please show as simply as possible how the answers are obtained. In goats, the pr
ID: 257305 • Letter: P
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please show as simply as possible how the answers are obtained.
In goats, the production of beards occurs because of an autosomal gene that is dominant in males and recessive in females. We will use the symbol B for the beard allele and B for beardless allele. Another independently assorting autosomal allele produces a black coat (W) that is dominant to white coat (w). Based on the cross, B' B Ww (male) x B B Ww (female), answer the following questions: a. Give the proportion of the observed male progeny that one expects to have beards and black coats. b. Give the proportion of the observed female progeny that one expects to have beards and white coats. c, What is the term that describes this inheritance pattern? In gene interaction: (True or False. Please write the word true or the word false) a. Multiple independently assorting genes and their alleles interact to produce b. Multiple genes and their alleles interact to yield typical Mendelian phenotypie c. Epistasis only results from a recessive "loss-of-function." novel phenotypes ratios. Epistatic relationships between genes ultimately result from the interaction of gene products. d. Genes A, B and C are independently assorting and control the production of a black pigment according to the pathway below: Assume that an individual with black pigment and genotype Ambbee mates with a colorless individual, aabbce, to give a black Fi. The Fi is selfed and produces 500 F progeny How many would exhibit a black pigment? What is the probability of a colorless offspring with genotype aabbCe? a. b.Explanation / Answer
ans1
given, beard producing gene is dominant in males and recessive in females and black coat is dominant over white.
parental genotype= BbB+ Ww (male; beard+black coat) X BbB+ Ww (female;beardless)
from above table we can calculate the asked proportions:
(a) males with the black coat and beard= 9/16
(b) females with beard= 0/16 less likely to have the beard because the gene for the beard is recessive in females
(c) this is the sex-limited trait as the character is influenced by sex
ans 2- both a and b are true, assortment of alleles result in novel phenotype
c- false, epistasis can result either from the gain of function or loss of function mutation
d- true, product interaction affect the phenotype
ans 3- AABBCC (BLACK) X aabbcc (COLORLESS)
F1- AaBbCc (all Black)
AaBbCc X AaBbCc
gametes= ABC, ABc, Abc, AbC, abc, aBC, abC, aBc
a) from cross- 42/64; completely black= 1/64
b) colourless- 22/64; completely colourless= 1/64
GAMETES BbW Bbw B+W B+w BbW BbBbW W BbBbW w B+BbWW B+BbWw Bbw BbBbW w BbBbww B+BbWw B+Bbww B+W B+BbWW B+BbWw B+B+WW B+B+Ww B+w B+BbWw B+Bbww B+B+Ww B+B+wwRelated Questions
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