STAAR Year Review Part 2

Theory of Evolution- the change in a population over time. (not a change in individuals!)

Mechanisms of Evolution- How does evolution happen?

Natural selection: a gradual process where traits become more or less common in a population. “Survival of the fittest” fittest- does not mean fastest or strongest. It means the one who had the most offspring.(know the three types, stabilizing selection, directional selections, disruptive selection)

Mutation: change in a gene; alteration of a nucleotide sequence

Migration: Movement of some individuals to another population

Genetic Drift: some individuals may by chance and not because of “fitness” leave more descendants and therefore pass on their genes.

Evidence for Evolution- The different type of support for the theory of evolution.

1. Fossil Record- buried animal and plant remains become fossilized in different layers of sedimentary rock.

2. Biogeography-Fossils and certain species are found in similar areas along lines where continents divided. Which is evidence for Pangea.

Oldest fossils

Newest fossils

STAAR Year Review Part 2

3. Homologies- root word “homo” means same. Having the following things in common is evidence of a common ancestor.

a. Anatomical: similar body structure i. Homologous structures : structures from one creature are similar to that of

another, evidence for common ancestry. Ex: Human arm and bat wing

ii. Analogous structure : Look similar but do not provide evidence for common ancestry. These traits have been developed because of adaptation to similar environments.

iii. Vestigial Structure: organs in the body that have no purpose but were used by a previous ancestor. Ex: hip bone on a snake.

b. Molecular- Comparing segments of DNA . The more nitrogenous bases the two species have in common, the more closely related they are. The more nitrogenous bases are different, the more distantly related the organisms are.

c. Developmental: (Embryology) The study of vertebrate organisms at the embryonic stage of life. They follow the same steps of development.

Taxonomy- the classification of all living organisms on the basis of what they have in common.

Domain DumbKingdom KingPhyllum PhillipClass CameOrder OverFamily ForGenus Good

Most broad/ general

STAAR Year Review Part 2

Species Soup

Ex: If you are in the same genus as another organism you are in all the other classifications above genus. (domain, kingdom, phylum, class, order, family)However, you would not necessarily be in the same classifications below genus. (species)

The Six Kingdoms

Most specific

STAAR Year Review Part 2

STAAR Year Review Part 2

Kingdom Plantae:

Autotroph- an organism that creates organic compounds (glucose, food) from inorganic compounds (Carbon dioxide, water, sunlight).

Reproductive system of a plant:

o

STAAR Year Review Part 2

Transport system of a plant:o Xylem: Moves water up. From the roots to the rest of the plant.

o Phloem: Moves sugar that is produced in the leaves down throughout the rest of the plant

Response system of a plant:o Geotropism: Downward growth of the roots showing positive geotropism. The

upward growth of the stem showing negative geotropism.

o Phototropism: The movement of a plant towards a light source. o Thigmotropism: The response of a plant to touch. Ex: venus flytrap

Photosynthesis- In plants only. Converts radiant energy (sun) into chemical energy (food) Occurs in the chloroplast or in the chlorophyll of cells with no membrane bound organelles.

Cellular Repiration- A process done by both animals and plants. Where chemical energy (food) is converted into usable energy for the organism (ATP). Occurs in the mitochondria.

Ecological Succession-