Chromosomal Abnormalities and Genetic Variation in Human Cells

The video tutorial covers chromosomal abnormalities, starting with karyotypes and moving on to nondisjunction and Down syndrome. It explains the difference between diploid and haploid cells, the role of chromosomes in determining gender, and the implications of chromosomal abnormalities like trisomy 21. The video also discusses mitosis and meiosis, highlighting the processes and potential errors during cell division, such as nondisjunction, which can lead to chromosomal abnormalities. Ethical considerations regarding prenatal testing and potential outcomes are also addressed.

What is the total number of chromosomes in a human body cell?

• 46

• 23

• 92

• 69

What is the term for having an extra copy of chromosome 21?

• Tetrasomy 21

• Trisomy 21

• Nullisomy 21

• Monosomy 21

What procedure can detect chromosomal abnormalities before birth?

• CT Scan

• Amniocentesis

• Ultrasound

• MRI

How many rounds of cell division occur in meiosis?

• One

• Two

• Four

• Three

What process during meiosis contributes to genetic variation?

• Budding

• Crossing over

• Binary fission

• Mitosis

What is the result of abnormal chromosome division?

• Too few or too many chromosomes

• Double the chromosomes

• Correct number of chromosomes

• No chromosomes

During which phase do problems with chromosome separation usually occur?

• Metaphase

• Telophase

• Prophase

• Anaphase

What is nondisjunction?

• Loss of chromatids

• Formation of new chromatids

• Correct separation of chromatids

• Failure of chromatids to separate

Why is nondisjunction more common in older individuals?

• Chromatids become more sticky

• Chromatids become less sticky

• Chromatids decrease in number

• Chromatids increase in number

What is the chance of having a child with no chromosomal problems if nondisjunction occurs in meiosis 2?

• 0%

• 25%

• 75%

• 50%