Col Bio Unit 4 Review

Geological formations and species variation, which helped him learn that species adapt and change according to their environment, also called evolution.

List two observations Darwin made on his voyage that influenced the development of his theory.

Lamarck believed that giraffes necks stretched in order for them to reach leaves, but Darwin claimed that only the giraffes with long necks survived since they were the only ones who could reach the leaves.

Identify how Darwin’s and Lamarck’s theories of evolution are different.

1. Individual organisms in a species show variation that can be passed from one generation to the next.
2. Organisms compete for available resources.
3. Individual organisms in a population differ in terms of their reproductive success.
4. Organisms become adapted to conditions as the environment changes.

What are the four main observations that makeup Darwin’s theory of natural selection?

All the changes that have occurred, due to differential reproductive success, in living organisms over geological time.

Define biological evolution.

Fossils, biogeographical evidence, anatomical evidence, biochemical evidence.

What are the four lines of evidence for evolution.

The remains and traces of past life or any other direct evidence of past life. Serve as transitional links between groups.

\*EX: shells, bones, teeth, footprints, burrows, casts.

What are fossils (*four lines of evidence for evolution*)?

This uses biogeography, which is the study of the range and distribution of plants and animals in different places throughout the world.

\*EX: continental drift.

What is biogeographical evidence (*four lines of evidence for evolution*)?

What is anatomical evidence (*four lines of evidence for evolution*)?

This uses homologous structures and vestigial structures.

What is biochemical evidence (*four lines of evidence for evolution*)?

This is when almost all organisms use the same basic biochemical molecules, including DNA, ATP, and enzymes.

\*EX: humans share many genes with much simpler organisms, organisms have similar DNA sequences.

What is a homologous structure?

Anatomically similar structures because they are inherited from a common ancestor.

\*EX: human arm and whale forelimb.

What is a vestigial structure?

Anatomical structures fully functional in one group and reduced or nonfunctional in another.

\*EX: snakes have no use for hindlimbs, some have remnants of hindlimbs.

List the 5 conditions necessary for the allele frequencies of a population to be in Hardy-Weinberg equilibrium.

1. No mutations.
2. No genetic drift.
3. No gene flow.
4. Random mating.
5. No selection.

Identify how a population can evolve from a change in its frequencies over generations.

**1ST POPULATION: brown beetle 75%, green beetle 25% 2ND POPULATION: brown beetle 70%, green beetle 30%. Population is evolving into higher green allele frequency over time.*

Basically, if you have a phenotype favored, then over time that will become a higher percent until another phenotype becomes favored.

What are the 5 agents of evolutionary change?

1. Mutations.
2. Genetic drift.
3. Gene flow.
4. Nonrandom mating.
5. Natural selection.

What are mutations?

The genetic changes that are the only source of new variation in a population, can have advantages and disadvantages.

\*EX: a type of mutation that gives bacteria resistance to antibiotics appears by chance).

What is genetic drift?

A change in allele frequencies of a gene pool due to random meeting of gametes in fertilization.

\*EX: the death of one individual in a population of 10 could change the frequency of an allele by 10% or cause its loss altogether.

What is gene flow?

The movement of alleles between populations.

\*EX: adult plants are not able to migrate, but their pollen is often blown by the wind or carried by insects into different populations.

What is nonrandom mating?

This occurs when individuals are selective about choosing a mate with a preferred trait.

\*EX: mating of close relatives.

What is natural selection?

A process that allows some individuals with an advantage over others to produce more offspring.

\*EX: ligers cannot reproduce.

List the 4 requirements of evolution by natural selection.

1. Individual variation.
2. Inheritance.
3. Overproduction.
4. Differential reproductive success.

What is the bottleneck effect?

This occurs following a natural disaster that kills a large proportion of a population.

What is the founder effect?

This occurs when a few individuals form a new colony and their collective genes represent only a fraction of the original gene pool.

What is stabilizing selection?

This is when individuals near an average phenotype are favored (extreme phenotypes are selected against).

\*EX: human infants born with an intermediate birth weight have a better chance of survival that those of either extreme.

What is directional selection?

This can occur when the population is adjusting to a changing environment (one extreme phenotype is favored).

\*EX: when bacteria are exposed to an antibiotic, most are susceptible an die, but some are resistant and survive to reproduce.

What is disruptive/diversifying selection?

When two different habitats could result in two different phenotypes in the population (two or more extreme phenotypes are favored).

\*EX: british land snails with dark shells are more prevelant in forested areas.

What are the 3 types of natural selection?

1. Stabilizing selection.
2. Directional selection.
3. Disruptive selection (or diversifying).

Distiguish between prezygotic and postzygotic isolation mechanisms.

