Foundations of Bio Test 3

interphase

a long period when cells are not dividing

mitotic phase

a short period when cells physically separate; DNA condenses and is divided equally into 2 cells

DNA helicase

separates the strands of the double helix in initiation

ssBinding Proteins

stabilizes single strands of DNA to prevent unwanted hydrogen bonds between basepairs in initiation

topoisomerase

relieves strain cause by unwinding a twisty molecule

primase

lays down an RNA primer in order to give polymerase a place to start elongating and binding to

elongation

DNA polymerase binds and adds complementary DNA bases to 3’ end of new strand

template strand

existing strands of DNA determines sequence of new strand; read 3’ to 5’

histones (function in mitotic phase)

organize DNA in the nucleus

cytoskeleton function in mitotic phase

mediates movement of chromosomes

cytokinesis

division of cytoplasm

telomeres

act as a buffer for chromosomes following DNA replication

hayflick limit

average number of times a normal human cell population will divide before becoming senescent and dying

telomerase

an enzyme containing an RNA primer and restores telomere length; maintains replicative capacity of cells; activity extinguished during embryonic differentiation in humans

cancer

disease of the cell cycle

quinolones

inhibit topoisomerase (and other DNA stabilizing proteins) to disrupt DNA synthesis

taxol

destabilizes microtubules to stop cell division during M phase

stathmin

promotes depolymerization and prevents polymerization

genome

all the chromosomes in the nucleus of a cell; contains all protein making info for an organism

karyotype

number and visual appearance of the chromosomes in the cell nuclei off an organism

phenotypes

characteristics of an organism based on genetic info (words)

kinetochore

attaches to centromere to pull sister chromatids apart

centromere

where sister chromatids are attached

gene

coding regions of DNA; code for mRNA that is made into proteins

homologous chromosomes

contain the same genes in the same location, but have different version of the genes; come our parents (one from maternal, one from paternal)

gene locus (plural loci)

the location of a specific pair of genes

alleles

alternative versions of the same gene, in pairs

genotype

which alleles are present at a gene locus (letters)

gametes

required for sexual reproduction; have half the number of chromosomes of a regular cell; fuses with another to create new organism

ploidy

number of sets of chromosomes in a cell

haploid cell

1n (gamete)

diploid

2n (somatic/ body cell)

meiosis

2 rounds of cell division for going from diploid to haploid

asexual reproduction

one organism can make genetic clones; all end up the same

sexual reproduction

two gametes required; creates genetic variation

principle of independent assortment

different genes assort independently because 1. they are located on different chromosomes and 2. these chromosomes have 2 equally likely ways of lining up before they are segregated

monohybrid cross

cross of 1 gene

reciprocal cross

flipping maternal and paternal genotypes to see if it makes a difference

dihybrid cross

cross of 2 genes

test cross

homozygous recessive parent crossing with parent with dominant phenotype but unknown genotype

hemizygous

genotype of males (XY)

sex-linked genes

genes on the X chromosome that impact male and female progeny differently

linked genes

genes on the same chromosome that will be inherited in parental arrangement more often than recombinant arrangement and is determined by map distance

dominance patterns

codominance and incomplete dominance do not follow a simple dominant and recessive allele pattern; heterozygotes have a unique phenotype

codominance

heterozygotes show both alleles; neither is dominant (ex. blood type)

incomplete dominance

heterozygotes have intermediate phenotype different from either homozygote (ex. flower colors)

epistasis

two genes interact to produce phenotype (ex. chicken crests)

spindle apparatus

part of cytoskeleton