Nondisjunction and Chromosomal Abnormalities

The video tutorial explains the differences between mitosis and meiosis, highlighting that mitosis is an asexual process occurring in somatic cells, while meiosis is a sexual process occurring in gametes. It covers the structure of chromosomes, the process of karyotyping, and the implications of chromosomal abnormalities such as Down syndrome. The tutorial also discusses nondisjunction and its role in chromosomal errors, which can lead to conditions like trisomy and miscarriages.

What is the primary difference between mitosis and meiosis?

• Mitosis results in identical cells, while meiosis results in genetically diverse cells.

• Mitosis occurs in gametes, while meiosis occurs in somatic cells.

• Mitosis involves two parent cells, while meiosis involves one.

• Mitosis reduces chromosome number, while meiosis maintains it.

Which type of cells undergo mitosis?

• Somatic cells

• Zygotes

• Stem cells

• Gametes

What is the role of the centromere in a chromosome?

• It is responsible for genetic recombination.

• It determines the length of the chromosome.

• It initiates cell division.

• It holds sister chromatids together.

How many autosomes are present in a human karyotype?

• 24

• 22

• 23

• 21

What condition is characterized by having three copies of chromosome 21?

• Patau syndrome

• Turner syndrome

• Down syndrome

• Klinefelter syndrome

What is nondisjunction?

• The deletion of a chromosome segment

• The fusion of two chromosomes

• The failure of chromosomes to replicate

• The failure of chromosomes to separate properly

Which phase of meiosis is most associated with nondisjunction?

• Prophase

• Telophase

• Metaphase

• Anaphase

What is the result of a spindle fiber error during cell division?

• Chromosomal abnormalities

• Increased cell size

• Normal cell division

• Decreased cell size

What is the term for having three copies of a chromosome?

• Monosomy

• Tetrasomy

• Disomy

• Trisomy

Which factor increases the likelihood of nondisjunction?

• Regular exercise

• Balanced diet

• Old parental age

• Young parental age