Answer to Question #152034 in Genetics for Hailey

Question

In rabbits straight ears are dominant to floppy ears. Black eyes are dominant to red eyes. Two rabbits are crossed. SSBB x ssbb what are the parents phenotypes

Answer 1

Phenotype: It is the observable trait in an individual because of the genetic makeup for that trait. Like here, the phenotype i.e. the observable trait in the rabbit are floppy ears, red eyes, etc.

Genotype: It the genetic constituent present in an individual that is responsible for causing a particular trait. For example: here the genotype for floppy ears is 'ss' and genotype for red eyes is 'bb'.

Dominant: When an allele is capable of expressing itself and masks the action of another allele in case of heterozygous condition. For example: straight ears is dominant to floopy ears as : 'S' allele is dominant to 's' allele. Therefore, SS/Ss will result in dominant phenotype (straight ear).

Recessive: When an allele can only express in case of homozygous condition and gets masked in case of heterozygous condition. For example: the recessive phenotype (floppy ears) can only express in 'ss' condition.

Now, look at the given question:

1. SSBB: This genotype has all the dominant alleles. So, phenotype expressed is also dominant. Hence, the phenotype is Straight ears and black eyes.
2. ssbb: This genotype contains all the recessive alleles. So, the phenotype expressed is also recessive. Hence, the phenotype is floppy ears and red eyes.

The answer is :

The phenotype of 'SSBB' is Straight ears and black eyes and the phenotype of 'ssbb' is floppy ears and red eyes.