THE CELLULAR BASIS OF INHERITANCE
somatic cells
all the cells of a multicellular organism except the gametes or reproductive cells
Polyploidy
condition in which an organism has extra sets of chromosomes
Which of these leads to the movement of genes on one chromosome to a homologous chromosome during Meiosis?
crossing over
Meiosis produces ________ daughter cells.
four haploid
Describe the SRY gene and how crossing over may result in males with XX karyotypes or females with XY
provides instructions for making a protein called the sex-determining region Y protein. This protein is involved in male sexual development, which is usually determined by the chromosomes an individual has
If a muscle cell of a typical organism has 32 chromosomes, how many chromosomes will be in a gamete of that same organism?
16
Describe the purpose of meiosis in sexual reproduction
During sexual reproduction, meiosis generates genetic variation in offspring because the process randomly shuffles genes across chromosomes and then randomly separates half of those chromosomes into each gamete. The two gametes then randomly fuse to form a new organism.
Explain how the processes of meiosis and fertilization lead to genetic variation in populations.
Genetic variation is increased by meiosis. During fertilisation, 1 gamete from each parent combines to form a zygote. Because of recombination and independent assortment in meiosis, each gamete contains a different set of DNA. This produces a unique combination of genes in the resulting zygote Fertilization creates genetic diversity by allowing each parent to randomly contribute a unique set of genes to a zygote. While fertilization is not part of meiosis, it depends on meiosis creating haploid gametes. The fertilized cell restores the diploid number
Fertilization
Process in sexual reproduction in which male and female reproductive cells join to form a new cell
The part of meiosis that is similar to mitosis is ________.
meiosis II
What term describe a gamete that has one extra chromosome #21?
Aneuploidy
Explain how aneuploidy occurs in gametes and describe characteristics of chromosomes that might increase chance of survival in some cases of aneuploidy.
Aneuploidy is the presence of an abnormal number of chromosomes in a cell. It originates during cell division when the chromosomes do not separate properly between the two cells.
Explain the processes of crossing over and independent assortment in meiosis.
Crossing Over: (also, recombination) the exchange of genetic material between homologous chromosomes resulting in chromosomes that incorporate genes from both parents of the organism forming reproductive cells Independent Assortment: formation of random combinations of chromosomes in meiosis and of genes on different pairs of homologous chromosomes by the passage according to the laws of probability of one of each diploid pair of homologous chromosomes into each gamete independently of each other pair.
germ cells
a specialized cell that produces gametes, such as eggs or sperm
Distinguish between mitosis and meiosis in the types of cells that are produced and the proportion of chromosomes after cell division.
in Meiosis, one cell divided twice to form four daughter cells. These four daughter cells only have half the number of chromosomes of the parent cell - they are haploid. Meiosis produces our sex cells or gametes (eggs in females and sperm in males) The purpose of mitosis is to produce two daughter cells identical to the original cell. If a diploid (2n) cell undergoes mitosis successfully, the two daughter cells should also be diploid (2n). If a haploid (n) cell undergoes mitosis successfully, the two daughter cells should be haploid (n).
Aneuploidy
the presence of an abnormal number of chromosomes in a cell
