Bio 4B Final Exam

Cladogram of Amniotes * Subclades: Diapsids, Synapsids, Archosaurs, Lepidosaurs, Dinosaurs, Saurischians. * What extant lineages are included. * Which includes dinosaurs. * Extant lineages: * Examples (common names), i.e. turtles, birds, etc. * Position on the cladogram in terms of relative degree of rotation (which are sister groups, which are in a subclade together (i.e. Archosaurs and Lepidosaurs, Tuataras and Squamates(.

(Ignore pink circle, idk).

Know the process by which prokaryotes reproduce.

* Binary fission * 1-3 hour generation time * Doubles every generation; 2^n where n = generation time.

Know the Cladogram of chordates. * Know each lineage, the common names of the lineages, the derived trait present in each lineage which is not present in the earlier lineages, the general characteristics of each lineage, and the common name of the examples given.

* Cephalochordata: Lancelets - The only extant cephalochordate. - Only a few centimeters long. - Usually found buried in sand at the bottom of warm temperate and tropical seas. - Named for their bladelike shape. - Suspension feeders. * Urochordata: tunicates/sea squirts - Show all of their chordate features only during their larval stage, which may only last a few minutes. Metamorphosis from the larva to adult form involves the resorption of the tail and notochord and 90 degree rotation of the remaining organs. Adults draw in water through an incurrent siphon, filtering food particles. When attacked, tunicates shoot water through their excurrent siphon. * Myxini: Hagishes - Jawless vertebrates, cartilaginous skyll, reduced vertebrae and flexible rod of cartilage derived from the notochord, small brain, eyes, ears, a nasal opening, tooth-like formations in their mouths, marine; most are bottom-dwelling scavengers, produce slime to repel competitors and predators. * Petromyzontida: Lampreys - Jawless vertebrates, have a notochord and cartilaginous skeleton, inhabit various marine and freshwater habitats, some are parasites that feed by clamping their mouths onto a live fish, free-living species feed as larvae for several years and then mature, reproduce, and die within a few days. * Chondrichthyes - Skeleton composed primarily of cartilage, largest and most diverse group of chondrichthyans includes the sharks, rays, and skates. A second group is composed of a few dozen species of ratfishes, or chimaeras. The largest sharks are suspension feeders; most are carnivores. Have a short digestive tract with a spiral valve that increases surface area and slows the passage of food. Acute senses including sight, smell, and the ability to detect electrical fields from nearby animals. Sharks have a streamlined body and are swift swimmers. Dorsal fins function as stabilizers, and paired pectoral and pelvic fins are used for maneuvering. Continual swimming keeps sharks from sinking and maintains continuous flow of water over gills. Most Rays are bottom-dwellers that feed on molluscs and crustaceans. Flattened and have enlarged pectoral fins that function like water wings. Many have whip-like tails; in some species, the tail bears venomous barbs for defense. Shagreen often comes from rays. * Actinopterygii: Ray-finned fishes. - The fins, supported mainly by long, flexible rays, are modified for maneuvering, defense, and other functions. * Actinistia: Coelacanths - Were thought to be extinct because they were only known from fossils, but they're not extinct. * Dipnoi: Lungfishes - Though gills are the main organs for gas exchange, they can also surface to gulp air into their lungs. * Amphibia: - Most have gas exchange through their skin and lungs. While some amphibians are strictly aquatic or strictly terrestrial, most are found in damp habitats. Most have moist skin that complements the lungs in gas exchange. Fertilization is external in most species, and the eggs require a moist environment. In some species, males or females care for the eggs on their back, in their mouth, or in their stomach. * Reptilia - Have scales that create a waterproof barrier. Most lay shelled eggs on land. Have internal fertilization, before the eggshell is secreted. Most are ectothermic, absorbing external heat as the main source of body heat. Ectotherms regulate their body temp through behavioral adaptations. Birds are endothermic, capable of maintaining body temperature through metabolism (requires high metabolic rate) * Mammalia Derived Traits * Chordates: Complex centralized nervous system and brain. * Vertebrates: Vertebrae allows for more growth, a stronger structure, and more movement options. * Cyclostomes: Mouth isn't limited to filter feeding; cyclostomes can be predators and eat more food. * Gnathostomes: - Jaws: Hinged structure with teeth used to grip and slice food items. - Mineralized skeleton: bone is stronger. * Osteichthyans: swim bladder helps control bouyancy. * Lobe-fins: Pelvic and pectoral fins have rod-shaped bones surrounded by a thick layer of muscle, weight supporting. * Tetrapods: Limbs with digits -> walk, colonize land, allowed limbs to support weight. * Amniotic egg: Shell protects egg from dessication, a key terrestrial adaptation to life on land.

What animal lineages is/are dipoblastic and which is/are triploblastic?

* Diploblastic animals have two germ layers: ectoderm and endoderm. - EX: cnidarians and few other groups. * Triploblastic animals also have a third germ layer: an intervening mesoderm layer. - These include all bilaterians, i.e. include flatworms, arthropods, vertebrates, and others. * Radial symmetry: no front and back, or left and right. * Bilateral symmetry: A dorsal (top) side and a ventral (bottom) side. A left and right side. An anterior (front) and posterior (back) end.

Phloem sap: * Know the direction of movement. * Know the mechanism of movement.

* In angiosperms, sieve-tube elements are the conduits for translocation; sieve cells in gymnosperm. * Source -> Sink * Source: where sugar is produced. * Sink: wherever sugar is needed. Phloem flow hypothesis * Phloem sap moves through a sieve tube by bulk flow driven by positive pressure called pressure flow. * Phloem sap flows from sources, where pressure is high, to sinks, where pressure is low. * At the sink, sugar molecules diffuse from the phloem to sink tissues (unloading) and are followed by water. * Phloem pressure at sink remains low as water exits sieve tube cells.

What is maximum parsimony: what does it refer to and how is it applied?

* Less mutations = more simple = more likely. Systematics narrow possibilities until they find the simplest phylogeny - that in which there are the fewest homoplasies. Maximum parsimony - the simplest explanation is the most like. In this case, it is less likely that the same trait would evolve multiple times in separate lineages and more likely that the shared traits are ancestral. * Ex: What are the odds that two kids get the same mutation and didn't get it from either parent? * PIC: By adhering to the principle of maximum parsimony hypothesis A is more likely than hypotheses B or C because A shows fewer evolutionary events than B or C.

Lophotrochozoans * Know the traits that characterize this clade. * Know Platyhelminthes.: - Body shape - Body cavity - Two clades * In which clade are __________________. - Planarians - Cestodes - Trematodes * Know the blood fluke like cycle. * Know Cestode anatomy and mode of transmission.

* Some develop a lophophore (crown of ciliated tentacles) for feeding. * Some pass through a trochophore larval stage. * A few have neither feature. Platyhelminthes: * Body shape: dorsoventrally flattened body shape. * Body cavity: Acoelomates (no body cavity) * Flatworms are divided into two clades: Rhabditophora and Catenulida. * Planarians are Rhabditophorans. * Cestodes are Rhabditophorans. * Trematodes are Rhabditophorans. Trematodes parasitize a wide range of hosts. Trematodes that parasitize humans spend part of their lives in snail hosts. They evade their host's immune system by producing surface proteins that mimic their host (molecular camo) and release molecules that manipulate the host's immune system. Blood Fluke Life Cycle: 1. Larvae penetrate human host skin. 2. Larvae mature to adults in blood vessels near intestines. 3. Mature adults migrate to and reproduce in intestines. 4. Female resides within a groove of the male's body. 5. Fertilized eggs are shed in feces. 6. Eggs hatch into larvae which penetrate snail host. 7. Larvae mature in snail and reproduce asexually. 8. Asexually-produced larvae exit snail and swim to human. The primary host is the human, where sexual reproduction occurs. The secondary host is the snail, where only asexual reproduction occurs). Rhabditophore: Cestoda (Tapeworms) * Tapeworms are parasites of vertebrates. * Anatomy: - The scolex contains suckers and hooks for attaching to the host. - Proglottids are units that contain sex organs and form a ribbon behind the scolex. Pork Tapeworm Life Cycle 1. Pigs ingest food contaminated with eggs or gravid (fertilized, egg-filled) proglottids. 2. Eggs hatch, larvae migrate to muscle. 3. Larvae develop into cysts in muscle. 4. Human consumes undercooked muscle, ingesting live cysts. 5. Tapeworms emerge from cysts in human small intestine. 6. Tapeworm attaches to human small intestine by scolex. 7. Tapeworm absorbs nutrients through proglottids. 8. Eggs become fertilized within proglottids. 9. Gravid (containing fertilized eggs) proglottids break off and are released in feces.

