ACC Life on Earth Biology Exam 3 prep

All of these are arthropods

1) Eurypterids, 2) Insects, 3) Millipedes, 4) Trilobites

1. What does "theory" mean to a scientist? 2. Contrast this with the use of "theory" by most people in everyday speech.

1. An overarching set of mechanisms of principles that explain a major aspect of the natural world. 2. A vague guess based on little evidence.

What are two possible ways that flight might have evolved?

1. Running and getting lift off 2. Climbing trees and gliding

Describe the lifestyle of the fractal animals found at Mistaken Point, Newfoundland, Canada.

Lived in dark, absorbed chemicals,They were immobile, simple and incapable of evolving.

How is the hair of the echidna modified?

Long and strengthened, turned into spines, used to keep it warm

What does that tell us about its lifestyle? (fossilized Markuelia embryos)

Predator: It ate other animals. Hunters began to exist. Life was exploding in diversity.

What was the impact of the evolution of predators upon their prey?

Prey had to evolve in response to their predators

Describe the body plan and lifestyle of Arthropleura. What environmental condition allowed it to get so big?

- Giant millipede, 27-28 segments, 8 feet, biggest terrestrial arthropod. - lots of oxygen in the atmosphere; 35%

Describe Anomalocaris. What is significant about this fossil animal?

- Had plates along its back, tail at the end, two spike claws, mouth with teeth - First big predator on Earth

How are early dinosaur feathers similar to the feathers found on today's birds?

- Had the same structures - Had raised bumps, just like the quill nodes on bird bones where feathers are anchored

How does the DNA of the daughter cells compare to the DNA of the parent cell?

daughter cells contain the same genetic information as the parent cell.

How did the addition of nutrient-rich melt water at the end of Snowball Earth result in the evolution of complex life forms?

- It was a fertilizer for the microbes in the water. - Cyanobacteria flourished which led to lots of oxygen. - Simple life forms eventually became more complex.

Discuss two characteristics of arthropods. Arthropods use their exoskeleton of chitin for what purposes?

- Jointed legs and hard armor plating - Use chitin for support

Define mutation.

random and accidental but permanent changes in DNA

Describe reproduction in the platypus.

- Lays eggs in a nest. - Feeds it with milk that oozes through the skin. - Born with an egg tooth that's used to cut itself out of the shell.

Name and briefly describe the three branches of mammals.

- Monotremes: lay shelled eggs, more similar to early mammals - Marsupials: pouched - Placental: womb, more developed at birth

Compare the wing of a pterosaur to the wing of Archaeopteryx.

- Pterosaur: has 4 digits - Archaeopteryx: 3 digits, individual feathers

Explain the role of the placenta and umbilical cord.

- Rich in blood vessels - Feeds and give nutrients to the baby

Explain the relationship between sexual reproduction and the ability to adapt quickly to changing environments.

- The arrival of sexual reproduction led to faster evolution because of greater genetic mutation. - Over generations, better able to adapt.

What does the comparison of modern-day mantis shrimp with Anomalocaris reveal about the lifestyle of Anomalocaris?

- They both wait for prey to come by and catch it with their claws - Anomalocaris was a formidable predator

Describe reproduction in the grey kangaroo.

- Tiny unshelled "worm" - Pulls itself into mother's pouch - Clips itself onto mother's nipple

What evidence found in mammal embryos today supports the idea that the middle ear bones were once attached to the lower jaw?

- When the bones of the ear first develop in mammal embryos, they are anchored to the lower jaw, as they were in the ancestors of mammals and other tetrapods. - Only later do they break free

Describe the mantis shrimp.

- lurks in barrows, uses claws to catch prey, good vision, speed

Genetic variation stems from what two processes?

- mutations - gene shuffling during sexual reproduction.

Describe the body plan of Pikaia. What was significant about this fossil animal?

- no teeth, no exoskeleton - 1st to have an internal backbone; ancestor to all vertebrates, from this evolved fish

Describe the two general factors that cause mutations.

