Biology - Silva Flashcards
How many genes are in a chromosome
2,000
What happened at the end of telophase I
Cytokineses
Homologous chromosome condense, they begin to form homologous pairs in a process call?
Synapis
What are the cell division in mitosis and meiosis
One, Two
where does meiosis take place
testes
what is the final stage of meiosis I
Telophase I
What happens during anaphase I
each homologous chromosome is guided by the spindle fibers.
what is the first stage of meiosis I
Prophase I
what is the final stage of meiosis II
Telophase II
What happened at the end of Telophase I
The cells undergoes cytokineses.
The cells go into interphase again
What is a likely result of crossing over during meiosis I?
Production of recombinant gametes
During crossing over, homologous chromosomes trade parts, ultimately resulting in recombinant gametes at the end of meiosis.
How many cell divisions occur during meiosis? A. 2 B. 1 C. 3 D. 0
2
Meiosis consists of two cell divisions. The first occurs during meiosis I and the other occurs during meiosis II.
Which of the following statements are true about meiosis II?
A. It results in the formation of four haploid (n) gametes.
B. It results in the formation of two haploid (n) cells.
C. Its goal is to separate sister chromatids.
D. Its goal is to separate homologous pairs of chromosomes.
A. It results in the formation of four haploid (n) gametes.
C. Its goal is to separate sister chromatids.
Dr. Evil just discovered a way to prevent crossing over from occurring during meiosis in the gametes of her lab rats.
Which of the following answer choices best describes the effects her discovery would have on the lab rats?
A. Prophase I would be disrupted and there would increased genetic variation in the rats’ offspring.
B. Prophase II would be disrupted and there would reduced genetic variation in the rats’ offspring.
C. Prophase I would be disrupted and there would be reduced genetic variation in the rats’ offspring.
D. Prophase I would be disrupted, but prophase II would occur normally, resulting in increased genetic variation in the rats’ offspring.
A. Prophase I would be disrupted and there would be reduced genetic variation in the rats’ offspring.
Crossing over occurs during prophase I of meiosis I and results in genetic recombination, which promotes genetic variation. If this is prevented, genetic variation would be significantly reduced in the offspring.
Which of the following statements are true about meiosis II?
A. It results in the formation of four haploid (n) gametes.
B. Its goal is to separate sister chromatids.
C. Its goal is to separate homologous pairs of chromosomes.
D. It results in the formation of two haploid (n) cells.
A. It results in the formation of four haploid (n) gametes.
B. Its goal is to separate sister chromatids.
If a cat cell undergoes meiosis, how many chromosomes will be in the resulting cell? A. 13 B. 76 C. 19 D. 38
C. 19
During meiosis, when does the ploidy (number of sets of chromosomes) get reduced from diploid (2n) to haploid (n)?
A.Once telophase I of meiosis I is complete
B.Once prophase I of meiosis I is complete
C.Once telophase II of meiosis II is complete
D.Once anaphase I of meiosis I is complete
A. Once telophase I of meiosis I is complete
After this stage is complete, the homologous pairs of chromosomes are completely separate from one another in two separate cells, thereby reducing the ploidy from diploid (2n) to haploid (n).
What event is labeled as Process Z in the diagram?
Diagram showing interphase and meiosis, broken into three labeled processes: X, Y, and Z
A
Meiosis I
B
Meiosis II
C
Interphase
D
Mitosis
Meiosis II
During process Z, sister chromatids are separating to form four haploid gametes. This occurs during meiosis II.
What is the overall purpose of meiosis?
To create gametes
Gamete (sex cell) formation is the major role of meiosis.
Which of the following answer choices best describes the effects her discovery would have on the lab rats?
Prophase I would be disrupted and there would be reduced genetic variation in the rats’ offspring.
Crossing over occurs during prophase I of meiosis I and results in genetic recombination, which promotes genetic variation. If this is prevented, genetic variation would be significantly reduced in the offspring.
Humans normally have 46 chromosomes spread out over 23 pairs. Down syndrome, also known as trisomy 21, occurs when there’s an extra chromosome at the chromosome 21 pair (shown above).
Sister chromatids fail to separate at chromosome 21 during anaphase II in a parent’s gamete.
This failure to separate results in the formation of a gamete that has two chromosomes at spot 21 when they should only have one. When this gamete fuses with the other parent’s gamete, a total of three chromosomes are at spot 21 in the offspring.
Which of the following is true of meiosis?
It produces haploid cells.
Meiosis results in the formation of gametes, haploid cells containing half of the genetic information of a somatic cell