Poriferans * Know their anatomy, including cell types. * Know their mode of nutrition. * What do they lack which is present in all Eumetazoans?

* Sponges are filter feeders: they capture food particles suspended in the water that passes through their body. Water is drawn through pores into a cavity called the spongocoel and out through an opening called the osculum. Choanocytes, flagellated collar cells, generate a water current through the sponge. Choanocytes also ingest suspended food via phagocytosis. Choanocytes are similar to choanoflagellates - animals are thought to have evolved from a choanoflagellate ancestor. * Sponges have no true tissues. Sponges consist of a gelatinous noncellular mesohyl layer between two cell layers (epidermis and choanocytes). Mesohyl contains amoebocytes and spicules. Amoebocytes are totipotent cells found moving through the mesohyl via pseudopods. Amoebocytes play roles in digestion and manufacture of skeletal fibers. Spicules are secretions that provide structure and protection. Depending on the species, they may be made of silica, calcium carbonate, and/or spongin. * Sponges have no true tissues.

Know the two major clades of Osteichthyes. - Formal name? - Common name? - In which are tetrapods?

* Two major clades of Osteichthyes: Actinoptyerygii (ray-finned fishes) Sarcopterygii (lobe-finned fishes) Tetrapods are lobe-finned, sarcopterygii.

Lophotrochozoa: Annelida * Know the two major clades. - In which clade are earthworms? - In which clade are leeches? * Know their means of locomotion. * Know their body cavity type. * Know their skeleton type. * Know their circulatory system type.

* Two major clades: 1. Errantia 2. Sedentaria - Sedentaria includes leeches and earthworms. * Locomotion by peristalsis - a series of wave like muscle contractions. * Body cavity: true coelom * Skeleton type: hydrostatic skeleton * Circulatory system type: closed circulatory system

Know the prokaryote cell structure.

* Unicellular; some colonial. * Size: 0.5-5 micrometers. * The three most common shapes are spheres (cocci), rods (bacilli), and spirals. * Prokaryote cells usually lack complex compartmentalization (organelles). Some prokaryotes do have specialized membranes that perform metabolic functions. These are usually infoldings of the plasma membrane.

Know the generalized plant life cycle.

.1. Male gametophyte (haploid) will release sperm and fertilize the egg housed in the female gametophyte (haploid). 2. Fertilization will produce a diploid zygote. 3. The zygote will grow into a diploid sporophyte that will produce haploid spores that will germinate into a haploid gametophyte. 4. The cycle will continue.

Echinodermata: * Know the five clades and examples of each. - Know distinguishing features of each. - Given an Echinoderm by common name (i.e. sea urchin), know which of the five major clades it belongs in. * Know the skeleton types. * Know general anatomy.

1. Asteroidea (sea stars) 2. Ophiuroidea (brittle stars) 3. Echinoidea (sea urchins) 4. Crinoidea (feather stars) 5. Holothuroidea (sea cucumbers) * A thin epidermis. * Endoskeleton of hard calcareous plates. * Have bilateral symmetry despite appearance of radial symmetry. Most adults appear to have radial symmetry with multiples of five, but their symmetry is not truly radial. Echinoderm larvae have visibly bilateral symmetry. Echinoderms have a unique water vascular system: a network of hydraulic canals branching into tube feet that function in locomotion and feeding. The sieve-like madreporite allows entry of seawater into the stone canal, which connects to the ring canal around the mouth. Ring canal connects to radial canals, which deliver water to tube feet. Asteroidea - Sea stars * Have multiple arms radiating from a central disk. * Feed on bivalves by prying them open with their tube feet, everting their stomach, and digesting their prey externally with digestive enzymes. * Can regrow lost arms. - Sea daisies * Armless species in the clade Asteroidea. * Only three species are known. * Live on submerged wood and absorb nutrients through a membrane that surrounds their body. Ophiuroidea - Brittle stars have a distinct central disk and long, flexible arms that they use for movement. - Some species are suspension feeders, while others are predators or scavengers. Echinoidea - Neither has arms but both have five rows of tube feet. Sea urchins also use their spines for locomotion and protection. Sea urchins feed on seaweed using a jaw-like structure (Aristotle's lantern) on their underside. Sand dollars are flat disks. Crinoidea - Sea lilies live attached to the substrate by a stalk. Feather stars can crawl using long, flexible arms. Both use their arms in suspension feeding. Holothuroidea - Lack spines, have a very reduced endoskeleton, do not look much like other echinoderms, have five rows of tube feet (some of these are developed as feeding tentacles).

Name the fungal divisions and know their major differences. * Which has flagellated spores? * Which produce conidia? What are conidia? * Which produces the "mushroom" that is most familiar to us? * Which produces spores within elongated sacs (also called cups)? * Which produces the zygosporangia? * To which division do/does _________ belong? - Bread mold - Most edible "mushrooms" - Penicillium - Various molds of blue cheese - The fungal disease that threatens amphibian species - Mycorrhizae

1. Basidiomycota: produces the "mushroom" (aka the basidiocarp) 2. Ascomycota: produces conidia, asexually produced spores of Ascomycota. Also produces the ascus, a cup-shaped structure where karyogamy occurs, forming the zygote. 3. Glomeromycota 4. Zygomycota: produces zygosporangia, the tough, dark protective covering that the heterokaryotic cell develops after plasmogamy, and where karyogamy occurs. 5. Chytridiomycota: has flagellated spores called zoospores. Two of the features that distinguish amongst the five divisions are: * Differences in the structures in which the zygotes are formed. * Differences in their spore-producing structures. Bread mold belongs to Zygomycota. Most edible mushrooms belong to Basidiomycota. Penicillium belongs to Ascomycota. Various molds of blue cheese belong to Ascomycota. The fungal disease that threatens amphibian species belongs to Chytridiomycota. Mycorrhizae belongs to: * Arbuscular mycorrhizal fungi: Glomeromycota. * Ectomycorrhizal fungi: 1. Basidiomycota 2. Ascomycota 3. Zygomycota

Know the three embryonic tissue layers and what tissues develop from each of them.

1. Ectoderm - the resulting outer layer is the ectoderm, which gives rise to tissues that form the dermal and nervous system organs. 2. Endoderm - the inner layer is the endoderm. The tissues of the endoderm develop into the digestive tract (stomach and intestines) and many accessory digestive organs, i.e. the liver. 3. Mesoderm - becomes the muscle layer and most other organs between the endo and ectoderm layers.

Know the Eukaryote super groups and the one in which Fungi belong. What other multicellular lineage is in this same super group?

1. Excavata 2. "SAR" clade 3. Archaeplastida 4. Unikonta Fungi are in the Unikonta supergroup. Unikonta is comprised of two major clades: Amoebozoans and Opisthokonts. Fungi are Opisthokonts, which is a major clade including Fungi and Animals (Metazoa), both lineages are multicellular.

Know the four derived traits of chordates.

1. Have a muscular, post-anal tail 2. Have a dorsal, hollow nerve chord 3. Have a notochord 4. Have pharyngeal gill-slits or clefts

Know the mechanisms of evolution.

1. Natural Selection: Offspring who inherit favorable traits will have better survival and reproductive success than offspring without such traits. Over time, those traits become more common in the population. * This is the most common mechanism. * This is the only mechanism of adaptive evolution (results in adaptations being common in the population). 2. Mutation: Introducing new alleles to a population results in a change in the gene pool. 3. Genetic drift: Changes to allele frequency due to random chance, not due to certain alleles being more favorable than others. * Most likely to occur in small populations. 4. Gene Flow (Migration): Changes to allele frequency due to individuals entering or leaving the population.

Know the flower anatomy and function of each structure.

A flower is a specialized shoot with up to four types of modified sporophylls (reproductive leaves) called floral organs, arranged in whorls. Sterile whorls function in attracting pollinators and protecting the young, developing flower. * Calyx - the outermost whorl, made of sterile sporophylls called sepals. It is usually green and protects the developing bud. * Corolla - the second whorl, made of sterile sporophylls called petals. It is usually brightly colored and attracts pollinators. Fertile whorls produce reproductive structures. * Androecium - the male reproductive whorl, made of fertile sporophylls called stamens. * Gynoecium - the female reproductive whorl, made of fertile sporophylls called carpels. Stamens A stamen is a microsporophyll with two parts: anther and filament. * Anthers are the Angiosperm microsporangia (where pollen is produced). * Filament elevates the anther to facilitate pollen transfer. Carpels A carpel is a megasporophyll with three parts: ovary, stigma, and style. * Ovary is where the ovules occur; ovules contain the megasporangia. * Stigma is sticky and collects pollen. * Style elevates the stigma to facilitate pollination. * The carpel is atop a flower stem called a receptacle. * Sometimes the receptacle grows around and encloses the ovary and can become part of the fruit (i.e. apple flowers).

