim with flagella - Heterotrophic - lack mitchondria - Genus Giardia EUGLENOZOANS- Euglenids/Kinetoplastids - flagella - heterotrophic - inhabit soil/water, have eyespot - Genus Euglena/Trypanosoma STAMENOPILES- water molds/diatoms/brown algae - flagella/glide/nonmotile - heterotrophic/photosythetic - filamentous, silica shells, seaweeds of temperate oceans - Plasmopara, Navicula, Macrocystis ALVEOLATES- Dinoflagellates - swim with 2 flagella - photosynthetic - many bioluminescent - Genus Gonyaulax
Non-Photosynthetic Protists
Euglenozoans Group-Kinetoplastids: have multiple copies of DNA ~arrangement of DNA is diff. than prokaryotes -can cause human disease -genus Trypanosoma (african sleeping sickness) - transmitted to humans by infected tsetse flies Group-Stramenopiles-distinctive flagella ~all members have fine, hair-like projections on flagella Group-Water molds(oomycetes)- have important impacts on humans -tufts- superficially similar to structures produced by some fungi, resembles stem -live in water/damp soil -decomposers -1 species causes disease in grapes (downy mildew), another causes disease of potatoes (late blight) EXCAVATES-lack mitochondria - they have feeding groove subgroups - diplomonads & parabasalids, anaerobes Diplomonads- 2 nuclei, mutliple flagella genus - Giardia - pose health risk in U.S. (parasitic) ~cysts of this diplomonad are released in feces of infected humans, dogs, -single gram of feces = 300 mill. cysts -when cyst deposited into water, human drink, infect, giardia consumed Parabasalids- anaerobic, flagellated, parabasal body -usually live inside other organisms -parabasalids in gut of termites digest wood the termites eat Trichomonas vaginalis - causes STI ALVEOLATES - single-celled, distinct cavaties subgroup - apicomplexans -parasitic, lack flagella -can't move on their own -CAN LIVE INSIDE THE CELL of their host -live inside body of host -have infectious spores -complex life cycle -Genus Plasmodium - malaria - spends part of life cycle in body of female Anopheles mosquito - protists develop in human liver Subgroup - Ciliates - most complex of alveolates -specialized organelles -have short hair-like growth on their body Genus- parameciumis - respond to environment, move quickly -single cell organism behaves like it has nervous system, can avoid danger Genus - didiniumis - an accomplished predatory ciliate RHIZARIANS- have elaborate shells subgroup - foraminiferans - shell has calcium carbonate -dead fora. accumulate on ocean bottom and become limestone deposits subgroup - radiolarians- shells made of glass-like silica -shells accumulate to form sediment layers AMOEBOZOANS- no shells, pseudopods -move by extension finger Subgroup - amoebas - fresh water , some predatory/parasitic ~parasitic- amoebic dysentry - severe diarrhea Subgroup - slime molds - decomposers, live on forest floor ~physical form of slime molds seem to blur the boundary between colony of separate individuals and a single, multicellular individual 1. mobile feeding stage 2. stationary reproductive sage -2 main types - decomposers release nutrients -acellular slime mods - plasmoidal - massive cytoplasm with multiple nuclei which aren't enclosed in cells -cellular slime molds- live as independent cells - aggregate into pseudoplasmodium, mass of individual cells when under stress - food scarce
What five classes of animals belong to phylum Chordata?
Fish, amphibians, reptiles, birds, mammals all belong to the phylum Chordata.
What are the five classes of vertebrates?
Fish, amphibians, reptiles, birds, mammals are the five classes of vertebrates.
How long have sponges had the same basic body structure?
For around 600 million years
What type of fish are hagfish and lampreys?
Hagfish and lampreys are jawless fish.
The oldest known member of the Homo genus found so far is
Homo habilis, which means "handy man." This species was given this name because one specimen was found with tools made of stone and bone. Homo habilis lived about 2.5 to 1.6 million years ago. The earliest fossil evidence of Homo sapiens places the emergence of modern humans at about 200,000 years ago.
What function does the shape of the star-nosed moles's nose serve?
It helps the mole find food.
Vertebrate Groups
Lampreys Cartilaginous fishes Ray-finned fishes Coelacanths Lungfishes Amphibians Reptiles Mammals
What common chordate characteristics do lancelets have? What features do they lack?
Lancelets have a notochord. They are bilaterally symmetrical and segmented. They lack common chordate characteristics like jaws, an anterior brain with associated sensory organs, and paired fins.
Sponges have kept the same body structure for millions of years. So why haven't they evolved?
Mainly because they don't need to. Remember that evolution is driven by the need to adapt to an environment. Sponges are very well adapted to their aquatic life and, therefore, they have had no need to significantly change for millions of years.
The other two phyla that include non-chordate invertebrates are
Mollusca and Echinodermata.
Anatomical Features that Mark Branching Points on the Animal Evolutionary Tree
Most animal phyla that currently populate Earth were present by the Cambrian period 500 mill. years ago Systematists search for clues about the evolutionary history of animals by examining features of: -anatomy -embryological development -DNA sequences
What group makes up most of the invertebrate species?
Most invertebrate species are insects or other arthropods.
Scientists split primates into two large groups:
One group includes lemurs and lorises while the other group includes tarsiers and anthropoids. Anthropoids are humanlike primates. This group includes monkeys, great apes, and humans.
Scientists split primates into two groups:
One group, which includes the lemurs and lorises, are small, nocturnal primates with large eyes. The other group contains tarsiers and anthropoids. Anthropoids are humanlike primates.
How do these adaptations help primates survive in their environments?
Opposable thumbs allow primates to grasp objects, such as tree limbs or tools. Forward-facing eyes allow for depth perception. High Intelligence allows for more complex problem solving.
Bilateral Symmetry
Organisms with bilateral symmetry have two sides that are mirror images of each other. Animals with definite anterior and posterior ends exhibit bilateral symmetry. Ex: a butterfly.
Radial Symmetry
Organisms with radial symmetry have body parts that extend out from a central point. The starfish has a body with radial symmetry.
How was the production of oxygen on the primitive Earth important to the formation of animals?
Oxygen is necessary for the formation of collagen, a protein found only in animals.
Mitochondria
POWERHOUSE OF THE CELL!!!!!!!!!!!!!!!
Cnidarians
Phlyum Cnidaria (jelly fish, sea anemones, corals, and hydrozoans) -have no tissues and 2 body types -nerve cells organized into tissue called nerve net, which branches through the body and controls the contractile tissue to bringabout movement and feeding behavior -they come in a variety of forms, all of which are variations on 2 basic body plans: the polyp and medusa -reproduction varies among diff. types of cnidarians -species may have both polyp and medusa stages -have stinging cells -capable of both sexual and asexual reproduction
One of the earliest chordates scientists have found in the fossil record so far is called
Pikaia. Like tunicates, scientists believe Pikaia was an invertebrate. They also believe it had a notochord and muscle pairs lining its sides, characteristics it shares with today's chordates. Pikaia lived during the mid-Cambrian period—about 510 to 500 million years ago.
Animal Phylums
Porifera (sponges) Cnidaria (jelly fish) Ctenophora (comb jellies) Nematoda (round worms) Arthropoda (insects, arachnids, crabs) Platyhelminthes (flatworms) Annelida (segmented worms) Mollusca (clams, snails, squid) Echinodermata (star fish) Chordata (lancelets, vertebrates)
What are three of the characteristics primates share?
