This document contains a biology review with 10 questions covering topics of cell division, chromosomes, and mutations. The questions assess understanding of key concepts like independent assortment, fertilization, meiosis, karyotypes, chromosomal abnormalities, and genetic variation. Correct answers are not provided, rather the student is expected to show their work and explain their reasoning for questions involving calculations and comparisons of DNA content during cell cycle stages. The review covers foundational material relevant to inheritance, genetics, and prenatal testing.

1. Mr. Hunter
Biology Review
11/24/2009
Cell division, Chromosomes
and mutations
Name _______________________ Date ________ Period ________
1. Based on the concept of independent assortment, what are the possible
chromosome combinations for a human diploid cell? What is the formula for this
calculation? _________
2. When the gamete of one individual unites with a gamete of another individual of
the opposite sex, fertilization occurs. What is the number of possible
combinations of chromosomes that can be produced by fertilization?
______________ ( show your calculations )
3. If an intestinal cell of a grasshopper contains 24 chromosomes, a grasshopper
sperm cell would contain how many chromosomes? ___________ why?
4. A fruit fly somatic cell contains 8 chromosomes. This means that _________
different combinations of chromosomes are possible in its gametes. (show
calculations )
5. What are the major differences between mitosis and meiosis?
6. You are a doctor at St. Joseph Hospital in Detroit. Your patient is a 39 year old
female who is pregnant. You advise her that she should have prenatal testing
(Amniocentesis : small amount of amniotic fluid that surrounds the fetus is
removed. This fluid contains fetal cells.) She reluctantly agrees. The karyotype
shows an extra copy of chromosome 21. What do you tell your patient about her
unborn child? Why did you think this abnormality occurred?
7. Breakage of a chromosome can lead to _______ number of mutations. Describe
each mutation. Include a sketch of each type. (pg. 124 Holt Biology as a guide )
8. The DNA content of a diploid cell in the G1 phase of the cell cycle is measured. If
this DNA content is represented as 10X, then the DNA content of the same cell at
metaphase of meiosis I would be ___________. Explain your answer.
9. What would the DNA content of the same cell be at meiosis II (metaphase)?
________ Explain your answer.
10. How does crossing over and independent assortment contribute to genetic
variations among offspring?