AP Bio Overall

Endotherms

Warm blooded creatures, animals that regulate their body temperature

Ectotherms

Cold blooded creatures, animals that can’t regulate their body temperature.

Energy availability vs population growth

Higher availability leads to more focus on reproduction, leading to higher population growth. The opposite is true.

Biotic Factors

Living organisms in a population that affect other organisms

Abiotic Factors

Nonliving factors within a population that can affect organisms

Population

A group of the same species in a area

Community

All the different populations in a area

Ecosystem

THe community of organisms along with other abiotic factors

Biome

Geographic area with similar climate and vegetation throughout

Source of all energy

Sun

10% rule

Only 10% of the energy is preserved when moving from one trophic level to the next

Nutrient Cycling

Elements are always cycled and are never actually spent or disappear.

Autotroph

Organisms that create their own energy

Heterotroph

Organisms that consume other organisms for energy

Carnivores

Organisms that only consume other animals

Herbivores

Organisms that only consume plants

Omnivores

Organisms that consume both plants and animals

Decomposers

Organisms that break down dead matter and release nutrients back to the environment

Scavengers

Organisms that consume dead matter as food.

Population growth model with unlimited resources

Exponential Growth

Carrying Capacity

The maximum population size that can be supported by the environment.

Species diversity

The variety and number of species within an ecosystem

Simpson’s Diversity index

A measure of the diversity within a community. Higher number correlates to more diversity.

Competition

Interspecies interaction where both organisms fight for the same limited resources and both are worse off because of it.

Mutualism

Interspecies interaction where both species benefit

Commensalism

Interspecies interaction where one organism is helped and the other is not affected.

Predation

Interspecies interaction where one species consumes the other and is thus benefited while the other is harmed.

Trophic Cascade

The negative effect on other trophic levels resulting from the removal of a species.

Parasitism

Interspecies interaction where one species benefits from leeching off the other

Niche Partitioning

Decrease in competition over limited resource sdue to species accessing the resource in different ways.

Keystone Species

Species which have a disproportionately large role in their ecosystem and balance several other species.

Invasive Species

Non-native species that harm the communities they are introduced to as they lack predators and can out compete other species.

Mutations

Random changes in DNA sequences that alter a organism’s genome

Genetic Drift

Change in the frequency of alleles within a population by random chance alone. More of a problem in small populations.

ex: an organism with a uncommon trait has more offspring than any other organism of that generation by chance alone.

How phenotypic changes occur

Random mutations compound to change phenotypic frequencies.

Fitness

How well an organism is able to survive and reproduce

Bottleneck

Death of the majority of a population that leads to the remaining population having drastically reduced phenotypic variation.

Founder Effect

Migration of a small group of organisms within a species, with the resulting population that that group produces having greatly reduced genetic variation.

Migration/Gene Flow

Movement of individuals between different populations, leading to decreased genetic variation between different populations.

No mutations, Random mating, no Gene Flow, no Genetic Drift, no Natural Selection

Conditions for Hardy Weinberg Equilibrium

Hardy Weinberg Equilibrium

Equilibrium where the frequencies of two alleles remains constant across generations.

p + q = 1, p² + 2pq + q² = 1

Biological Species definition

Species are a group of organisms which can interbreed and create viable, fertile offspring.

Speciation

The creation of new species.

Divergent evolution

Evolution of different phenotypes/traits among different groups, often due to differing environmental pressures.

Adaptive Radiation

Evolution of new species into empty ecological niches

Convergent evolution

Evolution of similar traits across different unrelated species due to similar environmental pressures

Analogous Structures

Similar traits in unrelated species

Punctuated Equilibrium Model

The idea that nothing happens for very long periods and evolution only occurs during punctuated bursts of drastic environmental change.

Stasis

Periods where there is little to no change

Gradualism model

The idea that evolution occurs gradually over long periods of time, consistent with gradual environmental change.

Pre-zygotic Barriers

Barriers that occur before zygotes are even formed.

Habit Isolation

Separation of species through differing habitats.

Note: Pre-zygotic barrier.

Temporal Isolation

Separation of species due to differences in breeding times

Note: Pre-zygotic barrier

Behavioral Isolation

Separation of species due to differing behaviors.
Note: Pre-zygotic barrier.

