-An RNA virus that reproduces by means of a DNA molecule.

-Copies its RNA to DNA using reverse transcription.

Retrovirus

-Acquired immune deficiency syndrome

- The disease caused by HIV infection

- One of the most significant health challenges facing the world today

What is AID's treated with?

1) HIV

2) Ebola

3) West Nile

How do new viruses arise?

(3 ways)

1) Mutation of existing viruses

2) Spread to new host species

3) Spread from isolated populations

-Severe acute respiratory Syndrome

-8,450 people infected

-10% died

Yes.

Ex: Identical twins

-All contain a complete genome

-Have the potential to express all of an organism's genes

False

It can produce hundreds of thousands of clones.

Produces embryonic stem cells 

Cloning a specific cell for something good

Ex: Diabetes

What was the first mammal cloned in 1997?

And what kind of cloning was it?

Dolly, the sheep

Reproductive Cloning

Adult Stem Cells

-Generate replacements for nondividing differentiated cells.

-Are unlike embryonic stem cells, because they are partway along the road to differentiation

-Master control genes

-Regulate many other genes

-Help direct embryonic development in many organisms

-Are sequences of nucleotides common in many organisms

-Can turn groups of genes on and off during development

-Organisms can change over generations

-Individuals with certain heritable traits leave more offspring than others

-Organisms inhabiting Earth today descended from ancestral species

-Natural selection was the mechanism for descent with modification

-Preserved remnants or impressions left by organisms that lived in the past

-Are often found in sedimentary rocks

-Have to die in the right place

Evidence of Whale evolution

(3)

1) Pelvis and legs in ancestral whales

2) The progression of nostrils at front of the head and moving backward

3) Correlation between swimming movements of marine mammals and terrestrial mammals (movements different from fish)

-The study of the geographic distribution of species

-First suggested to Darwin that today's organisms evolved from ancestral forms.

-Changes in an organisms DNA

-Alone do not have much effect on a large population

-Can have significant cummulative effects on a population

-The comparison of body structure between different species

-Confirms that evolution is a remodeling process

The comparison of structures that appear during the development of difference organisms

-Coparative embryology of vertebrates supports evolutionary theory

1) Overproduction

-All species tend to produce excessive numbers

-Leads to a struggle for existence

2) Individual Variation

-Variation exists among individuals in a population

-Much of this variation is heritable

3 examples of natural selections:

1) Pesticide resistance in insects

2) The development of antibiotic-resistant bacteria

3) Drug-resistant strains of HIV

-Is a group of individuals of the same species living in the same place at the same time

-Is the smallest biological unit that can evolve

-Focuses on populations as the evolutionary units

-Tracks the genetic makeup of populations over time

-A mathematical representation of a gene pool

-Adds up all of the genotypes in a population

1) Genetic drift

2) Gene flow

3) Mutations

4) Natural selection

-Is an example of genetic drift

-Results from a drastic reduction in a population size

-Bottlenecking in a population usually reduces genetic variation

-Affects about one out of every 400 African Americans

-Is more common among African Americans

-Confers resistance to the disease malaria

-Is adaptive in the African tropics where malaria is common

T/F: Since all moquitoes look roughly alike, they all only bite humans.

False.

They all do look roughly alike but there are many distinct species, 2 of which may bite birds or people.

Macroevolution

-Encompasses the major biological changes evident in the fossil record

-Includes the formation of new species

-Is the focal point of macroevolution

-May occur based on two contrasting patterns

No.

For example, not with fossils and asexual organisms.

Prezygotic Barriers include:

(4)

-Temporal Isolation

-Habitat Isolation: Doesn't live in the same place

-Mechanical Isolation: Can't physically interact

-Gametic Isolation: Eggs and sperm don't get to one another

1) Allopatric Speciation

2) Sympatric Speciation

-Can fragment a population into two or more isolated populations

-Can contribute to allopatric speciation

A mechanism of sympatric speciation

-First observed by Hugo de Vries

-Works best in plants

-Can originate from accidents during cell division

-Can result from the hybridization of 2 parent species

-Involves a structure that evolves in one context gradually becoming adapted for other functions

-Is a mechanism for novel features to arise gradually through a series of intermediate stages

-Used for one particular thing

-Is the retention of juvenile body features in the adult

-Is important in human evolution

1) Species richness: the total number of different species in the community

2) Relative abundance of the different species.

- May occur when 2 or more species in a community rely on similar limiting resources

- May limit population growth of the competing species

-Is the sum total of a species' use of the biotic and abiotic resources in its environment

-Is the species' ecological role

Two species cannot coexistin a community if their iches are identical

1) Extinction of one species

2) Evolution of one species to use a different set of resources

Is the differentiation of niches that enables similar species to coexist in a community

What is one way 2 very similar species can avoid the consuquences of the competitive conclusion principle?

-Organisms eat other organisms

-Identifies the predator as the consumer and the food species as they prey

-Includes herbivory, the consumption of plants by animals

1) Chemical toxins

2) Spines and thorns

-Removed a dominant predator from a community

-Provided evidence of the importance of predation

-Refers to the community's ability to resist change and return to its original species combination after being disturbed.

-Depends on both the type of community and the nature of disturbances.

-Are episodes that damage biological communities, at least temporarily

-Destroy organisms and alter the availability of resources

-Affect all communities.

-Often have positive effects on a community

-May create new habitats

What is an ecosystem's primary productivity?

The rate at which plants and other producers build biomass