Horniness in sheep is a sex-dependent sign. In sheep, the H gene determines the development of horns, the H ‘gene – the absence of horns. Males with genotypes HH and HH ‘are horned. Having the HH genotype, females can be horned, and heterozygous females – hornless.
1) What genotype can animals have:
a) horned ram;
b) a hornless ram;
c) horned sheep;
d) a hornless sheep?
2) What offspring can be expected from the following crosses:
a) (women) НН’ХХ х (husband) H’H’XY;
b) (women) ННХХ х (husband) HH’XY?
1) a) HHXY, HH’XY; c) NHXX;
b) H’H’XY; d) NN’XX, N’N’XX.
2) a) in F1 hornless females, hornless males and horned males in a ratio of 2: 1: 1;
b) in F1, horned females and males in a 1: 1 ratio.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.