Cell Reproduction Flashcards
1
Q
Cell division in prokaryotes
A
- Binary fission; clonal reproduction
2
Q
Chromosomes
A
- made of chromatin – complex of DNA and histone proteins
- a single chromosome is one ling continuous double-stranded fiber
3
Q
Nucleosome
A
- complex of DNA and histone proteins (1 linker+8 core)
4
Q
Eukaryotic cell cycle
A
- Interphase - G1, S, G2
- Mitosis
- Cytokinesis
5
Q
Interphase
A
G1 - cell acquires nutrients required for cell replication
S - replication of DNA
G2 - organelle replication
6
Q
Important terms from S phase
A
- centromere - a constriction on a chromosome
- sister chromatid - replicated copies of a chromosome
- cohesin protein - holds sister chromatids together
7
Q
Phases of mitosis
A
- Prophase - nuclear envelope breaks down
- Prometaphase - microtubules start attaching to kinetochores
- Metaphase - metaphase plate is formed
- Anaphase - cohesin breaks down, microtubules pull sister chromatids toward opposite ends
- Telophase - microtubules break down
- Cytokinesis - cleavage furrow forms and two cells are formed
8
Q
Cell cycle control
A
- G1/S - cell decides to divide
- G2/M - ensure accurate DNA replication
- late metaphase - ensure all chromosomes are properly attached to the spindle
9
Q
CDK (cyclin dependent kinases)
A
- cyclin binds to CDK
- kinase phosphorylates cyclin and CDK complex
- activated complex phosphorylates target protein
- target protein regulates cell cycle
10
Q
Cancer-related genes
A
- tumor suppressor genes
- proto-oncogenes
11
Q
Tumor suppressor genes (p53)
A
Monitors DNA integrity during cell replication. These genes are absent in cancer ells
1. if DNA is damaged, cell division is halted and repair enzymes are stimulated
2. if DNA is irreparable, p53 directs the cell to apoptosis
12
Q
Proto-oncogenes
A
Cancer development is caused when these genes are mutated