What is convergent evolution and how does it explain similar traits?

A morphological indicator that different species share a common ancestor is a homology. Homologies (aka homologous structures): phenotypic and genetic similarities due to shared ancestry. * i.e. forearms of tetrapods. (four-legged animals) * The common ancestor of all tetrapods had the same arm bones and leg bones as found in its descendants. Caveat: it is not always true that a common morphology is due to having common ancestor. Homoplasies: Similarities NOT due to shared ancestry. Convergent evolution: the evolution of structures in different lineages due to similar environment and selection pressures. Analogies (aka analogous structures): Homoplasies due to convergent evolution. Ex: Two moles have similar morphologies due to their similar lifestyles. However, being a marsupial, the australian mole is more closely related to kangaroos and koala bears than to the Northern American mole. Being eutherian, the North American mole is more closely related to whales, humans, and cats than to the Australian mole.

Know the anatomy of phylogenic trees, i.e. nodes, out group, etc.

A phylogenetic tree is a way to visualize a hypothesis about evolutionary relationships. * Branch Points: Represents the divergence of two species. - AKA nodes. * Sister taxa: groups that share an immediate common ancestor. * Basal taxon: Diverges early in the history of a group; originates near the common ancestor of the group. Polytomy: A branch from which more than two groups emerge. Indicates that the evolutionary relationships are not clear. * A rooted tree shows the ancestor from which the others evolved. It is informative about relative evolutionary chronology, but does not show actual dates of divergence. * An unrooted tree may include two or more rooted trees, and does not imply known ancestor. It is less informative; common due to data gaps. In an unrooted tree, it is not known which branch is the oldest nor where they came from. * The organisms in question are separated from the outgroup. * An outgroup is a species or group of species that is closely related to the ingroup, but has diverged before the ingroup early on. The ingroup is our group of interest. By identifying the outgroup, we are defining the ingroup. Ex: When we are creating a phylogenetic tree of vertebrates, lancelets are the outgroup because they have no vertebrae. * Phylogenetic bracketing - a means of inferring traits based on an organism's position in a phylogenetic tree. * EX: Did dinosaurs have the trait of incubating and caring for eggs? - Birds sit on their eggs and give parental care to hatchlings. - Crocodilians do too. - Dinosaurs share a common ancestor with birds and crocodilians more recently than with reptiles (lizards and snakes). - It was hypothesized that the dinosaurs sat on their eggs and gave parental care. - A fossil nest was later found that supported that hypothesis.

Know the meaning of acclimatization.

Acclimatization: animal's physiological adjustment to changes in its external environment. EX:

Know what is adaptive radiation and why/how it occurs.

Adaptive radiation: Multiple species arise from one parental species. * Common in previously uninhabited areas with diverse terrain and habitats, i.e. - Newly formed volcanic islands. - After a mass extinction. Ex: On the Galapagos Islands, there are 13 finch species, all evolved from one ancestral species founder population.

Know the mechanisms of speciation.

Allopatric speciation: Geographic separation. * The gene pools of the two populations diverge due to mutations and natural selection in different environments. * After many generations of being reproductively isolated, the two populations lose their reproductive compatibility and are now separate species. * Ex: Two squirrels become different species after becoming separated on two different sides of a canyon. Sympatric speciation: Same location (no geographic separation). * Gene pools diverge despite being in the same location. * More common in plants than animals. * Ex: A mutation that results in a new flower color can result in reproductive isolation if the new flower color attracts a different pollinator. (Pink flowers attract bees, red flowers attract hummingbirds). * Sympratic speciation by polyploidy within a single species. - Polyploidy: More than two sets of chromosomes. - Polyploid: More than two sets (results from chromosome duplication without chromosome separation). * Sympratic speciation producing a successful hybrid from two different species. 1. Hybrid is infertile - Cannot make gametes because chromosomes cannot pair. 2. A mistake in mitosis doubles chromosomes. * Chromosome doubling produces homologous pairs. * Flower is able to produce gametes by mitosis.

Amniotic egg * Extraembryonic membrane names and functions. * Overall adaptive advantage of the amniotic egg.

Amniotes are named for the major derived character of the clade, the amniotic egg, which contains four extraembryonic membranes. The amniotic egg was a key adaptation to life on land. The amniotic eggs of most reptiles and some mammals have a shell which protects the egg from desiccation on land. Allantois: a disposal sac for certain metabolic wastes produced by the embryo. Chorion: exchanges gasses between the embryo and air (along with the allantois) Amnion: provides a fluid-filled cavity that protects the embryo against mechanical shock. Yolk sac: contains nutrient-rich yolk (other nutrients are in the albumen ("egg white").

Know regulators vs. conformers.

Animals that are regulators maintain a constant internal environment using internal mechanisms. Animals that are conformers allow internal conditions to change in accordance with external changes in the particular variable. NOTE: AN ORGANISM MAY BE DIFFERENT FOR DIFFERENT VARIABLES - THE SAME FISH MAY BE A THERMOCONFORMER AND AN OSMOREGULATOR.

Know the anatomy of flowering plant ovule. Know about flowering plant double fertilization: structures and their functions involved before fertilization and what becomes of them after fertilization.

As with Gymnosperm, the Angiosperm megasporangium is surrounded by a protective tissue called the integument. Together, the integument and the megasporangium make up the ovule. In Angiosperm (but not Gymnosperm), the ovule is enclosed within an ovary. There may be multiple ovules per ovary. As with the Gymnosperm, the Angiosperm megasporangium has a specialized cell called a megasporocyte which undergoes meiosis, producing 4 haploid megaspores and only one megaspore survives. The integument has an opening through which the microgametophyte (pollen) can bring sperm. The opening is called the micropyle. The surviving megaspore develops into the megagametophyte and is called an embryo sac. The haploid megagametophyte of an Angiosperm is more complex than that of a Gymnosperm. The Angiosperm megagametophyte has seven cells but 6 nuclei: * 3 antipodal cells, which produce chemicals that direct the growth of the pollen tube. * 2 synergids, which help the egg. * 1 egg * 1 central cell, which has two nuclei called polar nuclei. This cell plays a big role in the Angiosperm seed. The pollen grain reaches the sigma by pollinator or wind. The pollen tube elongates down the style to the ovule. After entering the micropyle of the integument, the sperm release two sperm. Each sperm fuses with a cell in double fertilization: * Fusion of haploid sperm and haploid egg produce a diploid zygote. * Fusion of haploid sperm and dikaryotic central cell produce triploid endosperm. The zygote develops into an embryo, which is the young sporophyte. The endosperm increases in size and becomes rich in carbs, protein, and/or oils (depending on the plant species). The integument hardens into the protective seed coat. The ovary wall develops into the fruit. The mature ovary wall is now called the pericarp. Fruit aids in dispersal. The seed coat aids in determining when germination should occur (correct light, water, temp conditions). The endosperm provides energy and nutrients: * That keeps the embryo alive until conditions are optimal for germination. Some can even remain alive for thousands of years!!! * For growth until the young sporophyte is large enough to be self-sufficient. The anthers of the flower are the Angiosperm microsporangia. Each microsporangium contains many microsporocytes that can divide by meiosis, each producing four microspores. Each microspore develops into a microgametophyte (pollen grain) of just two haploid cells: generative cell and tube cell. The generative cell is within the tube cell. * The tube cell elongates and becomes the pollen tube. * The generative cell gives rise to the two sperm by mitosis.

Know what is the biological species concept.

Biological species concept: Populations are of two different species if they cannot produce fertile offspring together.

What is the evolutionary origin of chloroplast?

Chloroplasts evolved by endosymbiosis where a photosynthetic cyanobacterium was engulfed by a heterotrophic Eukaryote. * The cyanobacterium was not digested but lived as an endosymbiont. The cyanobacterium endosymbiont evolved into a chloroplast. These first photosynthetic protists evolved into red and green algae.

Which protist group most recently shares a common ancestor with animals and what is the evidence for this?

Choanoflagellates share a common ancestor with animals more recently than any other protist. Evidence that choanoflagellates are closely related to animals: * Anatomical similarities: Choanoflagellates are similar to a type of animal cell called choanocytes (collar cells), found in a diversity of animals, including sponges, jellyfish, flatworms, and echinoderms. Molecular similarities: DNA sequence evidence and the presence of certain genes also support that hypothesis that choanoflagellates and animals are sister groups, i.e. genes for multicellularity.

What is circadian rhythm and what is an example?

Circadian Rhythm: Cyclical physiological changes that occur roughly every 24 hours. EX: Melatonin is produced more at night and body temp drops at night. (Can be messed up by jet lag)

Paraphyletic, polyphyletic, and monophyletic trees: * Know how to distinguish them. * Know which is the only relevant tree and why.

