Chapter 9 Patterns of Inheritance

What is the primary purpose of meiosis?

To reduce the chromosome number by half and generate genetic diversity in gametes

During which phase of meiosis does crossing over occur?

Prophase I

What is the significance of the independent assortment of homologous chromosomes during metaphase I?

It increases genetic variation among gametes by randomizing chromosome combinations

During which phase are sister chromatids finally separated in meiosis?

Anaphase II

What is the process called when homologous non-sister chromatids exchange DNA segments?

Crossing over

What is the main consequence of nondisjunction?

Abnormal chromosome number in gametes, leading to conditions like Down syndrome

How does crossing over during prophase I contribute to genetic variation?

By exchanging DNA segments between homologous chromosomes, creating new allele combinations

Which syndrome is caused by the presence of an extra X chromosome (XXY), and what are its effects?

Klinefelter syndrome; causes sterility and some feminine characteristics in males

Which of the following is NOT a characteristic of cancer cells?

They respond normally to cell cycle control signals

Which statement best explains how meiosis increases genetic diversity?

Through crossing over, independent assortment, and random fertilization, meiosis creates genetically unique gametes and offspring