Question

How many different kinds of gametes will be produced by a plant having the genotype AaBbCC?
(a) Two
(b) Three
(c) Four
(d) Nine

Answer 1

Hint: The number of gametes formed is related to the number of heterozygous alleles. This can be determined using the fork line method.

Complete answer:
The number of gametes that will be formed can be understood by the number of heterozygous alleles. In genotype AaBbCC a total of four gametes will be formed on meiosis which will include alleles ABC, aBC, AbC, and abC. This can also be done using the formula ${ 2 }^{ n }$ where n is the total number of heterozygous alleles present. This is because the alleles are separated during gametogenesis and only one type of allele of a particular gene can be present within the gamete. So suppose that the genotype is YyZzDd then eight types of gametes will be formed and three heterozygous alleles are present.
- The idea that paired germinal units or factors are inherited from one generation to another was proposed for the first time by Mendel.
- He is known as the ‘Father of Genetics’
- He performed monohybrid and dihybrid crosses on pea plants and gave the principle of dominance, the principle of paired factors, and the law of independent assortment.
- Mendel’s laws were not applicable in several cases like incomplete dominance, multiple alleles, codominance, linkage, etc.
- Mendel didn’t find any exceptions during his experiments as he worked on genes that were not linked and were inherited separately.
Importance of Mendel's Laws:
- It has helped enormously in improving plant breeding techniques.
- The development of highly productive and disease- resistant varieties have been made possible.
- Helped in developing improved animal varieties also in animal husbandry.
So, the correct answer is,” Four different types of gametes will be produced by a plant having genotype AaBbCC.”

Note: It is important to know about the concept of pleiotropic genes and polygenic inheritance. A pleiotropic gene is where a single gene is responsible for the expression of multiple characters. In polygenic inheritance, multiple genes are responsible for the expression of a single character.