Clade: a group of species that includes an ancestral species and all its descendants. * A valid clade is monophyletic- it consists of the ancestor species and all its descendants. * A paraphyletic group contains its most recent common ancestor but does not contain all the descendants of that ancestor. These are usually a result of missing information i.e., if species "G" had not yet been discovered. * A polyphyletic group is one whose members' last common ancestor is not a member of the group; grouping includes distantly related species but does not include their most recent common ancestor. These are also a result of missing information, i.e., if species, E, F, and G has not yet been discovered but species D does not share certain traits with A, B, and C.

Cnidarians * Know their anatomy - name, structure, and function of each body part. * Know the two major clades and their body forms.

Cnidarians are diploblastic - they have two tissue layers. Between the two tissue layers is mesoglea - a noncellular gelatinous layer. Cnidarians have a radial body plan with a single opening function as both mouth and anus. The body cavity, called a coelenteron, is a gastrovascular cavity; it serves both digestive and circulatory functions. There are two variations on the body plan: the sessile polyp and motile medusa. A polyp adheres to the substrate by the aboral end of its body. A medusa has a bell-shaped body with its mouth on the underside. Medusa do not attach to the substrate but move freely. Some cnidarians will possess both forms at different life stages; some only have one form. Cnidarians are carnivores that use tentacles to capture prey. The tentacles are armed with cnidocytes, unique cells that function in defense and capture of prey. Nematocysts are specialized organelles within cnidocytes that eject a barbed stinging thread. The stinging thread may release a toxin into the prey, immobilizing it. Clade Cnidaria diverged into two major clades: Medusozoa and Anthozoa * Anthozoa occur only as polyps. * Medusozoa includes medusa species as well as polyp species.

Variations on flower anatomy: complete, incomplete, perfect, imperfect.

Complete flowers - Flowers that have all four organs. Incomplete flowers - Flowers lacking one or more organ. Perfect flowers - have male and female reproductive parts (aka monecious flowers). Imperfect - either male or female; not both (aka dioecous flowers)

Structure and function of: * Plant cuticle * Plant stomata * Plant spore * Vascular tissues

Cuticle: a waxy covering of the epidermis (outer tissue) prevents dessication of vegetative structures by providing waterproofing. Stomata: Specialized openings of the epidermis that allow for gas exchange between the outside air and the plant, which is otherwise blocked by the cuticle. Stomata can close to prevent water loss and open to allow gas exchange. A plant spore is a haploid cell that disperses from the parent plant and develops into multicellular haploid plants (in primitive plants) or plant structures (in more modern plants). A spore is coated with sporopollenin. Sporopollenin is a protein coat that prevents dessication of spores while awaiting the arrival of water. After being released from the parent plant, spores can survive without water until water becomes available for germination. Vascular tissue: not all plants have it. Vascular tissue allows plants to be large, grow leaves, tall stems, and deep roots.

Mammals * Derived characters? * Three lineages and how they differ from each other and where they are found (what continents).

Derived Characters * Mammary glands, which produce milk. * Hair and a fat layer under the skin for insulation. * Efficient kidneys and large intestine, which conserve water from wastes. * Endothermy (requires high metabolic rate) * Efficient respiratory and circulatory systems. * A large brain-to-body-size ratio * Extensive parental care. * Differentiated teeth. Three Lineages 1. Monotremes: small group of egg-laying mammals consisting of echidnas and the platypus. Females lack nipples and secrete milk from glands on their bellies; the baby sucks milk from the mothers fur. 2. Marsupials: the marsupial embryo develops within the mother's uterus and is nourished by the placenta. The marsupial is born very early in its development. It completes its embryonic development while nursing in a maternal pouch called a marsupium. Marsupials include opposums, kangaroos, and koalas. 3. Eutherians: commonly called placental mammals because their placentas are more complex than those of marsupials. Eutherians have a longer pregnancy than marsupials. Young eutherians complete their embryonic development within the uterus, joined to their mother by the placenta, which provides an intimate and long-lasting association between the mother and her developing young. Marsupials arose during the Mesozoic, when there were land bridges connecting the continents. Marsupials were on every continent. Drifting apart of continents made it difficult for the newly arrived placental eutherians in what is now central Asia to disperse much onto other continents. South America and Australia became isolated. Australia's isolation prevented eutherians from reaching Australia, allowing marsupials to dominate on Australia. South America was isolated for while as well before connecting with North America.

Ecdyosozoans * What trait unites them? * For Nematoda, know: - Common name - Trichinella * Mode of transmission * Name of disease - Caenorhabditis elegans * Why it's well-known

Ecdysozoans are covered by a tough coat called a cuticle. The cuticle often includes or is made entirely of the complex polysaccharide, chitin. The cuticle is shed or molted through a process called ecdysis. Nematodes: - Common name: Roundworms - Trichinella spiralis is a parasite that can be acquired by humans from undercooked pork. Undercooked pork may contain encysted larvae. Larvae emerge from dormancy by action of digestive liquids and mature in the mucosa lining in the small intestine. Sexual reproduction produces larvae within the small intestine. Larvae migrate to muscle and form cysts. Causes trichinosis - cysts of Trichinella spiralis. - Caenorhabditis elegans: a tiny soil nematode (around 1 mm long) that has become a model research organism. Studies using C. elegans include: * Programmed cell death processes. * Cell division * Gene regulation * Aging

What is fungi's mode of obtaining energy and nutrition?

Fungi are heterotrophs that release enzymes to the outside and then absorb nutrients from the "digested" material.

Know the general fungal anatomy: cell wall material, hyphae, mycelium.

Fungi have cell walls that contain the complex polysaccharide, chitin. Two main growth forms of fungi exhist: * Filamentous fungi have a body of string-like multicellular structures called hyphae. * Filamentous fungi consist of mycelia (single = mycelium) - networks of branched hyphae that extend through the medium that provides a food source (the nutritional substrate: soil, wood, host tissue). Two types of hyphae: some fungal species have septate hyphae while others have coenocytic hyphae. Septate hyphae: * Hyphal growth by mitosis and cytokinesis. * The fungal cell wall between daughter cells has a pore - and opening that allows cytoplasmic elements (even nuclei) to pass between cells. Coenocytic hyphae: * Hyphal growth by mitosis but not cytokinesis. * Rather than resulting in daughter cells, mitosis creates a mulinucleate cell that elongates.

Stomatal opening and closing: * Mechanism of opening and closing * Environmental conditions that would cause opening or closing

Guard cells turgid: stoma open Guard cells flaccid: stoma close When would they be open? * C3 and C4 plants: during the day. * CAM plants: at night When would they be closed? * C3 and C4 plants: at night * CAM plants: during the day All plants: when the hazards of water loss outweigh the benefits of allowing CO2 to diffuse in: * Hot * Windy * Dry * High CO2

Know the extant plant divisions and which do and don't _________. * Have dominant gametophyte generations. * Have dominant sporophyte generations. * Disperse by spores. * Require water for sperm to reach the egg. * Have vascular tissue. * Disperse by seeds. * Produce by pollen. * Produce flowers.

Hepatophyta: * Dominant gametophyte generation, disperse by spores, require water for sperm to reach the egg, no vascular tissue. Bryophyta: Dominant gametophyte generation, disperse by spores, require water for sperm to reach the egg, no vascular tissue. Anthocerotophyta: Dominant gametophyte generation, disperse by spores, require water for sperm to reach the egg, no vascular tissue. Lycophyta: Dominant sporophyte generation, disperse by spores, require water for sperm to reach the egg, has vascular tissue. Monilophyta: Dominant sporophyte generation, disperse by spores, require water for sperm to reach the egg, has vascular tissue. Gymnosperm: Dominant sporophyte generation, disperses by spores, produces pollen, does not require water for sperm to reach egg, has vascular tissue, disperses by seeds. Anthophyta (Angiosperm): Dominant sporophyte generation, disperses by spores, produces pollen, does not require water for sperm to reach egg, has vascular tissue, disperses by seeds, produces flowers.

Know the meaning of homeostasis and examples.

Homeostasis: the maintenance of internal balance. * Using homeostasis, animals maintain a "steady state" - a relatively constant internal environment. EX: River otter uses homeostasis to maintain a constant body temperature even as the ambient temperature fluctuates. Homeostasis can be used to maintain a constant internal level of temperature, salinity, water, blood sugar, and other variables as well. Set point: The ideal level of the variable. EX: 37 degrees is the set point of human body temperature. Ambient temperature changes above or below 37 degrees trigger physiological mechanisms that maintain the set point body temperature.

What is a mixotroph?

