MICROBIO 303 Exam questions and answers graded A+

MICROBIO 303 Exam questions and
answers graded A+
Dominance led mendel to conclude that while they looked identical, ____ and ____ plants differed
genetically - ANS✅✅P1 & F1



It's important to make a distinction b/w an organism's appearance and... - ANS✅✅it's genetic
makeup



Which of mendel's plant generations has the same phenotype? - ANS✅✅P & F1



F2 phenotypic ratio - ANS✅✅3:1



F2 genotypic ratio - ANS✅✅1:2:1



mendel already concluded that male & female genes contribute ____________ to traits of offspring -
ANS✅✅equally



simplest explanation is that there are ___________ for seed shape gene - ANS✅✅2 alleles



Mendel noted that gene number doesn't double every generation, so.... - ANS✅✅he reasoned
that gene pairs segregate



Principle of Segregation (Mendel's First Law) - ANS✅✅Principle of heredity discovered by Mendel
that states that each diploid individual possesses two alleles at a locus and that these two alleles
SEPARATE when gametes are formed, one allele going into each gamete.



mendel's reasoning allowed him to predict... - ANS✅✅F2 genotypes



mendel confirmed predictions through... - ANS✅✅5 successive generations



Mendel accurately identified alternative forms of... - ANS✅✅a gene (alleles)

,organisms with identical alleles for a gene - ANS✅✅homozygous



organisms with different alleles for a gene - ANS✅✅heterozygous



*know how to perform a dihybrid cross* - ANS✅✅



next, mendel examined a pair of differing traits using... - ANS✅✅a dihybrid cross



dihybrid cross phenotypic ratio - ANS✅✅9:3:3:1



*notice that the _____ ratio is still present for each trait in a dihybrid cross* - ANS✅✅3:1



Principle of Independent Assortment (Mendel's 2nd Law) - ANS✅✅alleles are distributed into
gametes randomly during meiosis



*Mendel's 1st law deals with...* - ANS✅✅1 gene, 2 alleles



*Mendel's 2nd law deals with...* - ANS✅✅2 genes, 2 alleles



Principle of Independent Assortment explains the inheritance of... - ANS✅✅2 traits



Mendel assumed that alleles of one gene pair (ex: smooth vs wrinkled) segregate into gametes
independently of... - ANS✅✅the alleles of other gene pairs (ex: yellow vs green)



resulting gametes have... - ANS✅✅all combinations of alleles



when F1 for a dihybrid cross is crossed, there are ____ phenotypic combinations now possible -
ANS✅✅4



mendel published his results after ___ years of work - ANS✅✅10



by 1900 it became obvious that... - ANS✅✅genes and chromosomes have much in common

, gene & chromosome similarities - ANS✅✅-occur in pairs (allele pairs vs homologous pairs)

-members of pairs separate during meiosis

-members of pair independently assort from other pairs



we now know genes are located on... - ANS✅✅chromosomes



how many genes do humans have - ANS✅✅20000-25000



not all chromosomes have the same number of genes. example? - ANS✅✅chromosome 19 is the
most gene-dense



incomplete dominance - ANS✅✅the expression of a phenotype that is intermediate to those of
the parents



incomplete dominance may appear to be... - ANS✅✅blending



ex of incomplete dominance - ANS✅✅white snapdragons + red snapdragons = pink snapdragons



while phenotypes are complex, the genotypes in incomplete dominance instances... -
ANS✅✅strictly follow Mendelian inheritance



in incomplete dominance, 2 or more dominant alleles give an... - ANS✅✅intermediate phenotype



we know if something is incomplete dominance by: - ANS✅✅crossing F1xF1 (parent traits come
back)



over ______ traits have been found to follow Mendel's laws in humans - ANS✅✅5000



albinism: homozygous recessive individuals can't make melanin, but if one dominant melanin allele
is carried... - ANS✅✅enough melanin can be made to have colored skin, hair, eyes



2 heterozygous individuals have __% chance of albinism per pregnancy - ANS✅✅25