7.5 SG Flashcards
What is nondisjunction?
Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate properly during cell division.
True or False: Nondisjunction can occur during both meiosis I and meiosis II.
True
Fill in the blank: Nondisjunction can lead to __________ in the resulting gametes.
aneuploidy
What are the sex chromosomes in humans?
The sex chromosomes in humans are X and Y.
What condition is caused by the presence of an extra X chromosome in males?
Klinefelter syndrome
During which phase of meiosis does homologous recombination occur?
Prophase I
Multiple Choice: What is the primary result of nondisjunction during meiosis? A) Increased genetic diversity B) Aneuploidy C) Cell death
B) Aneuploidy
What is the term for an individual with only one X chromosome?
Turner syndrome
True or False: Meiosis produces four genetically identical daughter cells.
False
What are the two main stages of meiosis?
Meiosis I and Meiosis II
Fill in the blank: The process of __________ is essential for the reduction of chromosome number in meiosis.
meiosis
Short Answer: What happens during anaphase I of meiosis?
Homologous chromosomes are pulled apart to opposite poles.
Multiple Choice: Which of the following is a result of nondisjunction? A) Down syndrome B) Hemophilia C) Sickle cell anemia
A) Down syndrome
In which phase of meiosis do sister chromatids separate?
Anaphase II
True or False: Nondisjunction occurs more frequently in older mothers.
True
What is the difference between aneuploidy and polyploidy?
Aneuploidy is the presence of an abnormal number of chromosomes, while polyploidy is the presence of more than two complete sets of chromosomes.
Fill in the blank: The __________ phase of meiosis is where the chromosomes condense and the nuclear envelope breaks down.
prophase I
Short Answer: What is the significance of crossing over during meiosis?
It increases genetic variation by exchanging genetic material between homologous chromosomes.
What is the outcome of nondisjunction in gametes during fertilization?
It can result in zygotes with an abnormal number of chromosomes.
Multiple Choice: What is the primary function of meiosis? A) Growth B) Repair C) Production of gametes
C) Production of gametes
True or False: All forms of aneuploidy are viable.
False
What is the term for the process of cell division that reduces the chromosome number by half?
Meiosis
Fill in the blank: In humans, the presence of an extra chromosome 21 results in __________.
Down syndrome
Short Answer: Describe what happens during telophase I of meiosis.
The cell divides into two haploid cells, and the nuclear envelope may reform.
Multiple Choice: Which phase of meiosis is characterized by the alignment of homologous chromosomes at the equatorial plate? A) Metaphase I B) Anaphase II C) Telophase I
A) Metaphase I