In addition to the usual eukaryotic organelles, some have organelles not found in multicellular eukaryotes. Protists have diverse nutrtional modes, including: * Photoautotrophs, which contain chloroplasts and are photosynthetic. * Chemoheterotrophs, which absorb organic molecules or ingest larger food particles. * Mixotrophs (photoheterotrophs), which combine photosynthesis and heterotrophic nutrition.

Membrane Potential of Plants * Ions involved. * Membrane active transport involved.

In plants, membrane potential is established through pumping H+ by proton pumps. Active transport: carried out my membrane proteins that transports the substance from the lower concentration to the higher concentration. Protons diffuse down concentration and electrical gradient, making the diffusion faster, and giving stronger energy due to the double-up on the two gradients.

Know the difference between protostome and deuterostome development. * Give examples of each.

In triploblastic animals, the archenteron becomes the alimentary canal (digestive tract). * There are two archenteron openings: the blastopore and the second opening. These openings become the two openings of the alimentary canal: the mouth and anus. Triploblastic animals can be categorized as having protostome development or deuterostome development. * Protostomes: the blastopore becomes the mouth. - EX: molluscs and annelids * Deuterostomes: the blastopore becomes the anus. - EX: echinoderms and chordates In protostome development, cleavage is spiral. * Spiral cleavage - planes of cell division are diagonal to the vertical axis of the embryo. In deuterostome development, cleavage is radial. * Radial cleavage - planes of cell division are either parallel or perpendicular to the vertical axis of the embryo. In protostome development, the spiral cleavage is determinate - the developmental fate of cells is determined early on. In deuterostome development, the radial cleavage is indeterminate - each cell in the early stages of cleavage retains the capacity to develop into a complete embryo. Indeterminate cleavage makes possible identical twins, and embryonic stem cells.

What is the evolutionary origin of mitochondria?

Mitochondria evolved before chloroplasts; each from endosymbiosis. Mitochondria evolved by endosymbiosis where a proteobacterium was engulfed by a heterotrophic pre-Eukaryote of archael lineage. The proteobacterium was not digested but lived as an endosymbiont. The endosymbiont provided ATP via cellular respiration and the host provided nutrients and protection. The endosymbiont evolved into mitochondria.

Lophotrochozoa: Mollusca * Typical body plan * Main parts - name, structure and function of each. * Four major classes and given examples.

Molluscs are soft-bodied (no skeleton) animals, but most are protected by a calcium carbonate shell. All molluscs have a similar body plan with three main parts. * Muscular foot - locomotion and anchorage. * Visceral mass - contains organs. * Mantle - secretes shell. Most have an open circulatory system. Four major classes of molluscs: 1. Bivalvia (EX: clams, oysters, mussels) 2. Polyplacophora (chitons) 3. Gastropoda (snails and slugs) 4. Cephalopoda (squids, octopuses, cuttlefish, and chambered nautiluses)

Know the noticeable external anatomical differences between Eudicots and Monocots. * Leaf venation * Number of floral parts * Root structure

Monocots have parrallel veins and floral organs that are in multiples of three. Monocots have fibrous roots (no main root). Eudicots have net-like veins and floral organs that are in multiples of four or five. Eudicots have a main root (taproot).

Internal anatomical differences between Eudicots and Monocots. * Stem - Cortex and pith - Vascular bundle arrangement * Leaves - Mesophyll type(s) - Stomata location

Monocots: *Stems: Vascular tissues are scattered. No cortex nor pith. * Leafs: No adaxial and abaxial distinction in mesophyll structure. Stomata is on both surfaces equally. Largish midvein and smaller (but not tiny) vascular bundles otherwise which are evenly spaced. Eudicots: *Stems: Vascular tissues are arranged in a ring. Have a cortex and pith. * Leafs: - Palisade parenchyma: * Adaxial (upper) portion of the eudicot leaf. * Allows maximum sun absorption throughout the leaf. - Spongy mesophyll * Abaxial (lower) portion of the eudicot leaf. Stomata is mostly on the abaxial epidermis, opening to an airspace in the spongy mesophyll. Very large midvein and rather small vascular bundle branches that are not very evenly spaced.

Amphibians What are their general characteristics? What are the major groups? * Formal name and common name? * General characteristics?

Most amphibians have gas exchange through their skin and lungs. Amphibian means "both ways of life", referring to the metamorphosis of an aquatic larva into a terrestrial adult. Urodela, "tailed ones" (Salamanders) * Some are aquatic, but others live on land as adults or throughout life. * Paedomorphosis, the retention of juvenile features in sexually mature organisms, is common in aquatic salamanders. Anura, "tail-less ones" (Frogs) * Frogs (Anura) lack tails and have powerful hind legs for locomotion on land. * Frogs with leathery skin are called "toads". Apoda, "legless ones" (Caecilians) * Caecilians (Apoda) are legless, are nearly blind, and resemble earthworms. * The absence of legs is a secondary adaptation.

Know the stages of animal embryonic development: names and descriptions.

Most animals reproduce sexually, with the diploid stage usually dominating the life cycle. Flagellated sperm fertilizes a (usually) non-motile egg. Zygote undergoes a rapid cell division and stages that result in different layers of embryonic tissues. 1. Zygote undergoes a series of mitotic divisions called cleavage. 2. After 3 mitotic divisions, the 8-cell stage; 3. 16 cells (called a morula and is still a solid mass) * First couple of divisions, cells are still totipotent (can form any tissue, even placental). 4. At over 100 cells, the ball becomes hollow and is called a blastula. Each cell is a blastomere. The hollow interior is the blastocoel. * Blastomeres are pluripotent (can give rise to most cell types). 5. Gastrulation occurs in most animals - the hollow ball of cells folds inward, into the blastocoel, forming the gastrula. 6. From gastrulation, three germ layers (early tissue layers) can develop, the first two to form being the endoderm and ectoderm. The two germ layers are separated by the blastocoel, a fluid-filled cavity. The pouch formed by gastrulation is the archenteron and the opening is the blastopore.

Body cavities * What distinguishes acoelomates, pseudocoleomates, and coelomates. * Examples of each.

Most triploblastic animals possess a body cavity, which may contain organs, air or just water, depending on the phylum. There are three variations on the body cavity: * A coelom is also known as a "true" body cavity. It is a body cavity surrounded by and formed from mesoderm. * EX: annelids (earthworms) and chordates (humans). * A pseudocolom is a body cavity derived from the mesoderm and endoderm * EX: nematodes (roundworms). * Acoelomates are triploblastic animals that lack a body cavity, i.e. planarians (flatworms).

What is mycorrhizae and how do arbuscular mycorrhizae (aka endomycorrhizae) differ from ectomycorrhizae?

Mycorrhizae: A mutualistic symbiosis association between a plant and a fungus. * Symbiosis: Living together. * Refers to an association between different species. Mutualistic symbiosis: refers to a symbiosis where members of the association all benefit. The fungus benefits by receiving carbs from the plant. The plant benefits from the fungus' ability to reach soil nutrients and water far from the plant's roots. Two main types of mycorrhizae: Ectomycorrhizae and Arbuscular Mycorrhizae * Ectomycorrhizal fungal species are always ectomycorrhizal; arbuscular mycorrhizal fungi are always arbuscular. * Ectomycorrhizal fungi cover plant root tips and grow between root cells. The mycelial covering on the root tip is called a mantle. * Arbuscular mycorrhizal fungi penetrate cells of plant root tips and form branched structures called arbuscules within the plant cells. The type of fungus with which a plant associates is species specific. EX: blueberry bushes only form ectomycorrhizal associations, never arbuscular. EX: grass plants (all species) only form arbuscular mycorrhizal associations, never ectomycorrhizal. All arbuscular mycorrhizal fungi (a type of plant mutualist) are in the Division Glomeromycota. Three divisions include species that are ectomycorrhizal fungi. 1. Basidiomycota 2. Ascomycota 3. Zygomycota

Know the three ways in which natural selection can alter a population.

Natural selection can alter variation in a population in three ways: 1. Directional Selection: Occurs when individuals with traits on one side of the mean in their population survive better or reproduce more. Ex: Grey mice survive better/reproduce more. 2. Stabilizing Selection: A type of natural selection in which genetic diversity decreases as the population stabilizes on a particular trait valve. Ex: Mice stabilize on being light grey (in between). 3. Disruptive Selection: A mode of natural selection in which extreme values for a trait are favored over intermediate values. Ex: Only white mice or dark grey mice, no light grey.

Compare negative feedback and positive feedback and know examples of each.

