Imagine that two unlinked autosomal genes with simple dominance code in goats for size, where T is tall and t is short, and for

Answer:

(A) 0.0625

(B) 25%

Explanation:

A

With the following:

T indicates tall

t indicates short

R indicates red

r indicates tan.

When a short tan male goat mates with a tall red female goat of an unknown genotype;

Let's analyze separately;

A short tan male goat = ttrr

The female goat’s genotype is not specified but it is known to be tall and red

∴ We determine that she must be T_ R_;

the potential genotype probability of the female for each allele could be:

- T

or Tt- RR

r

Nonetheless, from earlier discussion;

the chance that the female is Tt =

the probability of the female being Rr =

the probability of passing on the recessive allele 't' to offspring =

the probability of passing on the recessive allele 'r' to offspring =

∴ the likelihood that the pairing would yield short, tan offspring (ttrr) stands at;

=

=

= 0.0625

(B)

In pea plants, one is homozygous recessive for both traits, leading to the cross of Yy Rr × yy rr. Determine the green and round offspring percentage.

For Color, let:

Y = Yellow

y = Green

For shape, let;

R = Round

r = wrinkled

If a cross occurs between Yy Rr × yy rr. (yellow round and green wrinkled)

the ratio of green and round offspring will be;

If Yy Rr self-crosses; various traits (YR, Yr, yR, yr)

                   YR                    Yr                    yR                    yr

yr                 YyRr                 Yyrr                 yyRr                 Yyrr

yr                 YyRr                 Yyrr                 yyRr                 Yyrr

                   Yellow              Yellow            Green              Green

                   Round               Wrinkled        Round              Wrinkled

                   Thus, the percentage of green and round offspring based on the above is:

=

=

=