1) Errors in Copying During Reproduction: Because there are billions of nucleotides in the DNA, there are many chances for mistakes to be made. Even with error-correcting enzymes in the cells, mistakes happen every so often during copying. 2) Direct Damage Caused by Exposure of Cells to Radiation or Harmful Chemicals: Exposure to ultraviolet light from the sun, radioactivity or certain chemicals (such as toxins or pollution in the environment) can change the DNA molecules so that they don't work right. Because all life is based on DNA, all living things are susceptible to these same harmful effects.

How old are the Funisia fossils?

1,200 million years old

List several adaptations found in birds that reduce weight.

1. Beak 2. less bones in the skeleton 3. hollow bones 4. feathers

Describe the amniotic egg and the function of each membrane

1. The amnion that makes amniotic fluid to bathe the embryo and cushion it. 2. The chorion that is involved in gas exchange. 3. The allantois that is involved in metabolic waste disposal. 4. The yolk sac contains yolk which provides the embryo with nutrients.

What changes occurred in the skulls of mammals, with respect to: 1. the dentary 2. middle ear bones 3. other bones in the lower jaw

1. became larger 2. separated from the jaw 3. some disappeared, some became art of the ear, evolved into a series of levers that could amplify faint high-frequency sounds

When did the first platypus appear in the fossil record?

100 million years ago.

When did mammals evolve?

180 million years ago

What percentage of oxygen is found in today's atmosphere?

21%

How long were simple microscopic organisms the only life forms on Earth?

3 billion years

Like "Archaeopteryx," the modern hoatzins also have ______ fingers, each ending in ______, which allow young birds to ______.

3, a hooked claw, cling onto twigs

A new group of arthropods, the insects, evolved with _______________ pairs of legs and __________________ for flying.

3, wings

When did life arise in this environment?

3.5 billion years ago

How old are the Carboniferous plant fossils found in Crail?

335 million years

How old are Tiktaalik?

375 Million years old

How old are the Burgess Shale fossils?

542 million years

How old are the Ediacaran fossils?

550 million years old

How old are the fossils of the fractal animals found at Mistaken Point, Newfoundland, Canada?

579 million years

How old are Charnia fossils?

600 million years old.

Describe sexual reproduction.

= meiosis each offspring gets half of its DNA from each of its two parents, so each offspring is genetically different from both parents and from other offspring of the same parents.

This large Cambrian animal is the first-known large predator. Its body had a mouth with teeth, two claws with spikes, armored plates along its sides, and a tail.

Anomalocaris

Describe the fossil bird, Archaeopteryx. Which of its characteristics were bird traits? Which characteristics were reptile traits?

- Bird: beak, wings, feathers - Reptile: teeth, claws, reptilian tail

Describe the fossils of Opabinia and its lifestyle, based on its body parts.

- Broad flat back: lived higher in the water - Had 5 eyes with a proboscis underneath

Identify seven characteristics that are unique to mammals.

- Hair - Mammory Glands - Diaphragm - Specialized teeth - 3 tiny middle ear bones - Lower jaw made from one bone - Special type of joint that connects the lower jaw to the upper jaw

Describe the echidna and its lifestyle

- Has hair, keeps it warm, also a defense, strong claws, beak-like snout, long and sticky tongue - eats grubs, ant, termites - Able to climb trees, lays eggs

Describe the basic body plan of a trilobite. What changes in this basic body plan allowed trilobites to occupy different ecological niches?

- Head, middle, tail - Made in different shapes and sizes so they could live in different places

Compare the eyes found in trilobite that were hunters and trilobites that were prey.

- Hunters: complex eyes, detailed pictures, sophisticated vision - Prey: more than 5000 lenses, sensitive to movement, extend around head, 360 view

6. Since ground-running dinosaurs could not fly, what are other possibilities for the use of their feathers?

- Insulation - Attracting mates - Hiding from predators - Insulating eggs

Describe the advantages of an internal skeleton versus an external skeleton.

- Internal: can grow large and move easily,vertebrae - External: it can provide defense against predators, Well protected, can live in different environments

Which group of ground-running dinosaurs had feathers?

Theropods

Why were fractal animals an evolutionary dead end?

They were immobile, simple and incapable of evolving.

Using synchrotron X-ray tomography, what did Professor Philip Donoghue learn about fossilized Markuelia embryos from South China?

Tiny ocean worm. First digestive system in an animal. From mouth to anus.

