Question
Question: Number of gamete types formed by AaBbCc individual/heterozygous for three gene loci is A)2 B)4 ...
Number of gamete types formed by AaBbCc individual/heterozygous for three gene loci is
A)2
B)4
C)8
D)16
Solution
Sperm and ova are the two most predominant gametes. These two haploid cells may undergo internal or external fertilisation and can vary in size, shape, and function from each other. Within the same cell, some organisms contain both sperm and ova.
Complete answer:
Through a process of cell division called meiosis, gametes are formed. Four haploid daughter cells are formed by this two-step division process. Just one group of chromosomes comprises haploid cells. When in a process called fertilisation, the haploid male and female gametes combine, they form what is called a zygote. The zygote comprises two sets of chromosomes and is diploid.
The essence of an organism's sexual reproduction is largely based on the size and shape of its gametes. Some male and female gametes, while others are vastly different, are of similar size and form. Male and female sex cells are almost similar in certain species of algae and fungi, for instance, and both are typically motile. The union of gametes that are identical is known as isogamy.
The process of combining gametes of different size and form is called anisogamy or heterogamy. There is a particular form of anisogamy and oogamy found in higher plants, animals, and certain species of algae and fungi. The female gamete in oogamy is non-motile and much larger than the male gamete, which is fast-moving. This is the form of reproduction in humans that occurs.
The trihybrid genotype is AaBbCc. During fertilisation, it develops 8 forms of gamete.
The following are: ABC, ABc, Abc, Abc, aBC, aBc, abC, abc.
Hence, the correct answer is option (C)
Note: Gametes also exist in plants that reproduce sexually. However since plants alternate between diploid and haploid generations, there are some differences. The flowers use meiosis in flowering plants to generate a haploid generation that produces gametes via mitosis. The female haploid is called the ovule and is generated by the flower's ovary. The haploid ovule produces the female gamete that is ready for fertilisation when ripe.