Primates have opposable thumbs, forward-facing eyes, and high-intelligence.
Bilateral organisms develop in 2 ways
Protostome development -body cavity forms within the space between the body wall and digestive cavity (nematodes, arthropods, annelids, and mollusks) Deuterostome development -body cavity forms as an outgrowth of the digestive cavity (echinoderms and chordates)
Nonphotosynthetic protists are collectively known as
Protozoa
Distinction between radial and bilateral symmetry in animals is closely tied to a corresponding difference in the number of tissue layers, called germ layers
Radially symmetrical animals have 2 embryonic tissue layers Bilaterally symmetrical animals have 3 tissue layers Germ layers arise during embryonic development
When do scientists believe the first modern humans appeared? What other Homo species was alive at that time?
Scientists believe modern humans first appeared about 150,000 years ago. Homo neanderthalensis also lived at that time.
What groups do scientists think share a common evolutionary origin with chordates?
Scientists believe that echinoderms, hemichordates, and chordates share a common evolutionary origin.
What environmental conditions do scientists believe may have contributed to the development of bipedalism, or walking on two feet?
Scientists believe that the climate may have cooled about 10 million years ago, leading to the development of open grassy savannahs where there was once tropical jungle. As hominids adapted to this more open environment, scientists believe they began walking on two feet.
When do scientists believe that the lineage that led to humans split from the linage that led to great apes?
Scientists believe that the lineage that led to humans split from the lineage that led to great apes about 6 million years ago.
Which of the following occurred before the Cambrian Explosion?
Some animals demonstrated signs of segmentation and bilateral symmetry.
Explain how an animal's body is organized and how this contributes to an animal's complexity.
Specialized cells are grouped together into tissues. Tissues make up complex organs. Organs work together in organ systems to carry out complex tasks.
What is a blastopore? What does the blastopore become?
The blastophore is an opening in the blastula. The blastospore will develop into the animal's digestive tract.
Describe the adaptation of the platypus that helps it forage successfully for food.
The duck-billed platypus has a bill that can sense electrical currents emitted by living organisms, which give away its prey's location.
Describe the first living organisms that appeared on Earth.
The first living organisms that appeared on Earth were single-celled organisms without a nucleus, much like bacteria. They're single-celled eukaryotes that sometimes grew in colonies.
What does fossil evidence indicate about about the order in which these three vertebrates evolved: a bony fish with a jaw, a jawless fish, and a fish with leg-like fins.
The fish with leg-like fins was the last to evolve.
What vertebrate class is the most successful?
The fishes are the most successful vertebrate class.
List the 8 invertebrate phyla.
The main invertebrate phyla are Porifera (sponges), Cnidaria, Echinodermata, Platyhelminthes (flatworms), Nematoda (roundworms), Annelida (segmented worms), Mollusca (mollusks), and Arthropoda.
Predict which types of tissues arise from each germ layer.
The mesoderm forms muscle tissue. The ectoderm forms skin and nervous tissue, and the endoderm forms the digestive and respiratory tissue.
Describe the sequence in which scientists believe life evolved.
The most primitive living things grew in the water millions of years ago. Gradually, organisms developed the ability to make food using photosynthesis. Over millions of years, more complicated organisms developed, including protists, fungi, plants, and animals.
How does the manner in which the platypus swim help it find food?
The platypus swings its bill from side to side to pick up electrical currents from prey organisms that may be under the substrate. It stores the food in its cheek pouches until it surfaces.
What are the vertebrate classes? Give an example of an animal that belongs to each class.
The seven vertebrate classes are: Agnatha (hagfish), Chondrichthyes (sharks), Osteichthyes (bony fish), Amphibia (frogs), Reptilia (turtles), Aves (birds, and Mammalia (humans).
What adaptation helps this snake avoid being eaten by birds of prey?
The sidewinder has evolved a coloration that helps it blend in with the sand, making it more difficult for birds of prey to spot it.
What adaptation allows the sidewinder snake move through the hot sand without burning its scales?
The sidewinder moves sideways through the sand while maintaining two points of contact between its body and the sand. This holds the sand in place and helps the snake propel itself forward very quickly and avoid being burned.
To remember the difference between radial symmetry and bilateral symmetry, remember these things:
The term radial = radiate - body parts of animals with radial symmetry radiate out from a central point, like spokes on a wheel. The prefix bi- means "two" (bicycle = two wheels) - the two sides of an animal with bilateral symmetry are mirror images for each other.
What are the three germ layers called?
The three germ layers are called ectoderm, mesoderm, endoderm.
How many phyla include invertebrate chordates?
There are two phyla that include invertebrate chordates.
White acorn barnacles (top) and California mussels (bottom) have some things in common, too.
They are both stationary as adults. They feed, get oxygen, remove waste, and reproduce by opening their shells and letting water in and out. But, surprisingly, they don't belong to the same phylum.
All animals have certain characteristics:
They are multicellular and their cells have a nucleus. So animals are eukaryotes. Unlike plants, animals cannot make their own food. They must get the nutrients they need by eating other organisms. Therefore, all animals are heterotrophic.
Which statement is true of homo sapiens?
They have been Earth's only hominine for the last 24,000 years.
One of the earliest major innovations in animal evolution was the appearance of tissues
Tissues- groups of similar cells integrated into a functional unit bodies of almost all animals include tissues except sponges
The article also mentions two groups of invertebrates that are part of the phylum Chordata. What are the names of these groups?
Tunicates and lancelets are two groups of invertebrates that are members of the phylum Chordata.
What other features do vertebrates share?
Vertebrates also have a brain that is encased in a skull and two pairs of appendages (arms, legs, fins, or wings, for example.)
What are the general characteristics of vertebrates?
Vertebrates are relatively large. They have specialized body parts and bilateral symmetry. And they are widely distributed over the Earth.
How are the bodies of vertebrates similar to one another?
Vertebrates have an internal skeleton made up of bone and cartilage. They have a spinal column and a brain enclosed in a skull. They have a closed circulatory system and a heart with two, three, four chambers. Most vertebrates also have two pairs of appendages that may be fins, limbs, or wings depending on what type of animal it is.
Do most chordates exhibit cephalization? How do you know?
Yes, most chordates exhibit cephalization because they have an anterior enlargement of the nerve chord, or brain, that's associated with specialized sensory organs.
Secondary Structure
a "substructure" within a protein, resulting from hydrogen bonds between parts of the peptide backbone
Acoelomate animals do not have
a cavity between their digestive tract and the body wall.
