Review Flashcards

Flashcards for exam review.

Natural Selection

Process where organisms with favorable traits are more likely to survive and reproduce.

Overproduction

Organisms produce more offspring than can survive.

Competition

Individuals compete for limited resources.

Variation

Differences in traits occur naturally and are heritable.

Adaptation

Accumulation of favored traits in a population over time.

Biological fitness

An individual's ability to survive and reproduce successfully.

Fossils

Evidence of past life, confirming existence of extinct species.

Molecular evidence

Similar DNA, amino acids, triplet codes, enzymes, ATP, etc.

Analogous structures

Same function, different structure.

Homologous structures

Same structure, different function.

Vestigial structures

Structures that are no longer in use.

Directional selection

One extreme phenotype is more fit.

Stabilizing selection

Intermediate phenotypes more fit than extreme ones.

Disruptive selection

Both extreme phenotypes more fit.

Sexual selection

Selection based on the ability to attract a mate.

Genetic drift

Allele frequencies change over time due to random chance.

Bottleneck effect

Population is reduced rapidly, typically affecting small populations.

Founder effect

Small portion of population migrates to a different area.

Gene flow

When an individual moves, they bring their genes with them.

Allopatric Speciation

Isolation is due to a physical geographical barrier separating individuals.

Sympatric Speciation

Individuals have the potential to be in the same place at the same time but don't interbreed.

Helicase

Unwinds/unzips the double strand of DNA.

Topoisomerase

Relieves strain ahead of the replication fork by breaking, swiveling, and rejoining DNA strands.

Single Strand Binding protein

Stabilizes unwound DNA strands, preventing rebonding.

Primase

Sets RNA primers on the DNA template.

DNA pol III

Adds nucleotides to the 3' end of a DNA strand.

DNA Pol I

Removes RNA primers and replaces them with DNA nucleotides.

Ligase

Ties sugar-phosphate backbone together.

Nuclease

Removes any mistake nucleotides.

RNA splicing

Spliceosomes remove introns and connect exons.

RNA polymerase

Binds to promoter and separates DNA strands during transcription.

Repressors

Bind to operators, reducing transcription.

Activators

Increase transcription of operon.

Inducible Operon

Usually off but can be turned on.

Repressible operon

Usually on but can be turned off.

LAC Operon

Builds lactose, inducible operon.

Enhancer

Increases probability of transcription (DNA-bending).

Micro RNAs (miRNAs)

Short segments of RNA that can either burst apart mRNA or block translation.

Point mutation

Substitution of one base for another.

Frameshift mutation

Adding or removing a nucleotide, shifts everything after.

Silent mutation

No change in amino acid.

Missense mutation

Mutation that leads to a different amino acid.

Nonsense mutation

Occurs when a stop codon appears where it shouldn’t.

Polymerase Chain Reaction (PCR)

Produces many copies of a target template DNA sequence.

Gel electrophoresis

Separates DNA fragments based on their size.

DNA cloning:

Makes many copies of a DNA fragment of interest.

Enzymes

Speeds up chemical reactions.

Induced fit

Enzyme changes shape slightly when it binds to its substrate.

Competitive Inhibition

Decreases reaction rate when there are less substrates.

Noncompetitive inhibition

Enzymatic reaction will never reach its max rate regardless of available substrate.

Glycolysis

Glucose broken down into 3 carbon molecules in the cytoplasm.

Krebs cycle

Occurs in mitochondrial matrix, producing ATP, NADH, and FADH2.

Oxidative phosphorylation

ETC in inner mem of mitochondria, lowers free energy in small amounts.

Fermentation

Occurs in cytoplasm, anaerobic pathway for breaking down glucose when oxygen is used up, creating few ATP.

light-dependent reactions

Takes place in thylakoid membrane.

Calvin cycle

Carbon fixation in the stroma, uses ATP and NADPH to convert CO2 into sugar.

Entropy

Measure of molecular disorder.

1st law of thermodynamics

Energy can't be created nor destroyed, only transformed.

2nd law of thermodynamics

Energy transformations increase entropy of universe.

Apoptosis

Programmed cell death

G1 checkpoint

Primary checkpoint in which cells decides to divide, check cell size, nutrients, growth factors, and DNA damage

G2 checkpoint

Make sure division goes smoothie, check DNA damage + DNA replication completeness

Ligands

Molecules that bind specifically to other molecules, receptors

Autocrine

cell signals itself, ligand binds to receptor on its own surface

Paracrine

Cell communicates over relatively short distances

Endocrine

uses circulatory system as a distribution network

Synaptic

nerve cells transmit signals

Innate Behaviors

Predicted and performed similarly across members of same species

Learned Behaviors

Animals, mainly primates, capable of problem-solving & construction of mental maps

Exponential growth

populations growth rate stays the same regardless of population size, J shaped curve

Logistic growth

populations growth gets smaller as population size approaches carrying capacity, S-shaped curve

Cyclical oscillations

repeated rise and drops in size of population over time

Carrying capacity

maximum number of individuals an ecosystem can support

Competition

(-/-) species compete when they have overlapping niches

Predation

(+/-) one species, predator, kills and eats individual of other species, prey

Mutualism

(+/+) both interacting species benefit

Commensalism

(+/0) benefits individuals of one species without harming or helping individuals of the other species

Parasitism

(+/-) parasite gains something while the host loses something

Invasive species

species that have been introduced to areas outside of the native range, they may outcompete native species for resources, altering community structure

Keystone species

often predators and they hold a community together and keep other species stable. Removal of keystone species can drastically impact other species

Prokaryotes

Dna is circular, free floating in cytoplasm, No nucleus + membrane bound organelles, Small (1-5 micrometers), Always unicellular, ex: bacteria, archaea

Eukaryotes

Dna is linear, found in the nucleus, Has nucleus & membrane bound organelles, Larger (10-100 micromolecules), Can be unicellular or multicellular, ex: animals, plants, fungi, protists

Endosymbiotic theory

how eukaryotic cells evolved from prokaryotic cells

phospholipid bilayer

amphiphilic nature, polar hydrophilic head + non polar hydrophobic tail, creates basic structure of the membrane + acts as barrier to most water soluble molecules

Integral proteins

embedded in phospholipid bilayer & extend all the way across the membrane, contains at least one hydrophobic region that anchors them to core of bilayer

Passive transport

transport that doesn't require energy

Active transport

transport the required input of energy to occur

Endocytosis

term for various types of active transport that moves particles into cell by enclosing them in a vesicle made of plasma membrane

Exocytosis

form of bulk transport where materials are transported outside of cell in membrane bound vesicles that fuse with plasma membrane

Hypotonic

solute concentration is lower than cell concentration, net flow of water INTO cell, cell gains volume

Isotonic

solute concentration same as cell, no net nonevent of water into or out of cell, volume remains the same

Hypertonic

greater solute concentration than cell, net movement of water OUT of cell, cell loses volume

Meiosis

The specialized type of cell division that reduces the chromosome number by half, resulting in four haploid cells

Mendel’s laws

Law of Segregation AND Independent assortment

Law of Segregation

During meiosis the alleles for a trait separate, so each gamete only gets one allele

Independent assortment

During meiosis, alleles for one trait separate independently from other pairs of alleles, allowing for all possible combinations

Non-Mendelian inheritance

Codominance, Incomplete dominance, Pleiotropy, Epistasis, Multiple alleles, Sex-linked, Polygenic Inheritance, Linked genes

Codominance

both alleles/phenotypes are being expressed

Incomplete dominance

Heterozygous genotype, shows a blend of traits

Pleiotropy

single gene contributes to multiple characteristics