BIO 202 Exam 1 vocab

Nucleotides

organic molecules that are the subunits that form nucleic acids. composed of a nitrogenous base, a five-carbon sugar (ribose or deoxyribose), and at least one phosphate group.

DNA

genetic material that provides a blueprint for the development and function of living things

RNA

single stranded genetic material. Can have multiple functions

Proteins

biological molecules consisting of one or more chains of amino acids, ultimately becomes phenotype

Transcription

DNA makes RNA.

Translation

mRNA is read by a ribosome to form a protein

Genes

stretches of DNA that code for polypeptides, proteins, and ultimately phenotypes, the basic unit of inheritance

Central Dogma

two step process of transcription and translation by which the information in genes leads into the formation of proteins

Allele

variation of a gene

Genotype

the genetic composition of an individual

Chromosome

organized structure that consists of DNA and other proteins

Prions

mis folded proteins that can transmit their shape onto normal proteins

Mitosis

cells replicate

Meiosis

cell division to make gametes

How does Meiosis cut the ploidy level

in half

What are the properties of life?

cells and organization, energy use/metabolism, environmental change response, homeostasis regulation, growth and development, reproduction, evolution

Homeostasis

maintenance of a relatively stable internal environment

Cell Theory

Organisms made of cells are the smallest units of life and come from pre-existing cells via division.

Metabolism

set of chemical reactions that happen in the cells of living organisms to sustain life

Reproduction

generation of new individuals that includes transmission of genetic material

Evolution

the change in the genetic composition of a population of organisms over time

When did earth form?

4.55 billion years ago

Water appeared on earth…

4 billion years ago

stromatolites appear…

3.5-3.7 billion years ago

4 ways life originated

nucleotides and amino acids were produced, nucleotides were polymerized to form DNA and RNA (amino acids polymerized and form proteins), polymers became enclosed in membranes, cellular characteristics arose

Prebiotic soup

medium formed by slow accumulation of organic molecules prior to the existence of life

Who used a chamber apparatus to stimulate atmosphere and bolts of lightning to form precursors, amino acids, sugars, and nitrogenous bases?

Stanley Miller

Formation of nucleic acid polymers, peptides, and polypeptides seen on

clay surface

Liposome

spherical vesicle having at least one lipid bilayer

Protobiont

an aggregate of prebiotically produced molecules and macromolecules, have acquired a boundary to maintian internal chemical environment from surroundings

Four characteristics of a protobiont

boundary separation, informational polymers, enzymatic function, self-replication

three key RNA functions

ability to store information, capacity for self-replication, enzymatic function (ribozymes)

What is less likely to suffer mutations and is more stable?

DNA

true or false: proteins have poor catalytic potential and efficiency

false

Microevolution

changes in a single gene in a population over time

Macroevolution

formation of new species or groups of species

Species

groups of related organisms that share a distinctive form

Population

members of the same species that are likely to encounter each other and thus have the opportunity to interbreed

Who realized that some animals remain the same while others change? Hint: Think of inherited characteristics like a giraffes neck

Jean-Baptiste Lamarck

Catastrophism hypothesis

catastrophic events lead to change in geological structure

Uniformitarianism hypothesis

slow geological processes lead to substantial change, Earth was much older than 6,000 years

Who says that only a fraction of any population will survive and reproduce

Thomas Malthus

Voyage of the Beagle was from ____ to _____

1831-1836

What did Darwin notice in his studies?

distinctive traits of island species that allowed them to better exploit their environment

What famous example is associated with Darwin’s observations?

Galapagos island finches

What did Darwin see in the Galapagos Island finches?

similarities in species yet noted differences that provided them with specialized feeding strategies

Who sent Darwin an unpublished manuscript proposing many of the same ideas?

Alfred Wallace

Descent with modification

all species, are descended from common ancestors but have undergone change over many generations

What is evolution based on?

Variation and natural selection

Natural selection

survival or reproduction caused by interactions between the individual and organisms and environment that increase an adaptive trait in a population

Trait

distinct variant of physical characteristic of an organism

Adaptation

any heritable behavioral, morphological, or physiological trait of an organisms that evolved by natural selection or increases the fitness of an individual in an environment

Fitness

proportionate genetic contribution individual makes to future generations

qualitative trait

trait determined by interactions at one gene and can be described by discrete categories

quantitative trait

trait that is continuously distributed due to interactions among genes and can be influenced by the environment

dominant allele

always expressed

recessive allele

only expressed in the absence of the dominant allele

directional selection

individuals at one extreme of a phenotypic range have greater reproductive success in a particular environment

stabilizing selection

favors the survival of individuals with intermediate phenotypes and selects against those with extreme phenotypes

disruptive selection

selection against intermediate phenotypes and for extreme phenotypes

balancing selection

a type of natural selection that maintains genetic diversity in a population

heterozygote advantage

selection favors the heterozygote over the homozygotes

negative frequency dependent selection

selection favors the less frequent genotype, the fitness of a genotype decreases when its frequency becomes higher

sexual selection

individuals with certain traits are more likely to engage in successful reproduction than other individuals

intrasexual selection

members of same sex directly compete with each other for the opportunity to mate

intersexual selection

mate choice- one sex chooses to mate based on characteristics of member of the opposite sex

mutation

a permanent change in the DNA sequence of a gene

drift

changes in allele frequencies due to random chance

migration

the transfer of alleles into or out of a population

what are the five factos that influence genetic variation over time?

mutation, drift, migration, natural selection, sexual selection

Hardy Weinberg equilibrium

in the absence of the five factors that influence genetic variation, allele frequencies will not change

Allopatric speciation

occurs when some members of a species occupy a habitat that is isolated from other members

adaptive radiation

a single ancestral species has evolved into a wide array of descendant species

sympatric speciation

speciation within the same range (no geographical barrier)

polyploidy

more than 2N

isolating membrane

mechanisms that prevent interbreeding

prezygotic

prevent formation of zygote

habitat isolation

caused by geographic barrier

temporal isolation

mating at different times

behavioral isolation

mating limited due to differences in behavior

mechanical isolation

morphological features such as size or incompatible genitalia prevent mating

gametic isolation

gametes dont fuse

postzygotic mechanisms

block development of a fertile individual after fertilization has taken place

hybrid in viability

egg is fertilized, but embryo does not develop past the early stages

hybrid sterility

interspecies hybrid survives but is sterile

hybrid breakdown

hybrid is fertile, but breaks down in succeeding generations

systematics

science of biological diversity and consists of taxonomy and phylogenetics

taxonomy

hierarchial system involving successive levels: description, identification, and nomenclature, and classification of organisms

phylogenetics

reconstruction of evolutionary relationships

taxon

each group at any level

is domain the lowest or highest level

highest level

all of life belongs to one of 3 domains

bacteria, archaea, eukarya

genus name is always capitalized true or false

true

species epithet is always capitalized true or flase

false

both names either italicized or underlined true or false

true

phylogeny = cladistics

evolutionary history of a species or group of species

phylogenetic tree or cladogram

hypothesis that depicts evolutionary relationships- has branches, nodes, roots, leaves

brach points or nodes

when a species diverged into 2 or more different species (where cladogenesis occurs)

leaves

extant (existing) taxa

root

earliest common ancestor