Negative feedback: Conditions return to the set point Events of negative feedback: * Stimulus: A fluctuation in the variable above or below the set point. * Sensor: Detects the stimulus * Response: Physiological activity returns the variable to the set point. * Stimulus: Variable reached set point. * Sensor: Detects the stimulus. * Response: Physiological activity ceases to alter the variable because the set point has been reached. EX: Temp regulation of a building Positive feedback: Refers to mechanisms that push a variable further and further away from the starting point. EX: Childbirth * During childbirth, positive feedback causes uterine contractions to increase in strength. * During childbirth, the pressure of the baby's head against sensors near the opening of the mother's uterus stimulates the uterus to contract. * These contractions result in greater pressure against the opening of the uterus. * Greater pressure causes stronger contractions. * Stronger contractions cause even greater pressure. * Contractions get stronger and pressure gets stronger. * On and on.... until the baby is born.

Bulk water flow: * Direction of movement * Mechanism of movement

Negative water potential continues to drive movement once water (and minerals) are inside the root; the water potential of the soil is much higher than the water potential of the root, and the water potential of the cortex is much higher than the water potential of the stele. Once water has been absorbed by a root hair, it moves through the ground tissue through one of three possible routes before entering the plant's xylem- the symplast: in this pathway, water and minerals move from the cytoplasm of one cell in to the next, via plasmodesmata that physically joins different plant cells, until eventually reaching the xylem. the transmembrane pathway: in this pathway, water moves through water channels present in the plant cell plasma membranes, from one cell to the next, until eventually reaching the xylem. the apoplast: in this pathway, water and dissolved minerals never move through a cell's plasma membrane but instead travel through the porous cell walls that surround plant cells. The endodermis acts as a controlled entry to the vascular cylinder (stele). Once inside, the water and minerals move up the xylem and to the leaves of the plant as xylem sap. The water will evaporate out through the stoma while the minerals will be retained in the plant cells. The endodermis serves as a checkpoint for materials entering the root's vascular system. A waxy substance called suberin is present on the walls of the endodermal cells. This waxy region, known as the Casparian strip, forces water and solutes to cross the plasma membranes of endodermal cells instead of slipping between the cells and not getting filtered. This ensures that only materials required by the root pass through the endodermis, while toxic substances and pathogens are generally excluded.

What is "secondary endosymbiosis"?

On several occasions during eukaryotic evolution, red and green algae underwent secondary endosymbiosis, in which they were ingested by a heterotrophic eukaryote.

Of all the Supergroups combined, what proportion is comprised of Protists (approximately)?

Organisms in most eukaryotic lineages are protists. * PIC: All of the yellow-highlighted lineages to the left are protists.

Know the cell types- parenchyma, collenchyma, sclerenchyma. * Number of cell walls * Alive at maturity or not * Distinctive shapes or cell wall features * General functions and locations within a plant * Specific examples

Parenchyma: alive at maturity, primary cell wall only (no secondary), metabolically active. * Specific parenchyma: Chlorenchyma: photosynthetically active. Glandular cells: secrete a kind of excedate. Transfer cells: move materials from cell-to-cell. Storage cells: store stuff- water and/or sugar and/or starch. Pigmented cells: give color (i.e. flower petals) Epidermal cells: skin cells. Collenchyma: alive at maturity, primary cell wall only, cell wall is unevenly thickened, no chloroplasts, low metabolic activity, long, flexible - provide "plastic support" to petioles and young stems. Beneath the epidermis of petioles, young stems, and large leaf veins (i.e. celery string). Sclerenchyma cells: dead at maturity, secondary cell wall (thick), strong, lumen - empty space where cytoplasm was. * Types of sclerenchyma cells: - Fibers: long and flexible, support for mature stems. - Sclereids: cuboidal and inflexible. - Xylem: one of the vascular tissues, conducts water.

Know secondary growth. * Know the difference from primary growth. * Know the tissues involved. * Know the difference between lateral and apical meristem. * Know the difference between monocots and eudicots. * Know the meristem location, structure, and function: - Cork cambium - Vascular cambium * Structure and function of wood. * Structure and function of cork.

Primary plant body is new and fresh, getting longer. The secondary plant body is getting thicker and growing wood. Primary Stem Inner Tissue: Ground Tissue * Composed mostly of ground tissue. - Photosynthetic (outer) - Storage parenchyma - Sometimes includes collenchyma and/or schlerenchyma fibers (structure). * Cortex- interior to the stem epidermis of eudicots. * Pith the interior to the vascular ring of eudicots. * Vascular tissue arranged in vascular bundles. - Xylem tissue conducts water and minerals. - Phloem tissue conducts sugars. * Includes parenchyma cells - storage and maintaining conducting cells. * Includes sclerenchyma fibers - added strength. * Bundle arrangement differs between eudicots and monocots. * Xylem is to the inside of phloem. * Apical meristem: produces new stem, enables plant to grow taller. Secondary Growth: Vascular Cambium and Cork Cambium * Lateral Meristem: produces secondary growth, enables plant to grow in thickness. * Vascular cambium - lateral meristem that produces secondary vascular tissue, called secondary xylem and secondary phloem. * Cork cambium - lateral meristem that produces secondary dermal tissue, called the periderm. * Fusiform initials - the meristem cells of the vascular cambium which produce secondary vascular tissue. * Mitosis of the initials produce two cells. * One is another initial. * The other is xylem or phloem. * Secondary xylem - Wood is secondary xylem (heartwood) and new secondary xylem (sapwood). Produced to the inside of the vascular cambium. * Secondary phloem - secondary phloem is the inner layer of "bark", produced to the outside of the vascular cambium. * Periderm is cork cambium and cork. * Cork cambium is the lateral meristem that produces cork. Cork is infused with suberin (water and microbe-resistant). * "Bark" is secondary phloem, cork cambium, and cork. Only eudicots have secondary growth since only they have vascular cambium. Lenticels are openings in the cork that allow gas exchange (waxy suberin blocks it). Oxygen is needed for cellular respiration by living cells, i.e. cambium, phloem, and rays. Carbon dioxide is a waste product of cellular respiration. Phloem rays: store starch and help maintain a living connection between the vascular cambium and cork cambium. Xylem rays: storage and transport of water, nutrients, and non-structural carbs (NSC) laterally. Ray initials are cells of the vascular cambium that produce rays.

Know the three means of bacterial genetic recombination.

Prokaryotes produce offspring that are clones of parental cells. Populations that descend from one parent cell can still show genetic diversity. Prokaryotes have mutations and rapid reproduction. Additionally, genetic diversity is achieved through horizontal gene transfer (the movement of genes from one genome to another), and genetic recombination (three mechanisms). * Transformation - take up foreign DNA that is free-floating in the environment. Ex: Bacteria comes from person or animal. * Transduction - by bacteriophage (a virus that infects bacteria). * Conjugation - cell to cell exchange of DNA.

Are protists Eukaryotes or Prokaryotes?

Protists are unicellular Eukaryotes

Know the different types of reproductive barriers.

Reproductive barriers: Biological barriers that prevent two individuals from successfully producing fertile offspring. Prezygotic barriers: Barriers to producing a zygote. 1. Habitat isolation: Lack of opportunities to encounter each other. 2. Temporal isolation: Breeding at different times or seasons. 3. Behavioral isolation: Different courtship rituals. 4. Mechanical isolation: Physical incompatibility of reproductive parts (Some flowers can only be pollinated by hummingbirds with long, curved bills while others can only be pollinated by hummingbirds with short, straight bills). 5. Gametic isolation: Molecular incompatibility of eggs and sperm or pollen and stigma. Postzygotic barriers: Zygote is formed but offspring is not successful 1. Reduced hybrid viability: Hybrid development or survival impaired by interaction of parental genes. 2. Reduced hybrid fertility: Vigorous hybrids that cannot produce viable offspring (Mules are robust but sterile). 3. Hybrid breakdown: Viable and fertile hybrids with feeble or sterile offspring.

Know the general fungi life cycle.

Reproductive events involve the growth of spore-producing structures, i.e. a "mushroom". The cells in the fungal hyphae may be: * Haploid (one set of chromosomes) or * Heterokaryotic (two different haploid nuclei, one from each parent). The only diploid stage of the fungal life cycle is the zygote. * The zygote is the result of sexual reproduction. * The zygote is short-lived and quickly undergoes meiosis, producing spores (or producing haploid cells that produce spores). Therefore, there is no multicellular diploid stage. The events of the filamentious life cycle * Germination - Haploid hyphae start to grow from the haploid spore. Hyphae increase in length by mitosis. * Plasmogamy - Hyphae of two compatible mating types fuse such that they share cytoplasm. * Mating types are designated as + and - rather than male and female. * Mating types find each other by sexual signaling molecules called pheromones - signaling chemicals between individuals. * The result of plasmogamy is heterokaryotic hyphae which contains haploid nuclei from each parent. * Karyogamy - the fusion of the two different haploid nuclei into a diploid nucleus. A cell with a diploid nucleus is a zygote. * Meiosis - meiosis of the zygote produces haploid spores. Many filamentous fungi can reproduce asexually as well as sexually. Asexual reproduction involves making and dispersing colonal spores. Yeasts are unicellular fungi. They reproduce asexually by simple cell division and the pinching of "bud cells" from a parent cell. Yeast do not reproduce sexually. Some fungi can both grow as yeasts and as filamentous mycelia. As yeast, they reproduce asexually only. As filamentous fungi, they reproduce sexually or asexually.