Prokaryote
a cell that lacks a nucleus and other membrane-bounded organelles; bacteria and archaea
Solvent
a chemical in which other substances dissolve, forming a solution
Solutes
a chemical that dissolves in a solvent, forming a solution
Peptide Bond
a covalent bond between adjacent amino acids; results from dehydration synthesis
Non-polar Covalent Bond
a covalent bond in which atoms share electrons equally
Polar Covalent Bond
a covalent bond in which electrons are attracted more to one atom's nucleus than to the other
Species
a distinct type of organism
Unsaturated
a fatty acid with at least one double bond between carbon atoms
Saturated
a fatty acid with single bonds between all carbon atoms
Nuclear Pore
a hole in the nuclear envelope
Polymer
a long molecule composed of similar subunits (monomers)
Polypeptides
a long polymer of amino acids
Nucleic Acid
a long polymer of nucleotides; DNA or RNA
prehensile tail
a long tail that can grip and hang onto a branch as hard as a hand
Flagella
a long whiplike appendage a cell uses for motility
pH Scale
a measurement of how acidic or basic a solution is
Vesicles
a membrane-bounded sac that transports materials in a cell
Solution
a mixture of a solute dissolved in a solvent
Electrons
a negatively charged particle that orbits the atom's nucleus
Amino Acids
a nitrogen atom single-bonded to two hydrogen atoms
Nitrogenous Base
a nitrogen-containing compound that forms part of a nucleotide
nare
a nostril
Protons
a particle in an atom's nucleus carrying a positive charge
Neutrons
a particle in an atom's nucleus that is electrically neutral
Atom
a particle of matter; composed of protons, neutrons, and electrons
chromatophore
a pigment-containing cell that allows some animals to change color in order to regulate body temperature or to camouflage themselves from predators
Protein
a polymer consisting of amino acids and folded into its functional three-dimensional shape
adaptive radiation
a process by which members of a species evolve in different ways to take advantage of different environments. In the history of chordate evolution, the appearance of new adaptations, such as jaws and paired appendages, often led to adaptive radiation.
feedback inhibition
a process in which the response to a stimulus counters the action of the stimulus
Element
a pure substance consisting of atoms containing a characteristic number of protons
Disaccharides
a simple sugar that consists of two bonded monosaccharides
Organism
a single living individual
Monomer
a single unit of a polymeric molecule
mucus
a slippery fluid
Reactants
a starting material in a chemical reaction
Ribose
a structure built of RNA and protein where mRNA anchors during protein synthesis
Ribosomes
a structure built of RNA and protein where mRNA anchors during protein synthesis
Nucleolus
a structure within the nucleus where components of ribosomes are assembled
Monosaccharides
a sugar that is one five- or six-carbon unit
Golgi Apparatus
a system of flat, stacked, membrane-bounded sacs that packages cell products for export
Scientific Method (PURPOSE)
a systematic approach to understanding the natural world based on evidence and testable hypotheses
Experiment
a test of a hypothesis under controlled conditions
Hypothesis
a testable, tentative explanation based on prior knowledge
nictitating membrane
a third eyelid that can be drawn across the eye for protection or moisture, but that can still be seen through
Roundworms (Phylum Nematoda)
abundant and mostly tiny -pseudocoelomates and have simplified body plan -have tubular gut and fluid-filled pseudocoelom that surrounds the organs -a rough, flexible, nonliving cuticle encloses and protects the thin, elongated body and is periodically molted -Nematodes lack circulatory and respiratory systems -have low energy requirements, diffusion suffices for gas exchange and distribution of nutrients -most reproduce sexually - no hermaphrodites *Roundworms harmful to humans -Hookworm larvae bore into human feet and travel to the intestine where they casue continuous bleeding -Trichinella- worms infect people who eat improperly cooked meats -Heartworms- transmitted to dogs by bite of infected mosquito
Animals that don't have a body cavity are called
acoelomates
The lizard's detachable tail and the slime produced by the hagfish are
adaptations in body structure that allow those animals to survive in their environment. These two animals are, by no means, the only animals where structure allows for specialized function.
Reptiles
adapted for life on land (birds, lizards, snakes, alligators, crocodiles) -evolved from an amphibian ancestor -have scales and shelled eggs -3 notable adaptations that allowed the reptiles freedom from their aquatic orgins 1. reptiles evolved a tough, scaly skin that protects the body and resists water loss 2. reptiles evolved internal fertilization, where the male deposits sperm in the female's body 3. reptiles evolved a shelled amniotic egg, which can be buried in sand/dirt, far from water -shell prevents the embryo from drying out on land -they have more efficient lungs than amphibians -they don't use their skin as a respiratory organ -their circulatory systems include 3/4 chambered hearts that segregate oxygenated and deoxygenated blood more effectively than do amphibian hearts Lizards & snakes share a common evolutionary heritage - they form a distinct linage whose ancestors had limbs, limbs retained by lizards Alligators & crocodiles adapted for life in water Turtles have protective shells
Polyp
adapted to life spent quietly attached to rocks -polyp has tentacles that reach upward to grasp and immobilize prey -typically reproduce by asexual budding in which the polyp produces miniature versions of itself
Animals with tissues exhibit either radial or bilateral symmetry
all animals w/ true tissues have symmetrical bodies -an animal is symmetrical if it can be bisected along at least 1 plane resulting in halves that're mirror images of each other
R Group
an amino acid side chain
In 2009, scientists announced the discovery of a skeleton that they do believe is
an ancestor of modern humans. The skeleton, nicknamed "Ardi," belonged to a bipedal female with a brain about the size of a chimpanzee's and long arms that likely helped her climb trees. This Ardipithecus ramidus skeleton has been determined to be about 4.4 million years old.
Ion
an atom or group of atoms that has lost or gained electrons, giving it an electrical charge
Bulk Elements (Organic and Mineral)
an element that an organism requires in large amounts
Trace Elements
an element that an organism requires in small amounts
chordate
animal that has a dorsal, hollow nerve cord, a notochord, a tail that extends beyond the anus, and pharyngeal pouches at some time during its life cycle
Bilateral Symmetry
animals can be divided into halves along one particular plane -have heads on anterior part -are motile (move under their own power)
Which of the following is a segmented worm with a true coelom?
annelid
Variable
any changeable element in an experiment
Constants (Standardized Variable)
any factor held constant for all subjects in an experiment
Isotope
any of the forms of an element, each having a different number of neutrons in the nucleus
Radial Symmetry
any plane through a central axis divides the object into equal halves -animals tend to either be sessile (fixed to 1 spot) or to drift around on currents (like jelly fish)
Efficient gas exchange is required to supply adequate oxygen to muscles
aquatic arthropods: gas exchange is accomplished by gills terrestrial arthropods: gas exchange is performed either by lungs or by tracheae
Most primates live in trees, which means they are mostly
arboreal
Chordates
are characterized by deuterostome development and a body plan that includes bilateral symmetry, cephalization, three germ layers, a true coelom, and segmentation.
Which of the following is a segmented animal with an exoskeleton and jointed appendages?
arthropod
Radioactive Isotope
atom that emits particles or rays as its nucleus disintegrates
Hydrophilic
attracted to water
Ionic Bond
attraction between oppositely charged ions
Chemical Bond
attractive force that holds atoms together
Most chordates develop a backbone made of bone or cartilage. These chordates belong to the vertebrate group. The invertebrate chordates, the tunicates and lancelets, exhibit all of the characteristics of chordates, but they do not have a backbone. Invertebrates that do not belong to phylum Chordata lack both a
backbone and a notochord.
Animals cannot survive if they do not maintain homeostasis. And, if an animal species is to survive, members of that species must also reproduce. Some animals reproduce asexually. Reproducing asexually allows an animal to reproduce quickly. However,
because only one parent is involved in asexual reproduction and all of the offspring are essentially genetically identical to that parent, genetic diversity is lost. This loss of genetic diversity can have disastrous results if the population encounters disease or adverse conditions. Sexual reproduction, on the other hand, requires two parents and results in greater genetic diversity. Greater genetic diversity in a population can help organisms adapt to environmental changes through the process of natural selection.
