Bio 101

null hypothesis

x does not effect y

alternate hypothesis

x does effect y

jean baptiste lamarck

first to propose a formal theory of evolution

transitional feature

a trait in a fossil species that is intermidiate between those of ancestral and drived species

vestigial trait

a reduced or incompletely developed structure that has no or reduced function, but is clearly similar to functioning organs or structures in an ancestral or closely related species

phylogenetic tree

a branching diagram that depicts the ancestor-descendant relationships among species or other taxa

homology

a similarity that exists in species due to common ancestry

genetic homology

similarty that occurs in DNA nucleticle sequences, RNA nucleotide sequences, or amino acid sequences

developmental homology

similarty in developmental structures or processes

structural homology

a similarity in adult morphology or form

speciation

a process that results in new species being formed from pre-existing species

darwins first potulate

variation happens in idividual organisms that create a population

darwins second postulate

some of the traits can be pasted down

darwins third postulate

survival and reproductive success are highly likely

darwins fourth postulate

the number of individuals that survuve best and create the most offspring is not a random sample of the population

biological fitness

the ability of an individual to produce surviving, fertile offspring relative to that ability in other individuals in the population

natural selection

The force affects individuals’ selection, favors individuals with higher fitness

adaptation

variation in a trait that increases fitness of an individual

divergent evolution

ancestor population is divided and each evolves seperatly

aclimatization

A change in an individual’s phenology that occurs in response to a change in natural environmental conditions is not passed down

fitness trade off

a compromise between two traits that cannot be optimized simultaneously

genetic correlation

when selections on one trait cause a change in another trait

chromosome

consists of a single long DNA double helix around proteins, called histenes

gene

a region of DNA in a chromosome that codes for a particular protein or RNAc

cromatid

each of the double stranded DNA copies in a replicated chromosome

sister chromatid

chromatid copies that remain attached at their centromere

heredity

the transition of traits from one generation to the next

DNA

string of nucleic acids that carry information responsible for the development of heritable traits

genome

all of DNA of an organism

eukaryotes

organisms that have membrane, enclosed nucleus and organelles

haploid

has one set of chromosomes

diploid

has two sets of chromosomes

homologous chromosomes

a pair of chromosomes in diploid organisms

allele

alternate form of a gene for a trait

locus

where the gene is located

asexual reproduction advantages

offspring retain parents adaptations, reproduction is fasteras

asexual reproduction

offspring is identical to parent and one another

asexual reproduction disadvantages

low genetic veritably

interphase

90% of life

mitosis

seperation of chromosomes

cytokenesis

division of cell

prophase

chromosomes condense, spindle apperatus begins to form, nucleus breaks down

metaphase

chromosomes migrate toward center of cell

anaphase

sister chromatids separate, pulled to opposite poles of spindle apparatus

telophase

nuclear envelope reforms, chromosomes decondense

sexual reproduction

genetic material from two parents is combined in offspring

sexual reproduction disadvantages

may lose or gain disadvantageous adaptations of parent, slower

sexual reproduction advantages

more variation in offspring, better chance of some offspring surviving harsh conditions

prophase I

homologous chromosomes pair up to form tetrad

metaphase I

tetrads align along metaphase plate

anaphase I

tetrads separate, sister chromatids go together

meioses II

sister chromatids in each daughter cells are spilt into two more cells

autosomal inheritance

the patterns of inheritance on genes not on sex chromosomes

phenotype

an individuals observable traits

homozygous

having two of the same allele

heterozygous

having two different alleles

dominate allele

an allele that produces the same phenotype in heterozygous and homozygous genotype

recessive allele

an allele that produces its phenotype only in homozygous genotypes

pure line

individuals identical in phenotype that when crossed produce offspring that all have the same phenotype

hybrid

offspring from crosses between homozygous parents with different genotypes

polymorphic

a trait that appears commonly in two or more different forms

reciprocal cross

a cross in which the phenotypes of the male and female are reversed compared with a prior cross

test cross

a cross of a homozygous recessive individual and an individual with the dominat phenotype but unknown genotype

x-linkage

referring to a gene located on the x chromosomes or a trait associated with a gene on the x chromosome, also known as x-linked

y linkage

referring to a gene located on the y chromosome or a trait associated with a gene on the y chromosome, also called y-linked