Question

ALL MULTIPLE CHOICE THREE Questions

Which of the following is true of sexual reproduction?

		The sex chromosomes are called X and Y
		Human females have a homologous pair of X chromosomes (XX)
		Human males have one X and one Y chromosome
		The 22 pairs of chromosomes that do not determine sex are called autosomes
		All of the above are correct

1. Which of the following is true?

		Diploid cells have two chromosomes
		If a diploid cell undergoes meiosis, the resulting cells will be diploid
		When two haploid cells fuse the result is a diploid cell
		All cells in an organism have the same ploidy ****3) Genetic variation occurs when chromosomes are shuffled in _____ and fertilization. mitosis genetic drift meiosis natural selection Mutation

Answer 1

Which of the following is true of sexual reproduction?

Answer: All of the above are correct.

In normal human their 23 pair of chromosomes in each cell, out of which 22 do not determine sex so they are called autosome and one pair is the sex chromosome. In the human male, in sex chromosome, X and Y are present while in female homologous pair of X is present i.e. XX.

Which of the following is true?

Answer: When two haploid cells fuse the result is a diploid cell.

In meiosis type of cell division, there are 4 daughter cells produced and each daughter cells have a half number of chromosomes then the parent cell i.e. if a diploid cell is going under meiosis type of division the daughter cells will have a haploid number of chromosomes. The diploid cells have 2 complete sets of chromosomes i.e. 23+23 as each set has 23 chromosomes. While when haploid cells like gametic cells when they fuse they form a cell which will be diploid. In every organism, different ploidy cells are available for eg. somatic cells have diploid chromosome and gametes have a haploid number of chromosomes.

Genetic variation occurs when chromosomes are shuffled in _____ and fertilization.

Answer: Meiosis.

Genetic variation means the difference in genes or DNA that is present in every one. The fertilization gives genetic variation as the two types of chromosomes are involved which comes from two different individuals and in meiosis, it happens when the crossing over takes place between the homologous chromosomes which takes place between the prophase I of meiosis I.