Meiosis
results of meiosis in females
-a single cell divides forming 1 viable egg and 3 polar bodies -each of the 4 new cells contain 23 chromosomes, half the number of the original parent cell -the polar bodies will be absorbed by the cell
results of meiosis in males
-a single cell divides forming 4 sperm cells -each new cell contains 23 chromosomes, half the number of the original parent cell
gamete egg
also called the egg or ova, the female gamete is made in the ovaries in a process known as oogenesis, the nucleus of the egg contains 23 chromosomes, all ova are produced before the female is born
after meiosis, why is it important for the egg and sperm cell to have only 23 chromosomes and not 46?
because when the sperm and egg join during sexual reproduction each contributes to a new individual so 23 from the sperm and 23 from the egg will equal 46 chromosomes in the new individual
interphase
before meiosis begins, genetic material is replicated during interphase, this DNA replication is similar to interphase during mitosis
telophase 2
cell division is complete, four haploid daughter cells are formed, each cell having 1/2 the genetic information of the parent cell
meiosis
cell division that allows for genetic diversity in sexually reproducing species, results in the production of gametes
anaphase 2
centromeres divide and sister chromatids separate and move to each pole
prophase 1
chromatin condense, each chromosome consists of 2 closely associated sister chromatids, crossing-over can occur
metaphase 2
chromosomes align at the center of the cell
what is meant by DNA replication?
copying
what is the name of the female sex cell?
eggs
eggs
female gametes (sex cells)
each division undergoes how many distinct stages
four distinct stages
metaphase 1
homologous chromosomes align at the center
anaphase 1
homologous pairs separate with sister chromatids remaining together
where are eggs produced
in the ovaries
how many nuclear divisions does meiosis involve
it involves 2 successive divisions
gametes
male and female sex cells
sperm
male gametes (sex cells)
name one way in which meiosis is different from mitosis
meiosis produces 4 daughter cells and mitosis produces only 2 daughter cells.
what is the process called in which the egg and sperm join?
sexual reproduction
what is the name of the male sex cell?
sperm
male gametes
sperm, produced in the male testes during puberty, all sperm contain 23 chromosomes in the process called spermatogenesis, pubescent males will produce sperm throughout their lifetime
where are sperm produced
the male testes
telophase 1
two daughter cells are formed with each daughter cell containing only one chromosome of the homologous pair
fertilization
when an egg and sperm unite during the process of sexual reproduction, a new individual forms, this individual will carry genetic information from both the father and mother
the process of meiosis
when the egg and sperm are formed with each new cell containing 1/2 the number of chromosomes as the original cell
prophase 2
DNA does not replicate
how many chromosomes each are there in the nucleus of the egg and sperm
23 chromosomes
at the end of meiosis, how many daughter cells are present/
4 new sex cells
