REVIEW SHEET
Chromosomes, Mitosis & Meiosis
Name ________________________
1. What is the purpose of DNA in the cell?
Stores genetic info
3. What is the structure of a chromosome in a eukaryotic cell?
Rod-shaped
In a prokaryotic cell?
Circular, single chromosome
4. What are histone proteins?
DNA wraps around h.p. – they help to maintain chromosome shape
5. Where are chromosomes found in a eukaryotic cell?
Inside the nucleus
6. What is a chromatid?
Identical strands of DNA that make up a chromosome
7. What is a centromere?
Holds the chromatids together
8. What is an autosome?
All chromosomes except the sex chromosomes
How many autosomes does each of your cells have?
44
9. What is a sex chromosome, and why is it different from an autosome?
They determine the gender of an organism
How many sex chromosomes does each of your cells have?
2
10. What is the karyotype notation for a normal male?
46xy
11. What is the karyotype notation for a normal female?
46xx
12. What is a karyotype? How is it prepared and why is it useful?
Pictures of the chromosomes arranged by size, paired up.
Doctors will look for extra or missing chromosomes.
13. What is a HOMOLOGOUS pair of chromosomes? 2 of the same chromosome,
one is from the mother, one is from the father.
14. How many homologous pairs do you have in each of your somatic cells? 23
What is a somatic cell? All cells except your sex cells.
15. What does DIPLOID mean? How is it abbreviated? What type of cell
is diploid?
Cells having 2 copies of each chromosome. 2n. Somatic Cells.
16. What does HAPLOID mean? How is it abbreviated? What type of cell
is haploid?
Cells having only 1 copy of each chromosome. 1n. sex cells
17. Describe binary fission? What type of organism uses binary fission?
Prokaryotes – one cell divides into 2 identical cells – asexual.
18. In terms of structure, what is the major difference between a
prokaryote and a eukaryote?
Prokaryotes do NOT have a nucleus – Eukaryotes DO.
19. Mitosis occurs in what type of cells (somatic or sex cells)?
20. Meiosis occurs in what type of cells (somatic or sex cells)?
21. When does INTERPHASE occur in the cell? Between cell divisions
Name the three phases of interphase and briefly describe each:
1. G1 – cell grows to mature size
2. S phase - DNA is copied
3. G2 – cell prepares to divide
22. What does MITOSIS divide? The nucleus
23. What does CYTOKINESIS divide? The cytoplasm
24. What is CHROMATIN? Uncoiled DNA
25. What is the purpose of the SPINDLE in mitosis?
Moves chromosomes wherever they need to go
STUDY THE MITOSIS & MEIOSIS DIAGRAMS IN
YOUR FOLDER!
26.
27. What type of cell forms a cleavage furrow (plant or animal cell)?
28. What type of cell forms a cell plate (plant or animal cell)?
29. In what stage of cell division do the organelles from the original cell
divide between the two newly formed cells?
Cytokinesis
30. Compare the resulting cells of mitosis to the resulting cells of meiosis
 Cells after mitosis – haploid or diploid (circle one)
 Cells after meiosis - haploid or diploid (circle one)
31. What is a gamete? Sex cells (egg or sperm)
32. Does interphase occur before meiosis I begins? YES
32. Does interphase occur between meiosis I and meiosis II? NO
33. What is the ploidy of a cell (haploid or diploid) when it begins meiosis I?
34. How many cells are formed during meiosis I? 2
35. What is the ploidy of a cell when it begins meiosis II (haploid or diploid)?
36. How many cells are formed during meiosis II? 4
37. What is the ploidy of a cell after it completes meiosis II (haploid or diploid)?
38. In the circles below, draw a cell as it would look in that particular stage,
if the 2n chromosome number would be 4. Then, circle whether the cell
is haploid or diploid in that particular stage.
Diploid cell = 4 chromosomes
Metaphase
During Mitosis
Metaphase I
Metaphase II
haploid / diploid
haploid / diploid
haploid / diploid
39. What is SYNAPSIS and when does it occur?
Pairing of homologous chromosomes during Prophase I
40. What is CROSSING-OVER and when does it occur?
Homologous chromosomes wrap around each other and portions will break
off and reattach to the opposite chromosome.
41. What is INDEPENDENT ASSORTMENT and when does it occur?
Anaphase I – homologous pairs are separated and go to opposite poles
42. In which part of the human body does meiosis take place?
Sex organs (ovaries or testes)
43. What is SPERMATOGENESIS?
Process of sperm formation
44. What is OOGENESIS?
Process of egg formation
How many cells total are formed during oogenesis? 4
How many of these cells are EGG cells? 1
What are the other cells called? Polar bodies
What is the function of these “other” cells? None.
45. Compare sexual and asexual reproduction:
o
o
46.
How many parents are required for each? (one or two)
 Sexual: 2
 Asexual: 1
How do the offspring compare to the parents? (different or
identical?)
 Sexual: different
 Asexual: identical
STUDY THE MEIOSIS DIAGRAMS IN YOUR
NOTEBOOK. Also study the “cut & paste” meiosis
diagram that you made in class.