. Describe a chromosome

In eukaryotes, nuclear DNA and protein form long structures called chromosomes. Each chromosome is a twisted, double strand of DNA.

What are synapsids?

Mammals and relatives of mammals.

complete digestive system evolved in other animal groups, including the ancestor of _____________________

Markuelia

What two mammal branches are eutherians?

Marsupials and Placental.

This giant dragonfly lived in the Carboniferous period when oxygen levels were extremely high.

Meganeura

Describe the process of meiosis.

Meiosis starts in diploid cells in sex organs. Diploid cells have two full sets of chromosomes--one from the organism's mother and one from its father. Meiosis separates the chromosomes into two complete but separate sets. But during the process, the original chromosomes that came from the parents are shuffled and dealt out randomly to the new cells being formed (recombination or shuffling). The new cells with only one set of chromosomes are called haploid cells. Then a male haploid cell (sperm in animals) joins with a female haploid cell (egg in animals) during fertilization to produce a new individual called a zygote. Because the zygote contains two full sets of chromosomes, it is diploid.

radial symmetry

can be divided in many ways, each yielding two mirror images.

The Red Queen hypothesis applies to all of these challenges and threats except

climate change

This odd Cambrian animal had five eyes, a long snout-like proboscis, flaps along the sides of its body, and a broad flat tail.

Opabinia

Sponges Lack _______________

Organs

What fossil evidence supports the idea that dinosaurs incubated their eggs?

Oviraptor lay over its nest of eggs, with its wings spread out similar to modern day birds.

Describe the body of a sponge

collections of simple cells that clumped together.

lets an animal eat and process multiple meals at the same time along the tubular digestive tract. Each processing step can be more efficient, since it is being handled by specialized organs such as stomachs and intestines.

complete digestive system

Animal Group: Jellies include

corals, sea anemones and jellyfish

sponges do not have a _____________________

digestive system

Where were Charnia fossils first found

in rocks from Charnwood Forest, Leicestershire, England.

This small Cambrian animal was the first animal to have a backbone. This animal may be the common ancestor of all modern-day vertebrates.

Pikaia

Which statement best describes the Red Queen hypothesis?

Populations have to constantly evolve to keep up with ever-evolving parasites and other challengers.

What caused the end of the "Golden Age of the Arthropods"?

Rain forests died back and oxygen in the atmosphere dropped.

"You have to run as fast as you can just to stay in place." This phrase is a simple way to explain the

Red Queen hypothesis

What are the advantages of having a head?

Sensory organs in the head. They can sense food sources and move toward them.

Describe the body and lifestyle of Kimberella.

Sluglike, with a snout to sort through things to eat on the ocean floor. singular muscular foot

Which type of cells can transmit mutations to offspring?

Sperm or egg cells can pass germ-line mutations on to offspring.

Describe the platypus and its lifestyle.

Swims, finds food in water, bill is a sensing device.

Archaeopteryx also had reptilian characteristics, including: (1) ______________________________, (2) _____________________________, and (3) ________________________________________________.

Teeth in the jaw, tiny claws, long bony tail

_______ _____________ _____________ is an excellent example of an evolutionary phenomenon known as adaptive radiation

The Cambrian Explosion

What happens if you separate a sponge into individual cells with a sieve?

The cells move and form clumps until eventually they form a miniature sponge.

What additional evidence has been discovered to support this relationship?

The discovery that theropods had a wishbone

What is unusual about the whiptail lizard found in west Texas?

The lizards are all female and reproduce asexually.

Which of these is a reproductive disadvantage for the whiptail lizards of west Texas?

The lizards are not able to adapt to changing environmental conditions.

What did Dr. Mary Droser conclude by comparing Funisia fossils to modern-day corals?

The size groupings of attachment structures are a sure sign of sexual reproduction.

What does the increasing size of the nasal cavity in mammal skulls indicate about their bodies?

Their body temperature was rising.

How many types of subunits (nucleotides) occur in DNA?

There are four types of nucleotides, each containing a different base: adenine (A), cytosine (C), thymine (T), guanine (G).

The similarities between Archaeopteryx and Deinonychus indicated that birds were related to which specific group of dinosaurs?

Theropods

What was significant about the Burgess Shale fossils?

These fossils include animals from all major animal groups alive today.

Why are the Burgess Shale fossils so unusual?

