AP BIO MASTER GUIDE

What is natural selection?

the process where individuals with traits that give them a higher chance of survival are more likely to reproduce, leading to the accumulation of favorable traits over time.

What creates variation among individuals in a species?

primarily created by mutations in genes and the different combinations of genes due to sexual reproduction.

What does the term 'fitness' refer to in a biological context?

refers to the ability of an organism to survive and produce fertile offspring.

What is the impact of selective pressure on a species?

a factor that influences survivability, determining which species have a better or worse chance of surviving.

How can environmental changes affect species over time?

can lead to adaptations in species, or in some cases, extinction if they cannot adjust to the new conditions.

What happens when populations become so different that they can no longer reproduce?

can lead to the formation of new species.

What is an example of a selective pressure mentioned in the lecture?

predators, such as birds or snakes, that influence the survival of species like mice.

What adaptation was noted regarding the peppered moths in response to pollution?

In response to pollution, light-colored moths had a disadvantage as pollution killed the lichen on trees, leading to an increase in dark-colored moths.

What is an adaptation in biological terms?

a characteristic or trait that gives an organism an advantage in surviving and reproducing in its environment.

What is the significance of mutations in evolution?

because they create genetic variation which is essential for natural selection and evolution.

How does mutation contribute to evolution?

creates genetic variation within a population, leading to new combinations of traits that can affect survival and reproduction.

What is the difference between phenotype and genotype?

Phenotype refers to the observable physical traits of an organism, while genotype refers to the genetic makeup that determines those traits.

What are the three types of natural selection?

The three types of natural selection are directional selection, disruptive selection, and stabilizing selection.

What is genetic drift?

Genetic drift is a change in the genetic composition of a population due to random events, often leading to significant differences over time.

What is gene flow?

Gene flow is the process by which new genes are added to a population through the arrival of new individuals, increasing genetic variation within the population.

What role does sexual reproduction play in genetic variation?

Sexual reproduction promotes genetic variation through processes such as crossing over during meiosis and the random fertilization of gametes.

What is the significance of a gene pool?

encompassesall the genetic information in a population, reflecting the genetic diversity and variation available for evolution.

What is evolution?

is the process through which species change over time through genetic variation and natural selection.

What is adaptation?

is a trait that increases an organism's chances of survival and reproduction in its environment.

What is a mutation?

is a change in the DNA sequence that can lead to new traits in a population.

What is artificial selection?

is the process by which humans breed plants and animals for specific genetic traits.

What is the role of the environment in evolution?

The environment influences which traits are favorable, affecting survival and reproduction.

What is temporal isolation?

occurs when two species breed at different times, preventing gene flow between them.

What is coevolution?

the process where two or more species evolve in response to each other.

What is convergent evolution?

occurs when unrelated species independently evolve similar traits due to adapting to similar environments.

What is divergent evolution?

when two or more related species become more dissimilar over time.

What is endemism?

refers to species that are found in only one specific geographic area.

What are analogous structures?

body parts in different species that have similar functions but evolved independently.

what is habitat isolation

occurs when two species live in different habitats within the same geographic area, preventing them from mating.

What is behavioral isolation

occurs when two species have different mating behaviors or rituals, preventing them from mating even if they live in the same area.

What is mechanical isolation?

occurs when two species are unable to mate due to physical differences in their reproductive structures.

what is gamete isolation

occurs when the sperm and egg from different species meet but fail to fertilize, preventing the formation of a zygote.

What is a postzygotic barrier?

is a reproductive barrier that occurs after fertilization, preventing the development of a viable or fertile offspring.

What is a characteristic that is typically found in eukaryotes?

a nucleus.

What are membrane-bound organelles?

Organelles that are enclosed by membranes, such as mitochondria and chloroplasts.

Give an example of a membrane-bound organelle important for energy production.

Mitochondria.

What is the purpose of the double membrane in mitochondria and chloroplasts?

It allows for the creation of a proton gradient essential for ATP synthesis.

What are linear chromosomes?

Chromosomes that are long and made of DNA, found in eukaryotes.

What is the difference between eukaryotic and prokaryotic genomes?

Eukaryotic genomes are large and linear, whereas prokaryotic genomes are circular.

What process involves the transformation of DNA to RNA?

Transcription.

What are exons?

Segments of RNA that are expressed and ultimately involved in protein synthesis.

What are introns?

Segments of RNA that are not expressed and are removed during RNA processing.

What is the role of ribosomes in mitochondria and chloroplasts?

They facilitate protein synthesis within these organelles.

What is the endosymbiotic theory?

The theory that mitochondria and chloroplasts originated from prokaryotes that were engulfed by a primitive eukaryotic cell.

What modifications are made to mRNA during processing?

Adding a GTP cap and a poly-A tail, and splicing out introns.

When DNA makes RNA, where does it go?

Ribosomes

What are Nucleic acids

“instructions “ for the sequence of amino acids that make up polypeptides

DNA produced RNA which produces __

Proteins

what contains the “code” for monomers

nitrodguenous base

structure of DNA are a __

Double helix

what are pyrimidines

single six-membered ringed nitrogenous bases

What are purines

six-membered rings fused to five-membered rings, nitrogenous base

what is chargaff's rule

a species will always have an equal amount of bases (A+T G+C equal)

what holds DNA together?

Hydrogen Bonds, the more the better

Dna strands are ___

Antiparallel

when making new copies of DNA, nucleotides are added at the ___

3’ (prime) end

What makes up a nucleotide

nitrogenous base, pentose sugar, phosphate

What is the Sugar in DNA

deoxyribose

What is the sugar in RNA

Ribose

What base does RNA have that DNA doesn’t?

U

What is Helicase?

untwista DNA strans into replication forks

What is Topoisomerase?

keeps the DNA from bunching up

What Are DNA polymerase?

synthesis DNA

What is Ligase

Joins okizaki fragments on lagging strand