But trilobites were not the first animals. Scientists believe that the first animals evolved long before the Cambrian period. However,
because their tiny bodies are believed to have been soft, they didn't leave behind much fossil evidence. In 2006, however, scientists found the oldest evidence of multicellular life so far when they found a microscopic multicellular embryo from about 565 million years ago.
Acoelomates
bilateral animals with no body cavity (flatworms)
All primates have
binocular vision
Which of the following pairs of modern chordate groups are most closely related?
birds and crocodilians
Protostomes are animals in which the mouth forms from the
blastopore
Remember that a true coelom is a
body cavity that is completely lined with mesoderm.
coelom
body cavity that is lined entirely with mesoderm
A pseudocoelom is a
body cavity that is only partially lined with mesoderm
Pseudocoelom
body cavity that's not completely surrounded by mesoderm-derived tissue
Domains
broadest (most inclusive) taxonomic category
Nucleotide
building block of a nucleic acid, consisting of a phosphate group, a nitrogenous base, and a five-carbon sugar
Which of the following do all animals not need to do in order to survive
capture prey
Polysaccharides
carbohydrate consisting of hundreds of monosaccharides
Which of the following is an animal waste product?
carbon dioxide
The first of these derived characters is the development of vertebrae between hagfish and lampreys. Hagfish are eel-shaped, slime-producing marine animals. They have four hearts, but no jaws or stomach. They are unique in the animal world because they have a partial skull, but no vertebrae. Lampreys are also eel-like and they don't have jaws either. Instead, they have a tooth-filled sucker. Unlike hagfish, lampreys do have vertebrae. However, their vertebrae are not made of bone like those of most other vertebrates. Instead, their skeleton is composed of
cartilage, which is a strong connective tissue that is softer and more flexible than bone.
Bony fish have skeletons of true bone. Sharks and their relatives, which evolved before true bone appeared, have skeletons made of
cartilage. The oldest known bony fish fossils are about 420 million years old. Less than 100 million years after bony fish are thought to have evolved, the development of lungs allowed some chordates to breathe air.
Which of the following is not a characteristic of primates?
cartilaginous skeleton
Nucleus
central part of an atom; also, the membrane-bounded sac that contains DNA in a eukaryotic cell
More complex animals also tend to have their sense organs and nerve cells grouped at the anterior, or front end, of their bodies. This end is often different enough that it's called a head. This evolutionary tendency is called
cephalization
Periodic Table
chart that lists elements according to their properties
Instead of bone, however, an arthropod's skeleton is made up of
chitin. You may recall that chitin is also the main component in the cell walls of fungi.
Tunicates are invertebrates, but they are also
chordates
Mollusks (Phylum Mollusca)
clams, snails, and cephalopods -most mollusks have open circulatory systems (blood not confined to heart and blood vessels) -blood percolates through a hemocoel (blood cavity), bathing the internal organs directly -they have extension of the body wall called mantle that forms a chamber for the gills and, in shelled species, secretes the shell -nervous system is similar to annelids (ganglia connected by ventral nerves) more gnaglia are concentrated in the head -REPRODUCE SEXUALLY
Primates also have
clavicles, which give them a wide range of arm movement; without it, monkeys would be unable to swing through trees. Unlike other mammals, primates have nails instead of claws. This allows for greater dexterity and manipulation of tools.
Green Algae (early plants arose from this)
closely related to land plants -these are photosynthetic protists that may be multicellular/unicellular -some species (Spirogyra) form thin filaments of long chains of cells -other species form colonies containing clusters of cells that are somewhat interdependent and form a structure intermediate between unicellular and multicellular forms
Echinoderms are the only deuterostome invertebrates and are, therefore, considered to be
closer relatives to chordates than the other invertebrates.
Which of the following is a radially symmetrical animal with stinging tentacles?
cnidarian
The simplest animals that have body symmetry are the
cnidarians
The simplest animals with body symmetry and specialized cells and tissues are
cnidarians
Most complex animals have a fluid-filled space between their digestive tract and the body wall. This space is called a
coelom
cloaca
common opening in which reproductive cells and solid and liquid waste are expelled from the body
Organelles
compartment of a eukaryotic cell that performs a specialized function
Organic Molecules
compound containing both carbon and hydrogen
Carbohydrate
compound containing carbon, hydrogen, and oxygen in a ratio 1:2:1
Cephalization
concentration of sensory organs and a brain in a defined head region the head contains sensory cells, sensory organs, clusters of nerve cells, and organs for ingesting food
The classifications vertebrate and invertebrate are informal groupings. They make it easier to talk about such a large group of organisms. However, because the invertebrate grouping depends on a feature that these organisms lack (a backbone) rather than something they share, scientists do not
consider it a true clade. Remember that a clade is one common ancestor and all of its descendants, living and extinct, that share a set of derived characters.
Red Algae
contain red photosynthetic pigments -multicellular, photosynthetic seaweeds that're almost exclusively marine -pigment- range in color from red to black, masks their green chlorophyll -they predominate in deep, clear waters, their red pigments absorb the deeply penetrating blue-green light and transfers this light energy to chlorophyll for photosynthesis -some species deposit calcium carbonate in their tissues and contribute to the formation of reefs
Endothermy, an adaptation that arose in both birds and mammals, is the ability to
control body heat. All of these adaptions allowed different chordates to colonize all of the different environments that they live in today.
Evolution
descent with modification; change in allele frequencies in a population over time
In chordates and echinoderms, the blastopore becomes the anus and the mouth develops from a second opening that appears after the blastopore. Animals in which the blastopore becomes the anus are called
deuterostomes
Natural Selection
differential reproduction of organisms based on inherited traits
The acquisition of nutrients and their distribution to body systems is a function of the
digestive and circulatory systems.
Fossil evidence strongly supports the hypothesis that birds evolved from a group of-
dinosaurs
Eukarya
domain containing eukaryotes
Which of the following is a radially symmetrical deuterostome invertebrate most closely related to chordates?
echinoderm
Monotremes (mammal group)
egg-laying mammals -they lay eggs rather than giving birth to live young includes the platypus
Amniotic eggs, which are eggs protected by a membrane, allowed for
embryonic development on land without the danger of drying out. Amniotic eggs are thought to have evolved in early reptiles about 360 to 268 million years ago.
Marsupial (mammal group)
embryos develop in uterus, a muscular organ in female reproductive tract -lining of the uterus combines with membranes derived from embryo to form placenta -embryos develop in uterus only for short period -young are born at very immature stage of development -immediately after birth, marsupial crawls to nipple and completes development
Body plants evolve as adaptations that
enable members of a phylum to survive and reproduce
Germ layers include
endoderm (innermost), mesoderm (middle), and ectoderm (outermost). Sponges do not show germ layer differentiation. Cnidarians have two germ layers. All other animals have all three germ layers.
In most animals, there are four main types of tissues—
epithelial, muscle, connective, and nervous tissue.
Endomembrane System
eukaryotic organelles that exchange materials in transport vesicles
Peer Review
evaluation of scientific results by experts before publication in a journal
Endothermic (warm-blooded) animals
ex. birds have high metabolic rate which increases the demand for energyand requires efficient oxygenation of tissues -therefore birds must eat frequently
Which body system do animals use to eliminate waste, such as ammonia?
excretory system
Arthropods also have a hard outer covering called an
exoskeleton
Primates are an order of mammals that includes monkeys, apes, and humans. Primates are characterized by various traits, including
eyes that are positioned facing forward. This arrangement provides primates with stereoscopic vision, giving them better depth perception. This is especially helpful for monkeys since they maneuver through trees.
