BIO-110 Exam #3 Flashcards

genetics

study of how traits are inherited

traits

characteristics that vary between individuals

traits can be on a…

binary or continuous spectrum

what were the two theories dominated when Mendel was alive

• blending inheritance

• inheritance of acquired characteristics

blended inheritance

the idea that the traits of the parents are blended together in the offspring

inheritance of acquired characteristics

idea that traits evolve as parents chance, and the modified trait is passed to offspring

how did mendel control pollination of parents

by removing male organs

a cross (mendel)

a single breeding of diff individuals

what was the benefit of mendel picking 7 traits to focus on

they seemed to be inherited independently

hybrid

crossing two individuals w/ different traits

f1 generation hybrids

did not blend, matched one parent or the other

he let the f1 generation do what

self pollinate or he bred them w/ each other

principle of segregation

states one trait particle is donated by each parent to their offspring and these are segregated in the gametes of offspring, so each gamete only carries one “trait particle”

genotype

combination of alleles carried by a specific individual

meiosis is responsible for

segregation of genes in gametes

what does the principle of segregation say abt pairs of alleles

they are separated during meiosis I in the formation of gametes

dependent assortment

genes transmitted to offspring together

indep assortment

genes transmitted randomly to offpspring

what did mendel find about indep assortment

he found 4 diff offspring phenotypes w/ ratio of 9:3:3:1 for F2 gen

principle of indep assortment

diff gene alleles are inherited indep of each other

what are the reasons for indep assortment

1. they are located on diff chromosomes

2. these chromosomes have 2 equally likely ways of lining up before they are segregated

why are organelles only passed down from the mother

because she provides the mitochondria and or chloroplasts for egg cell

multiple alleism

a gene w/ more than two possible alleles

codominance

simultaneous expression of the phenotype of each allele present, rather than a dominant-recessive relationship

incomplete dominance

the phenotype of a heterozygote that is a mix of the dominant and recessive phenotypes

pleiotropy

when a single cell gene influences more than 1 trait

polygenic inheritance

where many genes all contribute to one trait

origin of replication

a specific sequence of bases where a new strand of DNA is built to match with the parent (or template) strand

the origin of replication creates…

a “bubble” in the double helix where the strands are separated from each other during DNA synthesis

replication fork

at one end of the “bubble” where the parental strands are separated from each other to facilitate elongation of the daughter strand

dNTPs

nitrogenous bases w/ 2 extra phosphates (which provides energy for polymerization)

dNTPs can only be added to what

to the 3’ end of a strand of DNA (to the -OH group)

what does the enzyme RNA primase do

attaches a short RNA segment (primer) to the unwound DNA strands

DNA polymerase uses the primer to do what

to bind to the parent DNA strand and begin synthesis of daughter DNA strand

DNA polymerase can only attach

nucleotides the 3’ carbon

because of the DNA polymerase only attaching nucleotides the 3’ carbon…..

the daughter strands are always created in 5’ to 3’ direction