samiam99

MSUD is a rare inborn error in metabolism ..affected individuals cannot completely degrade AA Leucine,isoleucine, valine due to lack of activity of certain degradative enzymes..accumulated degradative enzymes, keto acids are excreted in urine and sweat autosomal recessive trait. This is practice work Question 1 MSUD allele affects phenotype by altering a) The enzyme responsible for degrading valien isolecuine and lecuin**i thought this was the answer..does not make sense why is this incorrect? b) but the answer is none of the above. Question 2 which is true a)nucleotide sequence for MSUD allele is different then the nucleotide sequence for normal allele...yes this is correct b)MUSUD allele of one individual must be identical to the MSUD allele of another individual** I thought they were both correct but the answer is just a. why would b) be incorrect? example to individuals have blue eye doesn't this mean there alleles are identical same nucleotide sequence?

State how many chromosomes and chromatid are found...is this correct? spermatogenesis --------------------------------------… Primordial germ cells- 2n =46 chromosomes and 46 chromatid..because chromosomes have not yet entered s phase? spermatogonial stem cells- still 46 chromatid and 46 chromosomes primary spermatocyte- s phase has occured so 46 chromosome and 92 chromatid? --------------------------------------… oogenesis primordial germ cell= 46 chromosomes 46 chromatid oogonia- s phase has not occured?- 46 chromosomes and 46 chromatid primary oocyte- s phase has occured so 46 chromatid and 92 chromatid? ootid and the polar bodies are each haploid with 23 chromosome and 23 chromatid? --------------------------------------… Lastly angiosperm - sporophyte...assuming they are 2N=46 sporangia is the chambers where gametophytes are produced one question said number of chromosomes in the sporangium cell found on anthers - so they are referring to microsporocytes?- 46 chromosomes 92 chromatid? magasporocyte and microsporocytes=diploid 46 and 92 chromatid endosperm = 3N triploid so 69 chromosome 69 chromatid? antipodal and tube cell= 23 chromosomes and 23 chromatid flower petal and parencyma cell of the leaf- I'm assuming these are like nervous system or brain cells and are arrested in G phase so 46 chromosome and 46 chromatid?

Punnet square question? True breeding punnet square? I got the right answer but need some clearing up. true-breeding dwarf and true breeding maize plants produced all dwarf plants in F1 . in the f2 generation dwarf and tall plants segregated 3:1 ratio. Dwarf F2 plants self pollinated. what proportion of the resulting plants would be expected dwarf let BB=Dwarf bb=tall BBXbb F1= 1 Bb Bb x Bb F2=1 BB:2 Bb: 1bb now it gets tricky.. so there is a 1/3 chance that BB x BB but a 2/3 chance that Bb x Bb...what I am confused about is what about the chance Bb x BB? ......................................… if BB and BB were crosses all offspring would be BB(dwarf) 4/4=1 *1/3= 1/3 if Bb and Bb were crossed 3/4 would be dwarf so 3/4* 2/3=6/12+1/3= 10/12= 5/6 proportion expected to be dwarf?