Birds (reptiles)
feathered reptiles -their anatomy and physiology are dominated by adaptations that help them fly -birds are exceptionally light for their size -many bones present in other reptiles have been lost in the course of evolution/fused with other bones -bones of the bird skeleton are lightweight -reproductive organs shrink considerably during nonbreeding periods; females possess only a single ovary, further minimizing weight -feathers serve as lightweight extensions of the wing and tail surfaces that provide lift required for flight and provide lightweight protection and insulation for the body -birds maintain body temperatures high enough to allow their muscles and metabolic process to operate at peak efficiency -this supplies the bird enough power to fly regardless of the temperature of the external environment -their 4 chambered heart prevents mixing of oxygenated and deoxygenated blood -resp. system is supplemented by air sacs that provide a continuous supply of oxygenated air to the lungs, even while the bird exhales
One of the ways an animal's body maintains homeostasis is though a process called
feedback inhibition. Feedback inhibition is also called negative feedback. For feedback inhibition to occur, the body's response to a stimulus must cause a reaction that counters that stimulus.
zygote
fertilized egg
Bivalves
filter feeders (scallops, oysters, mussels, and clams)
Which of the following is an unsegmented acoelomate worm?
flatworm
Medusa
floats in water and carried by currents -bell-shaped body of the medusa has trailing tentacles like multiple fishing lines
Coelom (most common body cavity)
fluid-filled body cavity that's completely lined with a thin layer of tissue developed from mesoderm
Cristae
fold of the inner mitochondrial membrane along which many of the reactions of cellular respiration occur
All animals need certain things to survive. They need
food and water. They need oxygen and a suitable place to live, too. Oh, and one more thing—they need to keep from being eaten!
Whether they live in the desert, in the forest, or underground, all animals need
food, water, and oxygen. And they need to be able to get the nutrients and oxygen to all the cells in their bodies. They also need to be able to eliminate wastes, maintain homeostasis, and reproduce. An animal's body is a living system. It requires inputs—food, water, and oxygen. It also has outputs—waste. As with all systems, an organism's inputs and outputs must be balanced in order for the organism to continue to survive.
Asexual Reproduction
form of reproduction in which offspring arise from only one parent
Mesoderm
forms muscle, and when present, the circulatory and skeletal systems
Because they are hard, exoskeletons are easily
fossilized. Remember that the hard parts of animals, such as their teeth and bones, are much more likely to be fossilized than soft body parts. Numerous fossils of one ancient arthropod, called a trilobite, have been found. In fact, people have found trilobite fossils on every continent on Earth. Trilobites lived from the lower Cambrian period, which was about 520 million years ago, to the end of the Permian, about 240 million years ago. They went extinct about five million years before dinosaurs came about.
Scientists believe that anthropoids split into two groups when the continents split apart 45 million years ago. One of these groups can be
found in Central and South America and is called the New World monkeys. The other group of anthropoids evolved in Africa and Asia. This group includes the Old World monkeys and the great apes, or hominoids.
In the absence of a respiratory system
gas exchange is accomplished by diffusion between body cells and the environment
DNA
genetic material consisting of a double helix of nucleotides
Which of the following animals are considered hominoids?
gibbons and orangutans
hominoid
great apes; includes gibbons, orangutans, gorillzas, chimpanzees, and humans does not include tarsiers.
Chordates include 3 clades
groups that include all of the descendants of a common ancestor 1. tunicates 2. lancelets 3. craniates
vertebrates
have a backbone -are animals in which the embryonic notochord is replaced during development by a backbone/vertebral column, composed of bone/cartilage -vertebral column of the vertebrate : supports its body, provides attachment sites for muscles, protects the delicate nerve cord and brain, and is part of a living interna skeleton that can grow and repair itself
Lobsters and insects do have some things in common. Both have bodies that are divided into segments and they both have jointed legs. They both
have a head and an exoskeleton. And they belong to the same phylum—Arthropoda.
Chlade - Craniates
have a skull (all chordates that have a skull that encloses the brain) skull may be composed of bone or cartilage -early craniates resembled lancelets but had brains, skulls, and eyes -the mouths of the earliest craniates lacked jaws -Subgroups: hagfishes and vertebrates
Echinoderms (Phylum Echinodermata)
have calcium carbonate skeleton (sand dollars, sea urchins, star fish) -they are bilaterally symmetrical as larvae and radially symmetrical as adults -exhibit deuterostome development
Stramenopiles (Photosynthetic)
have distinct flagella -all members of the group have fine, hair-like projections on their flagella -some are photosynthetic and some are not -most are single-celled but some are multicellular -subgroups: diatoms, brown algae (photosynthetic) Diatoms: encased within glassy walls -they're photosynthetic stramenopiles that produce protective shells of silica(glass) -these shells consist of top and bottom halves that fit together like a pillbox -found in fresh and salt water -accumulations of fossil deposits of diatoms form the "diatomaceous earth" used commercially as a mild abrasive -form part of the phytoplankton, single-celled phtosynthesizers that float passively in the Earth's lakes and oceans -marine phytoplankton account for 50% of all photosynthetic activity on earth -they absorb carbon dioxide, recharging atmosphere with oxygen Brown Algae: multicellular -some photosynthetic protists form a group of stramenopiles that have multiceullar aggregations called seaweeds -named for brownish-yellow pigments that increase the seaweed's ability to gather light -almost all are marine (salt water) -the group includes dominant seaweed species found along rocky shores in temperate oceans of the world
Euglenozoans
have distinct mitochondria subgroup- euglenids genus-euglena -euglenids lack a rigid covering and swim by flagella -they're single-celled protists that live mostly in freshwater -many are photosynthetic -some possess simple light-sensing organelles consisting of a photo receptor called an eye spot and an adjacent patch of pigment (gives ability to detect light and its direction)
Coelacanths & lungfishes (ancient fish)
have lobed fins -some bony fishes are members of 2 groups: coelacanths (Actinistia) and lungfishes (Dipnoi) -6 species of lungfishes are found in freshwater -have gills and lungs -tend to live in stagnant waters low in oxygen -some lineages of lobefins left descendants that survive today - survivers are tetrapods which have limbs instead of fins (amphibians, reptiles, and mammals)
Myriapods
have many legs (centipedes, millipedes) -have one pair of aantennae -have simple light-detecting eyes -respire by tracheae Centipedes- one pair of legs per body segment Milli- 2 pairs of legs per body segment
thympanum
hearing structure
Nerves branch in intervals from which of the following structures in a chordate embryo?
hollow nerve chord
Dorsal nerve cord
hollow nerve cord above the digestive tract, running lengthwise along the dorsal portion of the body
Remember that homeostasis is a relatively stable internal environment. An animal's body systems—its circulatory system, respiratory system, digestive system, musculoskeletal system, nervous system, and excretory system—work together to maintain
homeostasis
To survive, all animals must maintain
homeostasis. Remember that homeostasis is a relatively constant internal environment. To do this, all animals need to gather and respond to information in their environment, obtain and distribute nutrients and oxygen throughout their bodies, and collect and eliminate waste. An animal's body systems—its circulatory system, respiratory system, digestive system, excretory system, musculoskeletal system, and nervous system—all work together to maintain homeostasis.