**Prezygotic** isolation mechanisms are in place before fertilization and make no attempt at reproduction, while **postzygotic** isolation mechanisms are in place after fertilization and reproduction may take place.

Explain how adaptive radiation can lead to speciation.

A species adapts to a new environment and are able to live longer (**adaptive radiation**), which can lead to **speciation** because they are prolonging their life, and it is more possible to create more species.

Compare and contrast gradualism with punctuated equilibrium.

**Gradualism** is a slow but steady change before and after divergence, and **punctuated equilibrium** is long periods of growth followed by rapid speciation.

Recognize how phylogenetics, the theory of evolution, and classification are interrelated.

**Phylogenetics** are the branch of systematic biology that studies the evolutionary relatedness among groups of organisms.

The **theory of evolution** states that if an environment changes, the traits that enhance survival in that environment will also gradually change, or evolve.

**Classification** is the process of naming and assigning organisms or groups of organisms to a taxon.

What is the goal of systematic biology, and its two branches of study?

The goal of systematic biology is to infer the evolutionary relationships among organisms and organize the biodiversity based on these relationships.

Its two branches of study are taxonomy and phylogenetics.

What is the goal of taxonomy?

Its goal is to identify, name, and classify organisms.

What is the goal of phylogenetics?

Its goal is to study evolutionary relationships between groups of organisms.

Interpret the information provided in both a cladogram and a phylogenetic tree.

A **cladogram** shows the relationship between different species based on the most recent common ancestor, and shared characteristics. A **phylogenetic tree** is essentially a family tree, and is based on a number of DNA base-pair differences.

Describe the contributions of Leeuwenhoek and Pasteur to the science of microbiology.

Leeuwenhoek improved the quality of microscopes in the late 1600s, Pasteur conducted experiments and disproved the theory of spontaneous generation in 1859.

Explain what is meant by the term microbiota.

Microbes.

Provide several specific examples of the beneficial effects of microbes.

Nutrient cycling, photosynthesis, and bioremediation.

Distinguish between chemical and biological evolution.

The first organic molecules came from chemically altered inorganic molecules (so, they went through **chemical evolution**). The complex organic macromolecules were synthesized to create polymers and were enclosed in a plasma membrane to create a protocell. The protocell then went through **biological evolution** to produce the first self-replicating and living cell.

List some of the major criteria used to distinguish the domains Archaea, Bacteria, and Eukarya (cell membrane, size, and environment).

**Archaea**: monolayer of lipids with branched side chains, 0.1 to 15 micrometers in size, found in moderate environments such as lake sediments and soil.

**Bacteria**: lipid bilayer and cell wall, 0.2 to 10 micrometers in size, found in basically every kind of environment.

**Eukarya**: phospholipid bilayer, 10-100 micrometers in size, found in natural environments such as soil and freshwater.

Identify the structural features of archaea.

They have a monolayer of lipids with branched side chains. Their cell walls are usually composed of polysaccharide or pure protein. Some even have no cell wall.

Explain how the plasma membranes of archaea differ from those of bacteria and eukarya.

Bacteria and eukarya have a lipid bilayer, while archaea have a monolayer of lipids with branched side chains.

What are the three typical shapes of bacteria?

Rod, sperical, and spiral or helical.

Describe bacterial reproduction, including three mechanisms by which bacteria increase genetic diversity.

Bacteria reproduces asexually. Three mechanisms include **endospores** (survive in harsh conditions), **conjugation** (when a donor cell passes DNA to a recipient cell through sex pilus), and through **transduction** (viruses carry portions of bacterial DNA from one bacterium to another).

Identify the difference between gram positive and gram negative bacteria.

Gram + bacteria stains purple, and gram - bacteria stains pink.

Acellular (not composed of cells), are obligate parasites (only reproduce in a living cell). They are not considered living because they are acellular and have been synthesized in a lab from chemicals.

Describe the characteristics of viruses, and explain why they are not considered living.

Structurally diverse, mostly single-celled, high level of complexity.

Describe the general characteristics of protists.

They reproduce sexually and asexually (mostly asexual).

Explain how protists reproduce.

Protists can gain food from photosynthesis (algae) or from the environment (protozoans).

Explain how protists obtain food.

They are considered so diverse because they did not evolve from a single common ancestor, which has been shown through DNA evidence.

Why are protists considered so diverse?

1. Plant-like (ex: green algae).
2. Fungi-like (ex: water mold).
3. Animal-like (ex: ciliates).

What are the 3 types of protists? Give an example of each.

Release digestive enzymes into their external environment and digest food outside the body, breaking down complex organic molecules.

Describe the general characteristics of Kingdom Fungi.

Spores are important because they help the fungi to reproduce, also are how fungi are classified.

Why are spores important?

Fungi obtain nutrients by absorbing the nutrients in their surrounding environment via hyphae.

