Gametes (sex cells)?

Question

Gametes undergo meiosis rather than mitosis...why?

Answer 1

Remember -- gametes are haploid cells so they contain one complete set of chromosomes. Two gametes (usually one sperm from the male and one egg from the female) fuse to form a zygote, which has two complete sets of chromosomes (diploid).

So, a zygote is a diploid cell. It differentiates into the cells that make up the human body. The somatic cells (those cells not involved in reproduction -- basically every cell type apart from the sperm and the egg) have two sets of chromosomes and must therefore undergo mitosis, which involves one division of a diploid cell into two daughter diploid cells. The gametes (sex cells) are haploid, and therefore must undergo TWO divisions from the parent diploid cell to have one set of chromosomes each. The two-division process is meiosis.

Just for reference, in males the gametes are formed by meiosis from parent diploid cells in the gonads after puberty, while in female the gametes are formed by meiosis before or right after birth.

Answer 2

gametes need to go through meiosis because it is haploid. remember: gametes are formed through first separating the individual's mom's and dad's genes and second...replicating. so in a way, the gametes partly go through meiosis since meiosis 2 is basically like mitosis.

also, as one of the answerers said, during meiosis1, variation in genes occur. the mom and dad genes are mixed up. this way, there are a million types of unique kids a couple can have.

mitosis on the other hand, won't be able to make a haploid since all it does is replication of the genes and separating the same exact genes...the daughter cells will still be diploid!

haploid is needed so that when a sperm (a haploid) and an egg(another haploid) come together......then they make a diploid and that diploid goes through many mitosis and soon growns into a child! the miracle of life!

Answer 3

Meiosis is the only process that allows variety of gametes to be produced. If mitosis occurs in gametes, whether in female or male gametes, then a baby will have the same look with another baby. Meiosis assures that variation happens, that's all........as simple as that

Answer 4

A gamete is a specialized germ cell that fuses with another gamete during fertilization (conception) in organisms that reproduce sexually. In species which produce two morphologically distinct types of gametes, and in which each individual produces only one type, a female is any individual which produces the larger type of gamete—called an ovum (or egg)—and a male produces the smaller type—called a spermatozoon (or sperm cell).

The creation of gametes is gametogenesis, and during it gametocytes divide by meiosis into gametes. Organs that produce gametes are called gonads in animals, and archegonia or antheridia in plants. The term gamete comes from the ancient Greek γαμετης (spouse).

Gametes are haploid cells; that is, they contain one complete set of chromosomes (the actual number varies from species to species). When two gametes fuse (in animals typically involving a sperm and an egg), they form a zygote—a cell that has two complete sets of chromosomes and therefore is diploid. The zygote receives one set of chromosomes from each of the two gametes through the fusion of the two gamete nuclei. After multiple cell divisions and cellular differentiation, a zygote develops, first into an embryo, and ultimately into a mature individual capable of producing gametes. Gametes from a mature diploid individual are produced in the gonadal tissue through meiosis —a process of cellular division that reduces the number of sets of chromosomes from two to one (i.e., produces haploid gametes).

The diploid somatic cells of an individual contains one copy of the chromosome set from the sperm and one copy of the chromosome set from the egg; that is, the cells of the offspring have genes expressing characteristics of both the father and the mother. A gamete's chromosomes are not exact duplicates of either of the sets of chromosomes carried in the somatic cells of the individual that produced the gametes. They can be hybrids produced through crossover (a form of genetic recombination) of chromosomes, which takes place in meiosis. This hybridization has a random element, and the chromosomes tend to be a little different in every gamete that an individual produces. This recombination and the fact that the two chromosome sets ultimately come from either a grandmother or a grandfather on each parental side account for the genetic dissimilarity of sibling's.

Isogamy is the state of gametes from both sexes being the same size. Anisogamy or heterogamy is the condition wherein females and males produce gametes of different sizes.

Answer 5

Sexual reproduction occurs only in eukaryotes. During the formation of gametes, the number of chromosomes is reduced by half, and returned to the full amount when the two gametes fuse during fertilization.

Answer 6

because mitosis is simple cellular division in where the cell comes up with a daughter cell directly similar to the parent cell. the sex cells are more specialized in biological evolution and are more complex. they take 23 cells from each of the parents and combine them. thus making meiosis more complex and allowing room for evolution. also leaving room for variations and leaving the daughter cell, or offspring, different from the parent cell.