The hominids in the linage that led to modern humans are called
hominines. At some point in hominine evolution, the shape of the skull, spinal cord, pelvis, and thighbones changed to allow early hominines to walk upright on two feet.
Today, scientists call the primate lineage that led to modern humans,
hominines. Humans are the only surviving members of the hominine lineage. The development of bipedality was a very important development in the evolution of hominines. Scientists are not exactly sure when or why hominines developed the ability to walk on two feet, but they hypothesize that it may have been to free both hands to carry food or to use tools.
hominine
hominoid lineage that led to humans
Overview: Primates
https://www.connexus.com/content/render.aspx?idDocument=2821259
Lipids
hydrophobic organic molecule consisting mostly of carbon and hydrogen
Independent Variable
hypothesized influence on a dependent variable
larvae
immature life stage of some animals
Placebo
inert substance used as an experimental control
Statistical Significance
inert substance used as an experimental control
Placental mammals
inhabit land, air, and sea -most mammal species are placental mammals -their placentas are far more complex than those of marsupials -they retain their young in the uterus for longer period - offspring complete their embryonic development before they're born -largest groups of placental mammals are the rodents and bats -rodents account for 40% of all mammal species -20% are bats
Adaptation
inherited trait that permits an organism to survive and reproduce
Endoderm
inner layer, which gives rise to tissues that line the gut cavity -in bilaterally symmetrical animals, the endoderm differentiates to form the tissues that line most hollow organs, respiratory surfaces, and the gut
Primates are very
intelligent and are known to be able to solve complex problems, form relationships, and learn new skills for finding food and functioning in social groups.
Endoplasmic Reticulum
interconnected membranous tubules and sacs in a eukaryotic cell
Many animals with bilateral symmetry develop repeated parts, or segments, during development. Segmented animals have some
internal or external body part that repeats on each side of its body. Chordates, for example, are segmented, bilaterally symmetrical animals. They have appendages on either side of their bodies. Some have arms and legs while others have wings or flippers.
Scientists divide animals into two general categories—
invertebrates and vertebrates
At some point, between lampreys and sharks, chordates developed
jaws and paired appendages. Fish with jaws first appear in the fossil record about 425 million years ago.
Sensing and responding to the environment in order to maintain homeostasis does not just mean getting away from predators. It can also mean
keeping the body at the correct temperature. Reptiles, for example, cannot regulate their own body temperature. They must rely on sources of heat in their environment instead. This is why you might find a lizard stretched out on a rock in the sun. It helps them warm up.
Plantae
kingdom consisting of multicellular, eukaryotic autotrophs
Animalia
kingdom containing multicellular eukaryotes that are heterotrophs by ingestion
Which of the following primates have the best sense of smell?
lemurs
Small, nocturnal primates with large eyes adapted to seeing in the dark include-
lemurs and lorises
Sterols
lipid consisting of four interconnected carbon rings
Triglycerides
lipid consisting of one glycerol bonded to three fatty acids
Amphibians - class Amphibia
live a double life -early tetrapods that made the 1st vertebrate invasion of land were the amphibians -limbs of amphibians show varying degrees of adaptation to movement on land -they have 3-chambered heart that circulates blood more efficiently -most adults respire through lungs and moist skin -most have 4 limbs -reproduce sexually using external fertilization -most are confined to moist habitats by their breeding behavior which requires water -fertilization in frogs & toads - generally external and takes place in water, where the sperm can swim to their eggs -eggs must remain moist, because they're protected only by a jelly-like coating that leaves them vulnerable to water loss by evaporation -adult frogs and toads move by hopping and leaping -frogs have smooth and moist skin, toads have bumpy drier skin
Pharyngeal gill slits
located in the pharynx appear as grooves during early stage of development
Fatty Acids
long-chain hydrocarbon terminating with a carboxyl group
Generally, primates have
longer gestation periods and longer lifespans than other mammals their size.
Primates that have a long, prehensile tail are called
lorises
Which of the following must an animal do to survive?
maintain homeostasis
Cephalopods
marine predators (octopuses, squids) -they're predatory carnivores and all are marine -they have highly developed brains and sensory systems -tentacles are used for locomotion and to capture prey -they are able to move rapidly by forcefully expelling water from the mantle cavity -possess closed circulatory systems (efficient system)
Cartilaginous fishes
marine predators Class - Chondrichthyes (sharks) -most are marine -possess jaws and cartilaginous skeleton -body is protected by a leathery skin embedded with tiny scales -most are predators of larger prey such as fishes, marine mammals, sea turtles, crabs, etc -most sharks avoid humans but some can be dangerous -internal fertilization
Vacuole
membrane-bounded storage sac in a cell, especially the large central vacuole in a plant cell
A true coelom develops within the mesoderm and the space is completely lined with
mesoderm
Pseudocoelomates have a body cavity, but the space is only partially lined with
mesoderm
Denature
modification of a protein's shape so that its function is destroyed
Phospholipids
molecule consisting of two hydrophobic fatty acids and a hydrophilic phosphate group
Which of the following is a unsegmented animal with a free swimming larval stage?
mollusk
The order Primate includes
monkeys, lemurs, orangutans, gorillas, chimpanzees, and humans. Today, there are around 250 living primate species. The smallest primate, the pygmy mouse lemur, weighs about an ounce (30 g) and could sit in the palm of your hand. The largest primate, the gorilla, weighs around 400 pounds (181 kg)
The embryonic development of complex animals also differs from those that are
more primitive.
Arthropods
most diverse and abundant animals -no other phylum comes close to the arthropods (insects, arachnids, myriapods, and crustaceans) -they have appendages and an exoskeleton -they have paired, jointed appendages and an exoskeleton (external skeleton that encloses the body like a suit of armor) -exoskeleton is secreted by the epidermis (outer layer of skin) composed primarily of protein and chitin (a polysaccharide) -have specialized segments and adaptations for active lifestyles -head (front segment) contains sensory and feeding structures -abdomen (rear segment) contains digestive structures -thorax (between head and abdomen) site for attachment for locomotion structures -most possess well-developed sensory and nervous systems -arthropod sensory systems often include compound eyes that have multiple light detectors and acute chemical and tactile senses -the well-developed nervous system, combined with sophisticated sensory abilities, has permitted the evolution of complex behaviors in many arthropods
Ray-finned fishes
most diverse and abundant vertebrates -bony fish are found in nearly every watery habitat, both fresh and marine water -distinguished by the structure of their fins, which are formed by webs of skin supported by bony spies -they have bony skeleton -2 chamber heart -skin is covered with interlocking scales -most have a swim bladder that allows them to float effortlessly at any level in the water (snakelike eels - flattened flounders) -they're important human food source -populations of almost all economically important ray-finned fish species have declined drastically due to increased efficiency in their capture by humans
Along with bipedality, hominines also developed
much larger brains than their closest living relatives, the chimpanzees. On average, a human's brain is a little over 25 percent larger than a chimp's. Most of the difference comes from a markedly larger cerebrum. The cerebrum is the part of the brain that is responsible for learning, memory, and conscious thought.
Sponges might not look much like animals. They don't have brains, or hearts, or stomachs. They don't have muscles, a mouth, or lungs, either. But they are
multicellular, eukaryotic heterotrophs. And, most importantly, their cells do not have a cell wall.
