Meiosis is the type of nuclear division that occurs in the sex organs during gam
ID: 89587 • Letter: M
Question
Meiosis is the type of nuclear division that occurs in the sex organs during gamete (egg and sperm) formation. As shown on pages 68-69, meiosis results in four daughter cells because there are two rounds of nuclear division. It also reduces the chromosome number to half that of the parent cell. The parent cell is said to be diploid (2n) because it contains homologues (homologous chromosomes) that lookalike and carry genetic material for the same traits, such as fingers, hairline, or earlobes. Each gamete is haploid (n) because it contains only one from each pair of homologues. Fill in the blanks below. 1. Meiosis reduces the chromosome number. If the parent cell is 2n = 4, the daughter cells are n = ________. Without meiosis the chromosome number would double with each generation. Instead, when a haploid sperm fertilizes a haploid egg, the new individual is 2n. 2. Sexual reproduction results in offspring that can look very different. Why do the offspring born to the parents show variation? a. During prophase I, the homologues come together and exchange genetic material. Now the inherited chromosomes will be different from those in the parent cell. This process is called ______ b. During anaphase I, the homologues separate differently and therefore the daughter cells following telophase I can have different _______ of chromosomes. c. During fertilization variant sperm fertilize variant eggs, further helping to ensure that the new individual inherits different ______ of homologues than a parent had.Explanation / Answer
Answer:
1) Meiosis reduces the chromosome number. If the parent cell is 2n = 4, the daughter cells are n = 2 cells. Without meiosis the chromosome number would double with each generation. Instead, when a haploid sperm fertilizes a haploid egg, the new individual is 2n.
2) Sexual reproduction results in offspring that can look very different. Why do the offsprings born to the parents show variation?
3) During prophase I, the homologous come together and exchange genetic material. Now the inherited chromosomes will be different from those in the parent cell. This process is called Synapsis.
4) During anaphase I, the homologous separate differently and therefore the daughter cells following telophase I can have different combinations of chromosomes.
5) During fertilization variant sperm fertilizes variant eggs, further helping to ensure that the new individual inherits different features of homologues than a parent had.