In mice, a short-tailed mutant was discovered. When it was crossed to a normal long-tailed mouse, 4 offspring were short-tailed and 3 were long-tailed. Two short-tailed mice from the F1 generation were selected and crossed. They produced 6 short-tailed and 3 long-tailed mice. These genetic experiments were repeated three times with approximately the same results. Part A Indicate whether short tail would be dominant or recessive.

The short tail progeny in the mice crossing has been found to be the dominant phenotype.

The cross between the short tail ad a long tail mice has resulted in half of the progeny being more short-tailed. The cross with the heterozygous genotype has resulted in the 1:1 ratio of the dominant and the recessive traits.

The F1 progeny has more the number of short-tailed mice concerning the long-tailed has been the representation of the short-tailed parent to be heterozygous and dominant.

The short-tailed mice are crossed and resulting in more than half of progeny being short tailed. This has been the demonstration with short-tailed progeny being dominant,

In mice genetic cross, the short tail progeny is dominant.

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Dominant

Explanation:

Let the allele for short tail trait be represented by "T" and allele for long tail trait be represented by "t"

When a short tailed  mutant with genotype "tt" is mated with long tailed mouse, following offspring will be produced -

Tt * tt

Tt, Tt, tt, tt

so the ratio of short tailed and long tailed mouse is  1:1

Here it is given as 4:3 . Hence, there are chances that short tail trait is dominant

In the second generation , two short tailed mouse are crossed. The following offspring will be produced

Tt * Tt

TT, Tt, Tt, tt

The ration of short tailed and long tailed mouse is 3:1

Here it is given as 6:3 i.e 2:1  . Hence, short tail trait is dominant over long tail trait.