They are so thin, you can only seen them at a certain angle with light. Never happened before or again, not found anywhere else

What is the purpose of the protein collagen in sponges?

They bind the sponge together.

What can a colony of cells accomplish that a single-celled organism cannot?

They can collect more food, control their internal environment, and work efficiently as a team.

How didWiwaxia, ammonites and arthropods respond to big predators?

They created defenses to protect themselves

Compared to velvet worms, how are true arthropods better adapted for life on land?

They had external skeletons so they did not dry out and it allowed them to get bigger and get around without the support of water.

This early arthropods were an extremely successful group of animals. These were the first animals with eyes that could form detailed pictures. Their complex eyes had lenses that could focus.

Triolobites

This group was one of the first animal groups to move to land. The body has breathing holes along the side, which allow the animal to breathe air. However, the soft permeable skin loses water. Today, these animals live in moist tropical areas.

Velvet worms

Describe the fractal animals body plan, as seen in Fractofusus.

Very thin, self-similar branches, huge surface area Exactly the same on both sides. Grew identically every time.

How did Snowball Earth come to an end?

Volcanic eruptions punching through ice, put Carbon dioxide in the air. Produced a green house effect, trapping heat and melting the ice

This Cambrian animal was an early snail with an armored disc-shaped body. It had two rows of upright spines used as defense.

Wiwaxia

Describe the body of Aysheaia and its modern descendent, the velvet worm, Peripatus.

Worm with legs with tiny holes on body to breathe air, there was no exoskeleton

Based on the phylogenetic tree on page 67 in the textbook, does fossil evidence support the evolution of tetrapod limbs from lobe-finned fishes?

Yes, you are able to see the evolution of bone structure.

What are the "huge costs" of reproducing sexually?

You only pass on 50% of your genes.

Adaptive radiation

a relatively rapid evolutionary event in which a few common ancestors lead to the appearance of many diverse new forms of life. By the end of the Cambrian Explosion, all of the major animal phyla that still exist today had appeared, with the most advanced being the early vertebrate fish.

gastrovascular cavity

a simple digestive pouch with only one opening

Nevo's lizards underwent remarkable changes when they were moved from an old island where insects were the main food source to a new island with no other lizards, and significantly more vegetation. Describe the types of changes that occurred in the lizards found on Pod Mrčaru, with respect to: a. anatomical changes b. ecological changes c. behavioral changes

a. The lizards heads were bigger, their legs had become shorter, they became slower, and the digestive tract had developed new muscular rings that pinched off a section of the gut, forming a chamber. b. The lizards of Pod Mrcaru could get more energy from the plants that the ones on Pod Kopiste get from insects. That extra energy could support a bigger population of lizards per acre of island. On Pod Kopiste, the lizards defended patches of the island to protect their supply of insects. c. With a more abundant supply of food on Pod Mrcaru, however, the lizards stopped fighting with each other over territory.

How does the similar use of DNA explain the evolutionary relationship between all living things?

all living things make their DNA with the same four nucleotides and they all use DNA in the same way. If we had no genetic relationship to each other it would be very, very unlikely that we all used DNA in the same way.

Based on this tree, what is the closest relative to the frogs?

amniotes

Other tetrapods evolved adaptations for life on land that allowed them to be less dependent on water. In addition to a waterproof skin, these animals have eggs that do not need to be laid in water. The eggs themselves have a little "pond" of water inside a shell. These tetrapods are called the ________________________

amniotes

Modern tetrapods include:

amphibians, reptiles (including birds), and mammals

Tetrapods

animals with a backbone (vertebral column), four limbs, and a body that is modified for life on land.

Vertebrates

animals with backbones,member of the chordates, descended from animals similar to Pikaia

Invertebrates

animals without backbones

A lineage is a line of direct descent from an ancestor. Mammals are one lineage. Besides humans, what other animals belong to this lineage?

anything that is warm blooded with hair and that nurses their young is a mammal.

When Vrijenhoek studied topminnows in the streams of Sonora, which group of minnows was more infected with black-spot disease?

asexually reproducing minnows

If all living things have DNA made of the same nucleotide subunits, why are we different?

Differences in the sequence of the nucleotides makes individuals in a species different from each other, and even greater differences in nucleotide order make species different from each other.