Reptiles * Are they Diapsids or Synapsids? * General characteristics? * Examples?

Reptiles are diapsids. Have scales that create waterproof barrier. Most lay shelled eggs on land. Have internal fertilization, before the eggshell is secreted. Most are ectothermic, absorbing external heat as the main heat source of body heat. * Ectotherms regulate their body temp through behavioral adaptations. Birds are endothermic, capable of maintaining body temp through metabolism (requires high metabolic rate) Reptiles include turtles, crocodiles, dinosaurs, birds, lizards, snakes, etc. Diapsids: Having a pair of holes on each side of the skull behind the eye sockets through which muscles pass to attach to the jaw).

Know how secondary sex characteristics evolve.

Sexual selection may lead to secondary sex characteristics in animals. Secondary sex characteristics: traits presented in males only or females only. * Coloration, i.e. in many bird and fish species, males are more colorful than females. * Anatomy, i.e. elk males have antlers whereas females do not. * Behavior, i.e. male tree frogs and male mockingbirds make prolonged and complicated vocalizations to attract females.

What lineages are more closely related than others?

Sister taxa: Groups that share an immediate common ancestor. (Two siblings share a parent).

Describe the structure and function of capsules, the slime layer, flagella, pili, fimbriae, and endospore.

Some bacteria produce a layer external to the cell wall that can be identified with a specific staining procedure. The layer might be made of carbs or a combination of carbs and proteins. There are two types of external layers, both are identified using a capsule stain. Capsule * A solid layer. * Helps cells adhere to surfaces. * Helps cell evade phagocytosis by white blood cells, allowing infection to occur. Slime layer * Loosely organized, sticky. * Helps cell colonize surfaces. * Helps cell begin biofilm. - A thick, multi-layered aggregation of multiple bacterial species. - May create blockage in pipes. - May contaminate medical equipment. Fimbriae: Hair-like extensions that allow cells to stick to their substrate or other individuals in a colony (biofilm). Pili (or sex pili): Extensions longer and less numerous than fimbriae that allow prokaryotes to exchange DNA. Flagella: Allows motility via taxis. * Taxis: The ability to move toward or away from a stimulus. * Composed of a motor, hook, and filament of the protein flagellin. Many of the flagella's proteins are modified versions of proteins that perform other tasks in bacteria, such as secretion and ion transport. Flagella likely evolved as existing proteins were added to an ancestral secretory system. This is an example of exaptation, where existing structures take on new functions through descent with modification. Endospore: Formed as a means of surviving adverse conditions. * The cell copies its chromosome. * The cell forms a resistant protein coat. * The cell dehydrates and stops metabolism. * Can remain viable for centuries.

Know the general plant anatomy: location, structure, and function. * Stem anatomy - nodes, internodes, axils, axillary buds, stem apical meristem, root apical meristem. * Leaf anatomy - regular epidermal cells, trichomes, stomata, guard cells, petiole, sheathing leaf base. * Root anatomy: - General: epidermis, cortex, endodermis, stele, pericycle. - Differences between monocots and eudicots. * Cortex and pith * Vascular bundle arrangement * Root tip regions: - Three regions-location, functions, and differences from eachother. - Root hairs - structure, location, and function. - Root cap - structure, location, and function. * Epidermis: - Types of cells and function of each. - Wax layer - name of wax, name of layer, function.

Stem anatomy: * Nodes: Part of the stem, where the leaf attaches. * Internodes: Stem distance between nodes. * Leaf axil - Upper angle between leaf and stem; just above node. * Axillary bud: Meristem in leaf axil that gives rise to lateral stems (branches), thorns, or flowers. * Apical bud: meristem at tip of stem that produces new, longer stem. * Root apical meristem: Responsible for the growth of the root tissue below the ground. Leaf anatomy: * Regular epidermal cells: have no chloroplasts and secrete cutin (or wax). * Trichomes: non-ordinary epidermal cells, elongated epidermal cells (i.e. hairs). Protection from predators, dessication. * Stomata: stoma = stomatal pore + guard cell, plural = stomata, allow gas exchange but close to conserve water. * Guard cells: have chloroplasts and regulate stomatal opening. * Petiole: a stalk that joins a leaf to a stem (mini stem of branched plants). * Sheathing leaf base: No petiole/blade distinction. There are "leaves" growing up the stem like corn. Root anatomy: * Epidermis: dermal tissue but with NO cutin layer NOR guard cells (usually). * Cortex: Ground tissue, energy storage. * Endodermis: Innermost layer of the cortex (single layer of cells). Prevents some dissolved substances from entering the xylem by the Casparian strip (made of suberin, a wax). * Stele: Vascular tissue of the root, collectively. * Pericycle: Outermostlayer of the stele, develops into lateral roots (root branches). Monocots: have a pith and cortex, alternating xylem and phloem bundles surround a pith. Eudicots: have a cortex but no pith, xylem is central and surrounded by phloem bundles. Root tip regions * Region of maturation: oldest, root hairs are developed and functional (absorbing water and nutrients). * Region of elongation: Cells are elongating and starting to differentiate into specialized tissues. Causes the root tip to push further down/out into the soil. * Region of cell division: Mitosis is ocurring at the apical meristem. Each mitotic event produces new cells. (where root cap is found) Epidermis * Single external layer of parenchyma cells. Has a cuticle of cutin, sometimes wax secreted by epidermal cells. Cutin protects from dessication. * Covers primary plant body: green (non-woody) stems, leaves, non-woody roots. * Protection from infection, herbivores, and preventing water loss. * waterproof, anti-microbial.

Know what evolutionary adaptations distinguish the clades from eachother (the derived traits before each branch poit, i.e. true tissues, bilateral body plan, etc). For any given animal, know the Eumetazoan lineage in which it belongs.

The entire animal clade is Metazoa. * Sponges (Phylum Porifera) are basal animals. * Eumetazoa ("true animals") is a clade of animals with true tissues. * Basal Eumetazoans: - Have radial symmetry and are diploblastic (2 germ layers). - Include Ctenophore (comb jellies) and Cnidaria (jelly fish and sea anemones). * Bilaterians - Have bilateral symmetry and are triploblastic (3 germ layers). - Includes most animals. * Deuterostomia, Ecdysozoa, and Lophotrochozoa - The three major clades of bilaterian animals. All members have deuterostome development. - Deuterostomia includes: 1. Hemichordata (acorn worms): Share some characteristics with chordates, i.e. gill slits and a dorsal nerve chord. 2. Echinodermata (sea stars and relatives): no nerve chord nor gill slits - perhaps these traits were lost in this lineage. 3. Chordata: includes vertebrates (have a backbone) and invertebrate chordates. (The only lineage that contains vertebrates, although not all chordates are vertebrates). All Deuterostome development (though not all animals with deuterostome development are in the clade Deuterostomia). * Lophotrochozoa - a clade of bilaterian invertebrates. - Some have a feeding structure called a lophophore. * A lophophore is a mouth with a crown of ciliated tentacles that sweep in food. * Others go through a distinct developmental stage called the trochophore larva. - i.e. molluscs and annelids. - Not all members of this clade have both or either of these features. * Ecdysozoa: a clade of invertebrates that, as they grow, shed their exoskeletons through a process called ecdysis (molt). - The replacement of exoskeleton is secreted. * i.e. insect coverings and flexible nematode cuticle. - Includes nematodes, arthropods, and other phyla. - NOTE: Not all animals that molt are in this clade.

Mammals: Primates Derived characters? Which primates are included in Anthropoids, which in Hominoids, and which in Hominins? What species is Lucy?

The mammalian clade Primates includes lemurs, tarsiers, monkeys, and apes. Humans are members of the ape group. Derived Characters of Primates * Most primates have hands and feet adapted for grasping. * Flat nails instead of claws. * A large brain and short jaws. * Forward-looking eyes close together on the face, providing depth perception. * A fully opposable thumb (in monkeys and apes). Anthropoids = monkeys + hominoids Hominoids = nonhuman apes + humans Hominins = the several extinct "human-like" species as well as the extant Homo sapiens. Lucy is an adult female Australopithecus afarensis., a hominin.

Know the structure of the prokaryote genome.

