Lecture 19: Chromosomes, the Cell Cycle, and Mitosis Flashcards
1
Q
How does bacteria store genetic information? (Prokaryotic)
A
- Circular, single copy, naked ds DNA
2
Q
How do protists, fungi, plants, and animals store genetic information? (Eukaryotic)
A
- Linear, more than a single copy, histone-bound DNA, usually sexual reproduction
3
Q
Each human cell contains about _____ metres of DNA
A
- 3
4
Q
There are ___ human chromosomes
A
- 22
5
Q
Multicellular organisms depend on cell division for:
A
- Development from a fertilised cell
- Growth to adults
- Repair
6
Q
Phases of the Cell Cycle:
A
- Interphase (G1, S, G2)
- Mitotic Phase (Mitosis, Cytokinesis)
7
Q
Mitosis consists of five phases….
A
- Prophase
- Prometaphase (asters at each end of cell, nuclear envelope disintegrates, kinetochore microtubules attach to chromosomes)
- Metaphase
- Anaphase
- Telophase
8
Q
What happens during anaphase?
A
- Kinetochore microtubules shorten, and chromatids are separated, non kinetochore microtubules get longer
9
Q
What happens during telophase?
A
- Two cells starting to form, nucleolus forming
10
Q
What happens during cytokinesis?
A
- Cytoplasm divides into two
11
Q
What occurs exactly during the cell cycle?
A
- DNA replication
- DNA condenses
- Chromatin condenses further
- Sister chromatids
- Interphase:
- G1 (gap 1 phase) : Everything is replicated
- Synthesis phase: DNA replication
- G2: Everything that needs to be produced is produced
- Mitosis: Prophase, Metaphase, Anaphase, Telophase
- Prophase: Centrioles, spindles start growing, migrate to opposite poles, spindle apparatus, nuclear envelope breaks down, kinetochores attach to
- Metaphase: aligned at equator
- Anaphase: free individual chromosomes, pulled to opposite sides
- Telophase: Two cells start to form
- Cytokinesis: Cleavage (animal), Vesicles form in cell plate (plants)
12
Q
Checkpoints occur during the cell cycle phase…
A
- G1/S
- G2/M
- Spindle
13
Q
How long does cell replication take in a typical human / animal cell?
A
- 10 / 20 hours