Give an example of a neutral mutation and explain why it is neutral.

In Lynche's study on yeast, the vast majority of mutations he and his colleagues detected were neutral (or, in other words, the mutations had no effect on survival).

What happens during DNA replication?

the first thing the cell has to do is make a copy of its DNA. That process is called DNA replication. Now that there are two DNA copies, the cell divides, with one copy of the DNA going to each of the new cells.

Why have the velvet worms remained unchanged since they moved onto land 540 million years ago?

they are nocturnal and stay hidden in rotting logs, can't grow bigger, have to stay in damp environments to not dry out

Describe the Carboniferous plant fossils found in Crail, Scotland.

very large stumps up to 90 feet

What structures are found inside the fin of Tiktaalik?

inside the fin are Bones that compare to our shoulder, elbow, and wrist : it has an upper arm bone, it has a lower arm bone, it has forearm bones, it has a wrist, it has finger-like bones. It is a fin that is able to support the animal.

Describe the process of recombination.

it brings together alleles of different genes into new combinations and because the genes work together, these new combinations can have significant effects on phenotypes

Briefly describe the fish traits and the tetrapod traits of Acanthostega.

it had a fish-like tail and gills for breathing in the water; yet it had forelimbs with hand bones for walking on land

What was significant about the Acanthostega fossil that Clack found?

it had hand bones

How was the forelimb of Acanthostega different from the forelimb of Tiktaalik?

it had phalanges and Tiktaalik did not

How was the forelimb of Tiktaalik different from the forelimb of Eusthenopteron?

it had wrist bones that Eusthenopteron didn't have

Is this phylogenetic tree based on a hypothesis or a theory?

it is a well supported hypothesis for how six vertebrate species evolved from a common ancestor and a vast number of traits support the tree

Radial symmetry is found in some animals, such as

jellyfish and corals

Modern vertebrates include:

lampreys, sharks and rays, bony fishes (ray-finned and lobe-finned) and tetrapods.

Using the Red Queen hypothesis, you would predict that a population of asexually-reproducing animals would be __________ _________ to thrive in an environment with many bacterial and viral diseases than a population of sexually-reproducing animals.

less likely

Monotremes

mammals that lay shelled eggs

Describe Charnia

marine organism, lived in darkness, looked like a plant and was immobile.

This group of animals evolved hard shells made of calcium carbonate.

mollusks

Describe asexual reproduction.

offspring are produced by a single parent, so each offspring has a copy of DNA that is identical to that of its single parent. In these organisms genetic variation comes only from mutations.

How do sexually reproducing organisms prevent the continual doubling of their chromosome number?

organisms have to make special cells with half the regular chromosome number, yet containing one full set of genes. The process used to do this is called meiosis.

Marsupials

pouched mammals

Based on this tree, what is the closest relative to birds?

reptile

According to Vrijenhoek, which group of minnows had greater variation and thus a greater advantage against black-spot disease?

sexually reproducing minnows

The functions performed by organs in complex animals are performed by individual cells in ____________________

sponges

Lobe-fins include ____________________, ____________________, and ____________________.

tetrapods, coelacanths and lungfishes

What is phylogeny?

the evolutionary relationship of a group of organisms.

Describe Hallucigenia. What does the body of this animal reveal about its environment?

- 5 legs, sharp spines - Needed to protect itself from predators

What is the big advantage of placental reproduction?

- Babies are able to stand quickly, move away from predators. - Mother can defend it.

Acanthostega (365 mya)

all the homologies

List the seven specific ways mutations can alter the DNA.

-a point mutation changes a single base to another -a segment of DNA may be inserted into the middle of an existing sequence -a segment of DNA may be accidentally deleted -a segment of DNA may be accidentally duplicated -a segment of DNA may be inverted -chromosomes can be fused together -genes can be passed from one organism to another through horizontal gene transfer

Describe the basic structure of trilobite eyes.