Mechanical Isolation

Separation of species due to preventative differences in reproductive structures/structures as a whole.

Note: Pre-zygotic barrier.

Gamete Isolation

Separation of species due to one species’ sperm not being able to fertilize the egg of another.

Note: Pre-zygotic barrier.

Post-Zygotic Barriers

Barriers that occur after zygotes form

Hybrid Inviability

Separation of species because hybrid mating produces underdeveloped/stillborn offspring.

Note: Post-zygotic barrier.

Hybrid Sterility

Separation of species because hybrid mating produces sterile offspring.

Note: Post-zygotic barrier.

Hybrid Breakdown

Separation of species because hybrid mating produces viable offspring, but the following generation of hybrid offspring are not viable.

Note: Post-zygotic barrier.

Allopatric Speciation

Physical, geographical separation of two different species, which leads to the different groups developing into different species.

Sympattric Speciation

Reproductive isolation between different groups of organisms within a species that lead to the development of different species.

Directional Selection

Selection that favors one extreme over the other and shifts the population towards that extreme.

Stabilizing Selection

Selection that favors intermediates rather than extremes.

Disrupting Selection

Selection that favors both extremes, which could lead to speciation

RNA World Hypothesis

Hypothesis that RNA was the earliest genetic material and was the first “living“ lifeform.

Organic Molecules and Monomers

Complex building blocks of life that can occur without living organisms to make it.

DNA

Double stranded string of nucleotides that codes for proteins and thus genetic material

RNA

Single stranded string of nucleotides that can be used to store genetic information or perform other functions

Prokaryotic genomes vs Eukaryotic Genomes

Prokaryotic genomes are smaller, and have circular chromosomes in the cytoplasm. Eukaryotic ones are larger and pack genetic material into linear chromosomes.

Plasmids

Short loops of DNA found within prokaryotes that can be incorporated into other molecules.

DNA parts

Phosphate group, deoxyribose pentose sugar, nitrogenus base.

RNA parts

Phosphate group, ribose pentose sugar, nitrogenus base.

Base Pairing Rule

G to C, A to T/U.

Pyrimidines

Single ringed bases. U, C, and T

Purines

Double ringed bases, A and G

DNA Replication

Semi-conservative process in which DNA is duplicated.

Semi-conservative

Process in which DNA is created but some of the original is conserved.

5’ end

Side with the phosphate group

3’ end

Side with the hydroxyl group(without the phosphate group)

Antiparallel

Each side faces the opposite direction, the 5’ end faces the same direction as the 3’ end of the other.

Leading Strand

Strand which is produced in one continuous link, from 5’ to 3’

Lagging strand

Strand which is produced in fragments from 3’ to 5’

Enzymes involved in DNA synthesis

Helicase, Topoisomerase, DNA polymerase, Ligase, Primase

Helicase

Splits DNA open at the replication fork into two single strands.

Topoisomerase

Prevents the DNA from tangling on itself again after being seperated by helicase

Replication fork

Point at which the DNA is splitting into two.

DNA polymerase

Creates new DNA strands with free floating nucleotides.

Restrictions of DNA Polymerase

Can only attach onto the 3’ end of a preexisting strand.

Ligase

Enzyme which joins okazaki fragments together

Okazaki Fragments

Short segments of appended nucleotides created when the DNA polymerase attaches from 3’ to 5’.

Introns

Noncoding parts of the mRNA strand

mRNA

Messenger RNA, the form genetic material is turned into during transcription

Transcription

Process in which mRNA is created from DNA.

Template DNA/non-coding strand/antisense strand

Strand that mRNA is appended onto to create the strand.

Non-template strand/coding strand

The strand of the DNA which mirrors the mRNA strand created. mRNA is not created on it.

Codons

Sequence of three nucleotides that codes for an amino acid.

RNA splicing

Process in which introns are spliced out of mRNA strands.

Exons

Coding parts of the mRNA strand.

Alternative Splicing

The introns for one protein might be the exons for other. When splicing mRNA down, the splicing is determined by the actual protein being created such that a single segment of mRNA can be spliced to create many different proteins