Neutral pH
neither acidic nor basic. Also, not electrically charged
RNA
nucleic acid typically consisting of a single strand of nucleotides
Sample Size
number of subjects in each experimental group
In absence of circulatory system
nutrients move directly from digestive tract to body cells
Before the discovery of Ardi, "Lucy" was the oldest known
oldest known hominine fossil. This Australopithecus afarensis skeleton was found in 1974. The skeleton belonged to an adult female and is about 3.2 million years old. In 2006, scientists found an even more complete A. afarensis skeleton. This one belonged to a young female and has been nicknamed the "Dikika Baby."
Through evolutionary processes, many of the primates' _____________ receptors have been deactivated.
olfactory
Most primates are
omnivores
pharyngeal pouch
one of a pair of structures found in the throat region of chordates
Bacteria
one of two domains of prokaryotes
Gastropods
one-footed crawlers -snails and slugs are known as gastropods -have a muscular foot for locomotion -possess a shell, but not all gastropods are shelled -most snails use gills, typically enclosed in a cavity beneath the shell, for respiration ~gases can diffuse readily through skin of most gastropods -some use a simple lung for breathing
All primates also have
opposable thumbs and fingers, which enable them to grasp things. Primates' limbs are different from other animals' limbs in that they contain two bones in the forearm and lower leg, allowing for greater precision in movement.
Lysomes
organelle in a eukaryotic cell that buds from the Golgi apparatus and enzymatically dismantles molecules, bacteria, and worn-out cell parts
Eukaryotes
organism composed of one or more cells containing a nucleus and other membrane-bounded organelles
Groups of tissues make up
organs, and organs work together in organ systems to meet the animal's basic needs. Sponges have some specialized cells, but they lack tissues and organs. Sponges also lack symmetry. They are asymmetrical. But the bodies of other animals exhibit some sort of symmetry.
Ectoderm
outer layer, gives rise to tissues that cover outside of the body -forms nerve tissue and tissue on outer surface of body
Lampreys
parasitize fish -jawless -have a large rounded sucker that surrounds the mouth -have single nostril on top of the head -spinal cord is protected by cartilaginous segments -live in fresh and salt waters -some are parasitic - use tooth-lined mouth to attach itself to a larger fish
All primates have five fingers, a characteristic called
pentadactylism
The invertebrate group also includes several different
phyla of worms. Like flatworms, nematodes, or roundworms, are unsegmented worms. However, roundworms possess a pseudocoelom while flatworms do not. The phylum Annelida, which includes earthworms, contains segmented worms with a true coelom.
Coelomates
phyla with animals that have coelom body cavity (annelids, arthropods, mollusks, echinoderms, and chordates)
Pseudocoelomates
phyla with animals that have pseudocoelom body (roundworms)
Smooth ER
portion of the ER that produces lipids and detoxifies poisons
In which grip is the thumb used as a counter force?
power grip
When you are doing holding a fork, you are using a
precision grip.
An exoskeleton
protects and supports an arthropod's body like your internal skeleton protects and supports your body.
In most invertebrates, the blastopore becomes the mouth. At the other end of the tube, the anus is formed. Animals in which the blastopore becomes the mouth are called
protostomes
Mammals
provide milk to their offspring -they didn't diversify and dominate land until dinosaurs became extinct -they have sweat, scent, and sebaceous (oil-producing) glands, where aren't found in other vertebrates -mammalian brain is highly developed -mammals have unparalleled curioustiy and learning ability, allowing them to alter their behavior based on experience - this increases chances of survival in changing environment -they have extended parental care after birth - # of young is less because so much care is put into them so chance of survivals higher -large brains of humans hve been the major factor leading to human domination of Earth - our brains compensate for physical disadvantages
From teeth to thighs to tiny toe bones, scientists have found the fossil remains of more than 6,000 individuals. Since scientists discovered the fossil skeleton nicknamed "Lucy" in 1974, additional fossil finds and improved technologies have nearly doubled the branches on the hominine family tree. And, with new bones being found every year, scientists continue to
put together a better, more complete picture of the earliest human ancestors.
The nervous systems of complex animals gather information using cells called
receptors
Hydrophobic
repelled by water
The Cambrian Explosion resulted in the evolution of the
representatives of the most animal phyla
Dependent Variable
response that may be under the influence of an independent variable
Rough ER
ribosome-studded portion of the ER where secreted proteins are synthesized
Which of the following is an unsegmented worm with a pseudocoelom?
roundworm
Ancient chordates are thought to be most closely related to which of the following species?
sea stars
Annelids (Phyla Annelida)
segmented worms - leeches, earth worms -bodies are divided into a series of similar repeating segments Externally, segmentation appears as series of ringlike depressions on the surface Internally, most of the segments contain identical copies of nerves, excretory structures, and muscles -sexual reproduction is common among annelids - some species are hermaphroditic -during copulation, sperm are transferred from one individual to the other -annelids have a fluid-filled coelom between the body wall and digestive tract -coelom functions as a hydrostatic skeleton, where pressurized fluid provides a framework against which muscles can act -they have a closed circulatory system that distributes gases and nutrients throughout the body ~in closed ciculatory systems, blood is confined to the heart and blood vessels -blood is filtered and wastes are removed by excretory organs called nephridia
Fossil evidence has shown that
several Homo species existed before Homo sapiens appeared. It also appears that at least three other Homo species—Homo neanderthalensis, Homo erectus, and Homo floresiensis—existed at the same time as early Homo sapiens.
Sponges - Phyla Porifera
simple sessile animals (stay in one place) -found in most aquatic environments -lack tissues
You may recall that an exoskeleton is a hard outer coating. This hard outer coating is actually the animal's
skeleton
Hagfishes (subgroup of craniates)
slimy residents of ocean floor -lack jaws -bodies are stiffened by a notochord -most systematists don't consider hagfish as vertebrates because they lack skeletal elements -respire using gills, have 2-chambered heart, are ectothermic (rely on heat from outside environment to regulate body temperature) -feed primarily on worms -secrete massive quantities of slime as defense against predators
Cell
smallest unit of life that can function independently
Cells
smallest unit of life that can function independently
Adaptive radiation is thought to have driven the evolution of
some of the more important chordate adaptions. Remember that adaptive radiation is the process by which a single species or a small group of species evolves into several forms in order to thrive in different environments.
The most ancient members of the kingdom Animalia are
sponges
Matter
substance that takes up space and is made of atoms
Suppose scientists could compare the DNA of modern humans from around the world with the DNA of Homo erectus populations from the humans' native homelands. If DNA samples from modern humans were found to be most similar to the Homo erectus DNA from their homeland, that finding would
support the multi-regional model
Kingdoms
taxonomic category below domain
Genus
taxonomic category that groups closely related species
The development of four limbs allowed animals to crawl out of the water. Vertebrates with four limbs are called
tetrapods. In 2010, Polish scientists found the oldest known fossil footprints made by a tetrapod. These footprints are about 395 million years old. This is about 20 million years earlier than scientists had previously thought tetrapods had moved onto land.
While many of the animal fossils that scientists have found have come from the Cambrian Period, recent discoveries in microfossils have led scientists to believe that
that the first animals actually evolved long before this period.
Homeostasis
the ability of an organism to maintain a stable internal environment despite changes in the external environment
Primary Structure
the amino acid sequence of a protein
You may recall that cephalization means that the animal's body has a distinct head region where sense organs and nerve cells are concentrated. Segmentation means that
the animal's body is divided into several repeated parts. Insects, for example, have three body parts and three pairs of jointed legs. In fact, all arthropods have joined appendages.
