Download Chapter 8 – Study Guide What is the role of histones in the cell

Chapter 8 – Study Guide
1. What is the role of histones in the cell?
Proteins that DNA wraps around in order to allow the genetic code to fit into the
nucleus.
2. Explain the difference between chromatids and chromosomes.
Chromatids are two identical halves of a chromosome.
3. What is the difference between prokaryotes and eukaryotes chromosomes?
Prokaryotic DNA is circular. They only have 1 chromosome and no nucleus.
Eukaryotic DNA is linear and have many chromosomes.
4. What is binary fission?
Cell reproduction in bacteria.
5. What are the stages of the cell cycle in order?
G1  S  G2  M  C
6. What occurs during crossing over in prophase I?
Genetic material is swapped between tetrads of chromosomes. This increases
the variability within offspring.
7. What is a tetrad?
Homologus chromosomes that are next to each other and part during anaphase
I.
8. What are the end products of the cell cycle? Meiosis?
4 non-idential haploid cells.
9. What is the advantage of sexual reproduction over asexual reproduction?
Sexual reproduction increases the advances of evolution as well as the variation
among offspring.
10. What happens during the three stages of interphase?
The cell first grows, doubles the organelles, duplicates the DNA, and grows some
more. Throughout this time the cell is being regulated with cyclins.
11. What do cyclins do?
Keep time of cell cycle as well as check/repair for any signs of mutation or
change.
12. Why are stem cells important?
They have the ability to become any type of cell in the body.
13. What is the importance of chromosomes during cell division?
During mitosis, the nucleus of a cell divides into two nuclei, each containing a
complete set of the cell’s chromosomes. Thus, each new cell formed during cell
division contains identical DNA.
14. What do cancer cells look like? What can they develop into?
Cancer cells typically do not have a circular round shape like normal cells. They
have much less cytoplasm, and their nuclei are dark and dense. If cancer cells
are not stopped and regulated, they can become a tumor.
15. Fill in the follow tables.
Stage of cell
cycle
What’s happening?
Cell growth
Interphase
Duplication of organelles
Duplication of DNA
Regulation
Chromatin  Chromosomes
Prophase
Nucleus disappears
Centrioles begin to make sprindle
fibers and move to opposite poles
Metaphase
Chromsomes line up at the
equator of the cell
Anaphase
Chromosomes split at the
centromere and break into sister
chromatids
Plant: Nuclei reappear,
Chromosomes  Chromatin, cell
plate forms in center of two cells
Telophase
Cytokinesis
Animal: Nuclei reappear,
Chromosomes Chromatin,
cleavage furrow forms in center of
two cells
Cytoplasm splits into two separate
cells
What cell looks like
Stage of Meiosis
Prophase I
What’s happening?
Nucleus disappears
Chromatin  Chromosomes
Spindle fibers from centrioles
Centrioles move to opposite poles
Tetrads form, crossing over
Metaphase I
Tetrads line up randomly along
equator of the cell
Anaphase I
Tetrads separate randomly to
opposite poles of the cell
Telophase/
Chromosomes reach opposite
poles
Cytokinesis I
Cleavage furrow appears
Nucleus disappears
Prophase II
Chromosomes move
Spindle fibers from centrioles
Metaphase II
Chromosomes line up randomly
along equator of the cell
Anaphase II
Chromosomes separate randomly
to opposite poles of the cell
Telophase/
Chromosomes reach opposite
poles
Cytokinesis II
Cleavage furrow appears
What cell looks like