-complex eyes that could form detailed pictures -lenses are derived from mineralized external skeleton. Made from rock

complete digestive system

A more efficient digestive system with two openings

Disadvantage for sexual reproduction

Advantage for asexual reproduction

Every individual can have offspring is a/an

Advantage for asexual reproduction

More efficient method of producing offspring is a/an

Advantage for asexual reproduction

Parents pass on 100% of their genes. This is a/an

Advantage for asexual reproduction

"Provides new genetic combinations to adapt quickly to changing conditions" is a/an

Advantage for sexual reproduction

Abundant genetic variation in offspring is a/an

Advantage for sexual reproduction

This enormous millipede was the first arthropod on land.

Arthropleura

This group of animals evolved hard exoskeletons made of chitin.

Arthropods

Sponges

As oceanic ecosystems became more complex and diverse, new invertebrate body plans and adaptations appeared. One of the earliest multicellular animal groups to appear was _________________ 600 million years ago

Based on what evidence did Dr. Mary Droser base her conclusion?

Attachment structures on fossils: same size occurring together

This Cambrian soft-bodied animal was almost identical to the velvet worms found in the tropics today.

Aysheaia

Why is a good theory superior to facts?

Because it organizes facts, changing them from a loose collection of details into a meaningful, well-supported picture.

Describe the body plan and lifestyle of sea scorpions (eurypterids).

Biggest arthropod ever, 2 and a half meters or 8 ft in length, pinchers behind head

How does the platypus find its food in the water?

Bill is a remote sensing device.

Which two groups of animals burn fuel to generate body heat?

Birds and mammals.

Describe the characteristics of Tiktaalik roseae fossils found on Ellesmere Island, Canada.

Bones connected to a flattened skull. 3 feet, (lobe-finned fish) from the late Devonian period, having many features to those of tetrapods (four-legged animals). The name means a freshwater fish related to true cod.

Describe the similarities between Archaeopteryx and Deinonychus.

Both had lightly built, hollow bones, had long arms, similar hip and shoulder bones.

Describe the similarities between Archaeopteryx and Compsognathus.

Both have 3 digits, hollow bones, and stood on 2 legs.

According to the fossil record, the only animals in the seas for millions of years were simple multicellular animals, such as sponges and corals. Then "suddenly", about 535- 525 million years ago, a wide variety of more complex animal groups appear in the fossil record. This sudden change in the fossil record is known as the

Cambrian Explosion

What are the advantages of having numerous body segments?

Can increase in size. Each segment could do a particular job.

Describe reproduction in the echidna.

Carries egg on underside until it develops spines, then deposits it in a burrow

Describe the body plan of Spriggina.

Clear bilateral symmetry. Head and tail.

What two groups of fishes are the closest relatives to tetrapods?

Coelacanths and lungfishes

What was the Earth and its atmosphere like at the time of the Carboniferous plant?

Continents grouped together, forests widespread, atmosphere was changing, more oxygen, the oxygen then was 35%

Give an example of a harmful mutation

Cystic fibrosis is the result of a harmful mutation to a gene that encodes a channel on the surfaces of cells, causing cells in the lung to fill with fluid.

The similarities between "Archaeopteryx" and "Compsognathus" indicated that birds were related to which brand of reptiles?

Dinosaurs

"Cannot adapt quickly to changing environment" is a/an

Disadvantage for asexual reproduction

Limited genetic variation in offspring is a/an

Disadvantage for asexual reproduction

"Less efficient method of producing offspring" is a/an

Disadvantage for sexual reproduction

Males cannot bear offspring. This is a/an

Disadvantage for sexual reproduction

Mating requires time, energy and effort. This is a/an

Disadvantage for sexual reproduction

What is a gene and what is its function?

Each chromosome is subdivided into functional regions called genes. Each chromosome contains thousands of genes, and each gene contains hundreds to thousands of nucleotides. Each gene determines the structure of one or more proteins. Each protein performs a specific function in the cell.

These animals were the largest known arthropids These top predators had large powerful pincers that were used to grasp prey.

Euryptends

From an evolutionary standpoint, sexually-reproducing organisms are always more successful at surviving in a given environment than asexually-reproducing organisms.

False

When an asexually-reproducing organism clones offspring, the offspring are always genetically identical to the parent. Organisms that reproduce by cloning have no mechanisms that allow for genetic changes into their DNA.

False

The fossils of Archaeopteryx had some characteristics of modern birds: (1) __________________ along the wing and (2) __________________ on the tail.

Feathers, feathers

What three problems had to be solved in order for animals to move onto land?