Cohesion
the attraction of water molecules to one another
Atomic Weight
the average mass of all isotopes of an element
pseudocoelom
the body cavity of invertebrate metazoan animals where the body wall meets the intestine not lined with a mesodermal epithelium.
Cell Membrane
the boundary of a cell, consisting of proteins embedded in a phospholipid bilayer
What binds the cells in a sponge together?
the cells in a sponge are bound together with collagen fibers
Sexual Reproduction
the combination of genetic material from two individuals to create a third individual
Remember that the blastopore is
the first opening that forms in the blastula, or hollow ball of cells that develops when a zygote starts to grow.
Cell Theory
the ideas that all living matter consists of cells, cells are the structural and functional units of life, and all cells come from preexisting cells
A primate's forward-facing eyes allow
the images from both eyes to be combined, giving primates binocular vision and a 3D image of the world. They also tend to have arms that can rotate around the shoulder joint, allowing for easier climbing.
Matrix
the inner compartment of a mitochondrion
With well over a million identified species, arthropods are far more numerous than the next most plentiful animal phylum—
the mollusks. Scientists estimate that there are between 50,000 to 130,000 mollusk species. Snails, slugs, clams, mussels, squids, and octopi are all mollusks. Mollusks have internal shells
Deuterostomes are animals in which
the mouth forms from the second opening in the blastopore. Chordates, including humans, are deuterostomes.
According to evolutionary theory, all animals living today evolved from a common ancestor. The various animal phyla represent branch points from this ancestor. Some animals are more primitive than others. The complexity of animals is shown in
the number and type of germ layers present, the type of body cavity, whether the animal is a protostome or deuterostome, the presence or absence of segmentation, and the presence or absence of cephalization.
Animal body plans differ in
the number and type of germ layers present. They also differ in the formation of a body cavity.
Atomic Number
the number of protons in an atom's nucleus
Arthropods (Insects)
the only flying invertebrates -# of described insect species is about 850,000 -insects have a single pair of antennae -have 3 pairs of legs, usually supplemented by 2 pairs of wings -The 3 groups of insects are: 1. Butterflies and moths (very colorful) 2. Bees, ants, and wasps (capable of very complex social behavior, and they sting) 3. Beetles (1/3 of insects, hard protective exoskeleton)
Tertiary Structure
the overall shape of a polypeptide, resulting mostly from interactions between amino acid R groups and water
thorax
the part of the body between the head and the abdomen; the middle section of an insect's body
abdomen
the part of the body between the thorax and the pelvis
Modern humans belong to
the phylum Chordata, the class Mammalia, and the order Primate.
Products
the result of a chemical reaction
Taxonomy
the science of describing, naming, and classifying organisms
Quaternary Structure
the shape arising from interactions between multiple polypeptide subunits of the same protein
The sponges are considered
the simplest animals. They possess some specialized cells, but no body symmetry.
Adhesion
the tendency of water to hydrogen bond to other compounds
Mass Number
the total number of protons and neutrons in an atom's nucleus
Nuclear Envelope
the two membranes bounding a cell's nucleus
Cytoplasm
the watery mixture that occupies much of a cell's volume. In eukaryotic cells, it consists of all materials, including organelles, between the nuclear envelope and the cell membrane
One example of feedback inhibition that you may be familiar with is
the way an air conditioner works in a house. The air conditioner is set to a particular temperature. If the house gets too hot, the air conditioner turns on. This causes the temperature inside the house to drop. This response causes the air conditioner to turn off. Over time, the temperature goes up again and the air conditioner turns back on. By cycling on and off this way, the air conditioner keeps the environment inside the home relatively constant. An animal's body systems work in a similar way—they turn on in response to a stimulus and turn off when conditions return closer to a particular set point.
Today, scientists classify the major animal phyla by
their adult body plan and the pattern of their embryonic development (whether they are protostomes or deuterostomes). Each phylum has a combination of ancient characteristics and those that define the phyla. Roundworms, for example, are characterized by a body plan that includes bilateral symmetry, cephalization, and protostome development.
The one characteristic that sets all animals apart from the multicellular, eukaryotic, heterotopic members of the kingdoms "Protista, Fungi, and Plantae" is that-
their cells lack a cell wall.
The phylum Echinodermata includes sea stars, sea urchins, and sand dollars. Echinoderms are more closely related to chordates than they are to other invertebrates because of
their deuterostome development.
The phylum Mollusca includes snail, slugs, octopi, and clams. Mollusks may look very different from one another, but one thing they all have in common is that
their larvae are free-swimming. Larvae are immature forms that are a part of an animal's life cycle.
Gill slits are paired structures in a region of the throat called the pharynx. Because of their location,
they are also called pharyngeal pouches. In some animals, like mammals, the pharyngeal pouches disappear as the animal matures. In fish, however, the pharyngeal pouches develop into gills.
From sponge to bird to human, there is a huge diversity of form in the animal world. And, yet, many animals share an underlying body plan. Over millions of years, natural selection has acted on this basic plan and produced the enormous variation seen in animals today. Birds, whales, and octopi certainly have different features, but these features all have one thing in common—
they have all evolved to help the animals carry out their essential functions in their environments.
the difference between radially and bilaterally symmetrical animals reflects another major branching point in the animal evolutionary tree
this split separated ancestors of radially symmetrical cnidarians and ctenophores from the ancestors of the remaining animal phyla, all of which are bilaterally symmetrical
Invertebrates
those lacking a backbone -vast majority of animal species are invertebrates
Vertebrates
those with a backbone/vertebral column (fish, amphibians, reptiles, and mammals) -less than 3% of all known animals are vertebrates -animals probably originated from colonies of single-celled protists whose members had become specialized to perform distinct roles within the colony
The cladogram suggests that the Cambrian Explosion most likely took place after the development of which characteristics?
three germ layers
cartilage
tissue that resembles bone but is less brittle and more flexible
Each animal phylum has a unique body plan. As an animal develops, its cells differentiate and become specialized. These specialized cells form groups called
tissues
The first mammals resembled
tree shews
Even though they look quite different when they mature, most mollusks have a free-swimming larval stage called a
trochophore. Annelids, which include earthworms and leeches, also have a trochophore stage in their life cycles, providing evidence that mollusks and annelids probably shared a common ancestor.
During this free-swimming stage, the larvae are called
trochophores
In which type of climate do primates live?
tropical and subtropical
Molecule
two or more atoms joined by chemical bonds
Covalent Bond
type of chemical bond in which two atoms share electrons
Control
untreated group used as a basis for comparison with a treated group in an experiment
Comb jellies
use cilia to move -the roughly 150 species of radially symmetrical comb jellies (Ctenophora) are superficially similar to some cnidarians in appearance
Protists
use diverse modes of nutrition -ingest food -absorb nutrients from their surroundings -capture solar energy directly by photosynthesis
Which of the following variations would you expect to see in land vertebrates?
varying shapes of forelimbs
Orbitals
volume of space where a particular electron is likely to be
Bipedalism is the ability to
walk on two legs
Buffers
weak acid/base pair that resists changes in pH
Hydrogen Bond
weak chemical bond between opposite partial charges on two molecules or within one large molecule
Theory
well-supported scientific explanation
