BIO Exam 1

Biology is …

The study of life

7 characteristics of life

1. Growth, development, reproduction

2. energy utilization

3. cell (s)

4. homeostasis

5. ordered complexity

6. evolutionary adaptions

7. sensitiviy

Levels of organization

atoms

molcules

macromolecules

organelles

cells

tissues

organs

organisms

populations

communities

ecosystems

biosphere

Inductive reasoning

uses related observations to arrive at a general conclusion (bottom up)

Deductive reasoning

uses a general principle or law to forecast specific results (top down)

The process that inductive reasoning involves

1. the use of general principles to predict specific results

2. the use of specific observations to develop general principles

3. the use of general principles to support a hypothesis

4. the generation of specific predictions based on a belief system

Scientific Method

1. pose a question and seek science based responses

2. inductive methods for scientific inquiry

3. research from almost all fields of study can apply it as logical, rational problem solving method

Scientific method steps

1. observe

2. question

3. hypothesis

4. prediction

5. experiment

6. results

Hypothesis

explanation for observation

must be tested to determine its validity

often tested in many different ways

allows for predictions to be made

repeatable

Experiment

test hypothesis

tests one vairable at a time

has three variables: independent, dependent, and control

Qualitative

descriptions, data observed

Quantitative

numbers, and measurments

Scientific Theory

supported by large body of scientific research, with minimal influence of human bias. NOT A SOCIAL THEORY

Evolution

change over time in a population of a species

Misconceptions of evolution

humans decending from monkeys

individual instead of population= wrong

Macroevolution

rise of new species (from old) and higher taxonomic groups with widely divergent characteristics

Microevolution

Change in a population, change in heritable characteristics/ allele/ gene frequency over time, can be observed over short periods of time

Mechanisms of evolution

1. mutation

2. natural selection

3. gene flow

4. genetic drift

5. recombination

6. non-random mating

7. “MaNaGGeRR”

Mutation

a rare change in DNA

is the ultimate source of new alleles or new genetic variation in any population

point mutation example

sickle cell anemia

natural selection

enviroment plays key role

genetic variation= raw material for selection

operates on the individual

Gene Flow

the flow of alleles in and out of a population due to the migration of individuals

can occur when a individual travels from one geographic location to another

Modes of evolution

mutations

natural selection

gene flow (migration)

genetic drift (random)

Types of evolution

microevolution

macroevolution

convergent evolution

divergent evolution

gradualism

punctuated equilibrium

cladogenesis

anagenesis

Genetic Drift

random

no advantage to population over existing allele frequencies

in small populations

Small populations result from …

population bottleneck

flounder effect

Bottleneck (random)

a change event or catastroph can reduce the genetic variability within a population

natural events such as an earthquake disatster that kills, at random, a large population.

Flounder effect

Think of it as individuals are “founding” a new population. allele frequency change in an isolated part of the population.

Recombination

offspring differ from parents

combination of genetic material from two different gametes

Non-random mating

The probability that two individuals in a population will mate is not the same for all possible pairs of individuals

3 conditions for natural selection (VIC)

Variation

Inheritance

Competition

VIC- Variation

individuals within a population have different characteristics or types

VIC- Inheritance

offspring inherit traits from their parents (transmission to next generation)

VIC- Competition

offspring with traits better matched to the enviroment survive and reproduce more effectively than others

Sickle Cell Anemia

reduced ability to deliver oxygen

the cell can’t pass through capillaries= painful clots

Alfred Russel Wallace

as species colonize they take on distributions they have today

Convergent evolution

similarities due to similar selection pressurses

similar phenotypes evolve in distantly related species due to same evolutionary pressures

Evidence of macroevolution

Analogus characters and Homologous characters

Analogus Characters

similar due to functional or ecological constraints/ pressure

Homologous Characters

similar due to evolutionary orgin (same ancestral source)

Types of selection

artifical

natural

stabilizing

directional

disruptive

sexual

intrasexual and intersexual

Stabilizing

individuals with average phenotypes are favored

Directional

individuals that vary in one direction from the mean are favored

disruptive

individuals at both extremes are favored

sexual

traits that inhance reproductive success

intrasexual

improves ability to compete for mates

intersexual

ability to attract oposite sex

Biological species concept

produce viable offspring

Ecological species control

The concept of a set of organisms exploiting or adpated to a single enviroment

Phylogenetic Species

The concept of a species as an irreducible group whose members are dead from a common ancestor and who all possess a combination of certain traits

Evolutionary species concept

the conept of a lineage evolving seperatly from others and with its own unitary evolutionary roles and tendencies

Speciation

formation of two species from one original species

How does speciation occur?

Anagenesis and Cladogenesis

Anagenesis

when a population of entire species changes on genetic level without split. (ancestral pop. goes extinct)

Cladogenesis

Species splits into two genetically distant pops. adapted to different ecosystems and/or survival strategies

Allopatric speciation

involves geographic isolation

sympatric speciation

occurs in the same geographical area

Adaptive Radiation

a group of species that has evolved into numerous, diverse forms

Reproductive isolation

Prezygotic and Postzygotic

Prezygotic

temporal isolation: different breeding schedules

habitat isolation: members move or otherwise seperate

behavioral isolation: actions or behaviors impact reproduction

mechanical isolation: reproductive systems dont fit together

gametic barrier: difference in their gamete cells, parent fertilization

Postzygotic

hybrid inviability: embryo is produced, but cant survive

hybrid sterility: different species can produce viable offspring but the offspring cannot reproduce

speciation

formation of two species from one original species

Temporal isolation

species have different breeding schedules

Habitat isolation

members of species move or otherwise seperate

behavioral isolation

certain actions or behaviors impact reproduction

mechanical isolation

their reproductive structures simply do not fit together

Gametic barrier

differences in their gamete cells prevent fertilization