Find a way to breathe air, support themselves with aid of water, and prevent themselves from drying out

Describe the significance of the fossils found in the Ediacara Hills of southern Australia.

First evidence of mobility

What is significant about Funisia, the fossil organism studied by Dr. Mary Droser?

First evidence of sexual reproduction. It exchanged genetic material with others like it. Led to more genetic variations and evolution.

Based on Jenny Clack's research, which came first: fish moving onto land or fish developing forelimbs?

Fish developing forelimbs.

What is an allele?

For any gene, there can be different variations that we call alleles. Let's take a simplified example, using freckles. There is an allele that codes for freckles and an allele that codes for no freckles.

What tetrapod-like features did Tiktaalik have?

Front appendages could bend at the elbow and support the weight of its body

What fish-like features did Tiktaalik have?

Gills, fins, and scales

Describe Snowball Earth and the geological evidence for it.

Global Glaciation. Evidence is "dropped" rock, which can be found all over the earth.

This unusual Cambrian animal had a slender body with five pairs of walking legs. Two sets of long spines ran along the back of the animal, probably to protect it from predators.

Hallucigenia

Describe the body features of Tiktaalik.

Has scales, fins, a flat head

Describe reproduction in the wildebeest

In womb and live birth.

more than 97% of all animals are

Invertebrates

Give an example of a beneficial mutation and explain why it is beneficial.

It could provide resistance to diseases, or allow an organism to get more energy from its food

Why was the discovery of Tiktaalik roseae significant?

It is a transitional fossil - It is a fish that blurs the distinction between a fish and a land-living animal. telling us that this is a fish that can live in the shallows and even make short excursions on to land.

What does the Burgess Shale in the Canadian Rocky Mountains reveal about animal evolution?

It occurred rapidly during this time period, surge of great diversity

Why is Tiktaalik considered to be a transitional fossil?

It shares characteristics of both amphibians and primitive fish.

How does the platypus bill differ from a duck bill?

It's not hard, more rubbery.

What is the function of DNA?

Its job is to carry information between generations

Their bodies consist of two true tissue layers organized around the gastrovascular cavity A jelly-like substance separates the two tissue layers.

Jellies

_____________ are more complicated than sponges

Jellies

________________ have tentacles covered with stinging cells that are unique to this group and are used for defense and capturing prey.

Jellies

What are the advantages of mobility?

Move away from danger, move towards food.

Do all mutations occur at the same rate? Why or why not?

No, because different kinds of mutations have different mutation rates.

All dinosaurs died at the end of the Cretaceous Period, 65 mya. Is this a true statement or not? Explain your answer.

No, because reptiles and birds are from the dinosaurs lineage.

Can a mutation which occurs in a somatic cell be inherited?

No, because the lineage of cells produced from somatic mutations will end when we die.

Which of these is a reproductive advantage for the whiptail lizards of west Texas?

Offspring are clones of their parent.

Meganeura was a giant __________________ with a wingspan of _______ feet.

dragonfly, 3

bilateral symmetry

draw a line down the middle from head to tail, making equal right and left sides.

intracellular

each individual cell is responsible for taking in and breaking down its own nutrients.

Jellies

early animal group to appear about 580 million years ago

How is it possible to have more than two alleles for the same gene in a population?

ex. There are five possible forms (alleles) of a white shirt: sleeveless, short-sleeved, long-sleeved, polo shirt and a turtleneck. In this imaginary population of 1000 people, an individual can only have two white shirts but all five types of shirts are present in the population.

What are the advantages of having a tail (back end)?

excretion

How is a phenotype different from a genotype?

genotype (DNA): the actual alleles inherited from parents. phenotype: the physical manifestation of the alleles of an individual.

Symmetry in Animals

how many ways you can divide an animal in half and get "mirror" images

Eusthenopteron (385 mya)

humorous, radius, and ulna

Tiktaalik (375 mya)

humorous, radius, ulna, and wrist bones

What effect does recombination have on the offspring of sexually reproducing organisms?

if a new mutation arises in a father, for example, his child will carry his mutated version of the gene and another allele inherited from the mother. If the mutant allele is dominant, it will always alter the phenotype of a child that inherits it. (recessive alleles will not have any affect)