Explain how fungi obtain their nutrients.

Fusiform shape.

What shape does the hyphae have?

Long filamentous branches in fungi. This is how they absorb their nutrients.

What is a hyphae?

It produces spores, which are then dispersed for reproduction.

What does the fruiting structure (body) of fungi produce?

Dead and living trees, and dead animals.

What are two typical fungal food sources?

They are both heterotrophs (rely on other sources for food).

How are fungi like animals?

Contain chlorophyll, store excess carbohydrates and have cellulose in their cell walls.

Identify features present in the ancestors of land plants that helped give rise to today’s land plants.

1. *Mosses* were the first to have a form of **protection for the embryo**, which kept it from drying out.
2. *Lycophytes* were the first to evolve **vascular tissues**, which transport water and nutrients throughout the plant’s body.
3. *Ferns* evolved **megaphylls**, which are large leaves that increase surface area for photosynthesis.
4. *Gymnosperms* were the first with **seeds**, which contain the embryo and supportive nutrients in a protective coat.
5. *Angiosperms* are the **only ones to have flowers**, which attract a variety of pollinators and give rise to fruits.

List the major events in the evolutionary history of plants.

A life cycle where two multicellular individuals alternate, each producing the other. The sporophyte represents the diploid generation, and the gametophyte represents the haploid generation.

Describe the alternation of generations in plants.

They have the alternation-of-generations life cycle, their bodies are covered by a waxy cuticle that controls water intake, and they are low lying to the ground.

Identify traits of nonvascular plants that enable them to survive on land.

It is helpful in the transport of water and organic nutrients throughout the body of the plant, allows them to grow vertically.

Explain the importance of vascular tissues to plants.

They have a seed coat that produces the embryo and food and helps them to survive in harsh conditions.

List the features of seed plants that make them fully adapted to life on land.

1. They have power of movement or locomotion due to muscle fibers.
2. They are multicellular.
3. They have a life cycle where the adult is usually a diploid.
4. Undergo sexual reproduction and their embryo goes through developmental stages.
5. They are heterotrophic.

List the general characteristics of animals.

Asymmetrical, radial symmetry, and bilateral symmetry.

What are the 3 types of symmetry found in animals?

When animals have no particular symmetry.

\*EX: sponges.

Explain asymmetrical symmetry.

Means the animal is organized circularly like a wheel.

Explain radial symmetry.

Means the animal has definite right and left halves.

Explain bilateral symmetry.

Invertebrates have no internal skeleton, vertebrates do.

List characteristics of invertebrates (think about what makes a spider and spider, and a sponge a sponge).

1. Notochord.
2. Nerve chord.
3. Pharyngeal pouches.
4. Postanal tail.

Identify characteristics unique to chordates.

Cartilage-like supportive dorsal rod in all chordates at some time in their cycle; replace by vertebrae in vertebrates.

What is a notochord (chordates)?

Component of an invertebrate’s nervous system; usually located ventrally in invertebrates in invertebrates; commonly called the spinal cord in vertebrates.

What is a nerve cord (chordates)?

Developmental characteristic of a chordate; these may develop into gills, or other structures such as auditory tubes and glands.

What is the pharyngeal pouches (chordates)?

Characteristics of a chordate; tail extends past the anus of the digestive system.

What is a postanal tail (chordates)?

Lancelets and tunicates.

What are the two nonvertebrate chordate groups?

Found in shallow water along coasts, feed on microscopic particles.

Describe the features of lancelets.

Live on the ocean floor, squirt water from siphons when disturbed.

Describe the features of tunicates

Some fish may have been able to move from pond to pond because they were lobe-finned.

Dealing with the means of reproduction that is suitable for land existence - EGGS!

Describe the major evolutionary innovations that distinguish the fish from amphibians.

Monotremes, marsupials, and placentals.

What are the 3 groups of mammals?

They have a cloaca (a terminal region of the digestive tract that acts as a common chamber for feces, excretory wastes, and sex cells).

Describe the characteristics of monotremes.

They are born in the female’s body but are born in an immature condition.

Describe the characteristics of marsupials.

The baby is developed inside the mother.

Describe the characteristics of placentals.

Reptiles give birth by laying eggs, mammals give birth to live young. Reptiles are also ectothermic, so they match the temperature of their environment, while mammals are warm-blooded.

Identify the evolutionary changes that distinguish mammals from reptiles.

Birds lay hard-shelled eggs and reptiles lay leathery eggs.

List the features that distinguish the characteristics that separate birds and reptiles.

1. Monotremes lay hard-shelled amniotic eggs.
2. Marsupials are born in an immature condition.
3. Placentals are developed inside the mother.

Identify the unique features to the 3 living lineages of mammals.