All Flashcards
What is the effect of crossing over during prophase I?
Increases genetic diversity by creating new combinations of alleles on the same chromosome.
What is the effect of independent assortment during metaphase I and II?
Increases genetic diversity by creating different combinations of maternal and paternal chromosomes in gametes.
What is the effect of random fertilization?
Increases genetic diversity by allowing any sperm to fertilize any egg, creating a unique combination of genes.
What is the effect of nondisjunction during meiosis?
Results in gametes with an abnormal number of chromosomes, potentially leading to genetic disorders such as Down syndrome.
What are the key differences between Meiosis I and Meiosis II?
Meiosis I: Homologous chromosomes separate | Meiosis II: Sister chromatids separate
What are the key differences between Trisomy and Monosomy?
Trisomy: Presence of an extra chromosome (2n+1) | Monosomy: Absence of one chromosome (2n-1)
What are the key steps of Crossing Over?
- Homologous chromosomes pair up. 2. Exchange of genetic material occurs during prophase I. 3. New combinations of alleles are created on the same chromosome.
What are the key steps of Independent Assortment?
- Homologous chromosome pairs align randomly at the metaphase plate during metaphase I and II. 2. Maternal and paternal chromosomes are distributed randomly into daughter cells. 3. Different combinations of chromosomes result in the gametes.
What are the steps that lead to Down Syndrome?
- Nondisjunction occurs during meiosis, resulting in an egg or sperm with an extra copy of chromosome 21. 2. The gamete with the extra chromosome 21 fertilizes a normal gamete. 3. The resulting zygote has three copies of chromosome 21 (trisomy 21), leading to Down syndrome.