Mod 1 Quiz (SG) Flashcards
adaption
a change or the process of change by which an organism or species becomes better suited to its environment
adaptive radiation
ecological niche and rapid diversification fills niches
allele
version of a gene that directs the production of a form of the protein that produces a specific trait (ex. yellow)
allele frequency
the proportion of one specific allele compared to the total number of alleles in a population (add up to be 100%)
allopatric speciation
biological populations become geographically isolated from each other and effects reproduction between the species
amino acids
molecules that combine to form proteins
anticodon
matching code located at the end of tRNA that fits with the mRNA
ancestral trait
(old) present in more distant common ancestor(s) of the group
base pair
consists of two complementary DNA nucleotide bases that pair together to form the DNA (ex: A and T)
biological species concept
a species taxon as a group of organisms that can successfully interbreed and produce fertile offspring
chromosome
holds protein and DNA
codon
a sequence of three nucleotides which together form a unit of genetic code in a DNA or RNA molecule.
crossing over
the exchange of DNA between paired homologous chromosomes (one from each parent) that occurs during the development of egg and sperm cells (meiosis)
derived trait
(new) evolved in the most recent common ancestor of the group
diploid
2 complete sets of chromosomes
dominant trait
inherited traits that, when presented, are expressed (ex: DD, Dd)
ecological species concept
a set of organisms adapted to a particular set of resources, called a niche, in the environment
founder effect
random chance that this group leaves (ex: amish community)
frameshift
a genetic mutation caused by a deletion or insertion in a DNA sequence that shifts the way the sequence is read
gamete
reproductive cells (ovum[egg], sperm) –> haploid = 1 copy of each chromosome, human = 23 chromosomes not paired
gene
basic physical and functional unit of heredity
genetic bottleneck
random sampling of survivors; population growth (ex: different allele frequencies in post-tornado population)
genotype
the specific make up of a trait (Yy, yy, YY)
gene flow
the movement of alleles among populations through interbreeding
genotype frequency
the proportion of a population that possesses a particular genotype
gene pool
all of the alleles in a population
haploid
a cell that contains a single set of chromosomes
heterozygous
two different alleles present at the same time (Yy)
homology
the state of having the same or similar relation, relative position, or structure (ex: forearms in mammals)
homoplasy
the development of organs or other bodily structures within different species, which resemble each other and have the same functions, but did not have a common ancestral origin (ex: panda’s “thumb”)
homozygous
two of the same alleles present at the same time (YY, yy)
hypothesis
a concept or idea that you test through research and experiments
independent assortment
different genes independently separate from one another when reproductive cells develop
locus
the physical location of a gene/allele on a strand of DNA (ex: page number of the recipe)
microevolution
changes in the frequencies of alleles within a population
monohybrid cross
a breeding experiment in which the parents differ in only one genetically determined trait that creates an opposite phenotype (mendel) (ex: PP and pp = PP and Pp)
mRNA (messenger RNA)
creates mirror image of DNA bases and moves the message to the ribosome
mutation
changes in an individual’s DNA sequence
nucleus
contains DNA
nucleotide
sugar molecule and phosphate molecule, one of four bases - GTCA
occam’s razors
when two hypothesis have the same predictions and available data cannot distinguish between them, the more simple solution is likely to be correct
parapatric speciation
a smaller population is isolated from a larger group, and becomes differentiated to the point of becoming a new species (cannot reproduce with the original population)
phenotype
the physical expression of the genes or what we see (ex: hair color)
phylogeny
evolutionary history of organisms and their relationships based on evidence of common ancestry (diagram: branching of species from common ancestors → tree-like in form)
pleiotropy
one gene influences more than one trait
polygenic traits
characteristic influenced by one or more gene (ex: height)
population
the number of organisms in a certain area
prediction
a statement about a future event or future data
principle of segregation
describes how gene variants are separated into reproductive cells (different expressions of a trait are controlled by discrete units that occur in pairs, separation of the pair during reproduction, offspring inherit one unit from each parents, during fertilization the pairs reunite to determine the expression of the trait in the offspring)
sister chromatid
exact replicas, resulting from duplication
somatic cell
liver cells, nerve cells, muscle cells (diploid = 2 copies of each chromosome; humans: 23 pairs of chromosomes, 46 total)
recessive trait
not expressed if there is a dominant allele at the same locus (must be two alleles of the same recessive trait to express the trait (y))
ribosome
protein synthesis (bind messenger RNA and transfer RNA to synthesize polypeptides and proteins)
theory
a hypothesis that has received overwhelming support through repeated studies
transcription
mRNA winds itself into the DNA in the nucleus
translation
the process through which information encoded in messenger RNA (mRNA) directs the addition of amino acids during protein synthesis
tRNA (translation RNA)
links amino acids together to form a protein in the ribosome
typological species concept
a species defined by its fixed, unchanging properties
mitosis
cell division that gives rise to genetically identical cells in which the number of chromosomes is maintained (diploid) ; splits once
meiosis
special type of cell division that reduces the chromosome number by half, creating four haploid cells, each genetically distinct from the parent cell that gave rise to them ; splits twice
darwin’s theory of adaptation
an organism’s feature that was functionally designed by the process of evolution by selection acting in nature in the past
variation
the difference in DNA among individuals or the differences between populations among the same species
convergent evolution
different species but similar ecological niches and adapt in similar ways because of similar pressures (ex: flight between bats and hawk is very different but overall they are accomplishing the same goal)
heredity
the passing of characteristics from one generation to another
gregor mendel (experiments)
plant hybrids (1865), first to trace characteristics of successive generations of living things, peas, different traits inherited independently
polygenetic inheritance
multiple genes for one trait, includes most traits of the skeleton, traits are continuous, rather than discrete
phenylketonuria (PKU)
absence of enzyme that converts phenylalanine to tyrosine
proteins
- structural
- antibody
- enzyme
- messenger
- transport
enzyme
carry out chemical reactions, metabolism
antibody
bind to foreign elements, protection
primary amino acid sequence
fold to form functional proteins
DNA vs RNA
DNA = storing and transferring genetic information, RNA = directly codes for amino acids and as acts as a messenger between DNA and ribosomes to make proteins
human chromosomes
23
homologous chromosomes
same size and contain DNA that codes for the same traits (ex: eye color), but can contain different alleles
genetic variation
- mutations are the only source of new alleles
- evolution is only possible because of mistakes made when replicating DNA
point mutations
a change in one base (only affects one codon set): ex: sickle cell anemia
insertion mutation
a base is inserted into a sequence and causes a fragment shift (all codon sets after the insertion are changed): ex: crohn’s disease
deletion mutation
a base is deleted, causes a fragment shift (changes all codon sets with/after the deleted one): ex: cystic fibrosis
inversion mutation
a portion of DNA is flipped (codon set is inverted)
fitness
the relative ability of an organism to survive and transmit its genes to the next generation → how many offspring one has in their lifetime
genetic drifts
random changes in allele frequency over time
speciation
the process by which new species arise from existing ones
sympatric speciation
no geographic separation, different morphs (or behavior) that are equally successful
ecological niche
the way an organism “makes a living”
convergence
due to similar environmental pressures, natural selection produced similar adaptations in species from different evolutionary lineages
outgroup
closely related group outside the study group (ex: dog in lab)
taxonomy
the classification of something, especially organisms
the comparative method
seek evidence for adaptive evolution by investigating how the characteristics of organisms, such as their size, shape, life histories, and behaviors, evolve together across species
evolution
the change in the heritable characteristics of biological populations over successive generations
blended characteristics
casual observations (fur color or body size) led to this idea → this would remove any variations in population (everything would look the same)