The prokaryote genome has less DNA than the eukaryotic genome. Most of the genome consists of a circular chromosome located in the nucleoid region. Plasmids: smaller, extra rings of DNA in some bacteria. * May contain "extra", non-essential genes, i.e. antibiotic resistance. DNA replication * Some differences between prokaryotes and eukaryotes in DNA replication, transcription, and translation: primarily in the enzymes (i.e. polymerase) and ribosomes. * These differences allow people to use some antibiotics to inhibit bacterial growth without harming themselves.

Know the cell wall differences between Gram Positive and Gram Negative Bacteria.

The results of the Gram Stain procedure is that Gram Negative bacteria are pink while Gram Positive bacteria are purple. The difference in their color is due to differences in their cell wall structure. * Gram positive bacteria have a cell wall that is made of a thick layer of peptidoglycan (made of sugars and proteins). * Gram negative bacteria have a cell wall that is made of: - a thin peptidoglycan layer AND: - an outer phospholipid membrane that contains lipopolysaccharides, which can: * be toxic and prevent antibiotics from reaching the cell wall or other target molecules. Cell wall function: both types of cell walls maintain cell shape, protects the cell, and prevents bursting in a hypotonic environment.

What taxonomic value does the grouping together or "Protists" have, if any?

The term "Protist" has no taxonomic value - it simply refers to organisms that are unicellular eukaryotes.

Ecdysozoans: Tardigrada * Know their habitats * Know why they're well-known

They're found everywhere: from baren mountaintops, deep sea, mud volcanoes and their range extends from tropical rainforests to the Antarctic. Known to survive extreme conditions, i.e. extreme temperatures, extreme pressures (both high and low), air deprivation, radiation, dehydration, and starvation. Tardigrades have even survived exposure to outer space.

Know the difference between ancestral and derived traits and their relevance to constructing phylogenetic trees.

Traits used to create a phylogeny are called characters. Characters can be ancestral or derived. Ancestral characters exist in a species because they were also present in the ancestral species. * (Vague): Shared Derived characters are not found in the ancestral species because they evolved after the evolution of the newer lineage. * (Narrows it down): New Ex: Frogs, and turtles and leopards have four limbs because they share a common ancestor that had four limbs. Therefore, four limbs is a shared ancestral character of frogs, turtles, and leopards. Leopards have hair, but none of the other animals do because hair evolved after the mammal lineage diverged from the common ancestor shared by mammals and the other animals. Hair is a shared derived character found in all mammals. Shared ancestral traits and derived traits are placed in a character table to determine which animals share a common ancestor more recently and which share a common ancestor more distantly. From the character table, a phylogenetic tree can be constructed.

Know what transpiration is. Know transpiration's role in bulk water flow.

Transpiration: loss of water vapor through the stomata of a plant. Transpiration drives bulk-water flow. The bulk of water absorbed and transported through plants is moved by negative pressure generated by the evaporation of water from the leaves (i.e., transpiration) — this process is commonly referred to as the Cohesion-Tension (C-T) mechanism. Water gets uptaken by the soil from root hairs, cohesion and adhesion occurs in the xylem by hydrogen bonding and water then travels up the plant, and then transpiration occurs where water molecules leave from the stoma in the leaves out into the atmosphere through evaporation. The most negative water pressure is in the air, which is why water gets sucked up from the roots to the leaves. Cohesion and adhesion draw water up the xylem where water is required. Transpiration draws water from the leaf through the stoma. Water potential becomes increasingly negative from the root cells to the stem to the highest leaves, and finally to the atmosphere. Water potential is highest in the soil and decreases along the transpiration path. This potential gradient provides the driving force for water transpiration from the soil to the atmosphere.

Ecdysozoans: Arthropoda * How common are they relative to other clades? * What is their general body plan? * Circulatory type? * Function of spiracles? * Three major Arthropoda clades and examples of each? - Given an Arthropod by common name, (i.e. house fly), know which of the three major clades it belongs in.

Two out of every three known species of animals are arthropods. The arthropod body plan consists of a segmented body, hard exoskeleton, and jointed appendages. The body of an arthropod is completely covered by the cuticle. * an exoskeleton made of layers of protein and the polysaccharide chitin. * When an arthropod grows, it molts its exoskeleton (ecdysis). Evolution of the exoskeleton in early arthropods enabled them to be among the first animals to colonize land. * Its relative impermeability to water helped prevent dessication. * Its strength provided support without reliance on the buoyancy of water. Arthropods have eyes, olfactory receptors, and antennae that function in touch and smell. Arthropods have an open circulatory system in which hemolymph (a fluid analogous to blood). Hemolymph carries nutrients, salts, hormones, and metabolic wastes and is a vital part of the immune system. A variety of organs specialized for gas exchange have evolved in arthropods. * i.e. insects have spiracles - openings in the exoskeleton through which gas exchange can occur. Three major Arthropod lineages: * Clade Chelicerata (chelicerates) - Includes sea spiders, horseshoe crabs, scorpions, ticks, mites, and spiders. * Clade Myriapoda (myriapods) - Includes centipedes and millipedes. * Clade Pancrustacea (pancrustaceans) - Lobsters and other crustaceans - Insects and their relatives

Water Potential * Effect of water movement. * Component that make up water potential. - Solute/osmotic potential - what is it and what causes it to increase or decrease? - Pressure potential - what is it and what causes it to increase or decrease? - Matric potential - what is it?

Water potential is a measure of the free energy of water molecules and is the tendency for water to move. 1. Pressure Potential 2. Osmotic Potential 3. Matrix Potential When water moves into a cell, it becomes turgid. When water moves out, it becomes flaccid. When water moves into a cell, cell walls are strong enough to resist breakage by water absorption. When water moves out of a cell, incipient plasmolysis (wilted but perks back up) and plasmolysis (can't perk back up) can occur. Water moves from higher (less negative) to lower water potential (more negative) until equilibrium is reached. POSITIVE PUSHES, NEGATIVE PULLS (LESS - TO MORE -). When the water potential in the cell is higher than outside of the cell, water is being pushed out of the cell. Plasmolysis is defined as the process of contraction or shrinkage of the protoplasm of a plant cell and is caused due to the loss of water in the cell. When water moves out of a cell. EX. FLACCID CELLS. Cells become turgid when the water potential inside the cell is lower than the water potential outside of the cell, water is being pulled into the cell. Solute/Osmotic Potential: It is the potential of water molecules to move from a hypotonic (low solute conc.) solution to a hypertonic (high solute conc.) solution across a semi-permeable membrane. Solute potential decreases with increasing solute concentration and vice versa. Pressure Potential: increases as water enters a cell, and decreases as water exits a cell. Matrix Potential: the amount of water bound to the matrix of a plant via H-bonding.

Vascular tissue - Two types * Function of each type. * Structure of each type. * Type of cells. * Arrangement of cells.

Xylem cells: water-conducting vascular tissue. Lumen allows bulk water flow through plant. * Bulk water flow = long-distant transport of large amounts of water from soil to roots to stems to leaves and out to the air again. Transpiration drives bulk water flow. Tracheids: - In all vascular plants, i.e. ferns.Gymnosperms, and Angiosperm. - Tapered, overlapping. - Bordered pits allow water transport between tracheids. Pit-pairs are adjoining bordered pits. Pit membrane is an area with no secondary wall. Vessel Elements - Only in Angiosperm - Stacked into vessels - Perforations (no pit membrane) - Pit pairs Phloem cells: a type of vascular tissue. Sugar transport from source (leaves, stems) to sink (roots or petals). * Two types of phloem cells: -Sieve tube members: Angiosperm, stacks form sieve tubes. - Sieve cells: Gymnosperm and ferns. * Traits of phloem cells: - Elongated - Nuclei and other organelles disintegrate after maturity. - Need helper cells (minimal organelles, but no loss of organelle function due to helper cells). * Sieve tube members (Angiosperms) have companion cells. * Sieve cells (Gymnosperms and ferns) have albuminous cells. - Sieve cells and sieve tube members both have sieve pores (enlarged plasmodesmata) and sieve areas (aggregates of sieve pores). - Sieve tube members also have sieve plates.

Know the common name examples of each plant division.

brophytes: Hepatophyta, Bryophyta, Anthocerotophyta 1. Hepatophyta: Liverworts 2. Bryophyta: Mosses 3. Anthocerotophyta: Hornworts. Lycophyta and Monilophyta 1. Lycophyta: Lycophytes 2. Monilophyta: Monilophytes Gymnosperm: 1. Ginkgophyta: Ginkgo 2. Cycadophyta: Cycads 3. Gnetophyta: Gnetophytes 4. Pinophyta: Conifers Anthophyta 1. Anthophyta: Angiosperm/Flowering plants