At the molecular level - Part 2 Flashcards
1
Q
Phases of the cell cycle
A
- Interphase
2. Miotic phase
2
Q
Stages of mitosis
A
- prophase
- Prometaphase
- Metaphase
- Anaphase
- Telophase
Cytokinesis overlaps with latter stages to comple miotic pase
3
Q
Cytokinesis
A
The division of the cytoplasm where one cell becomes 2
- Division of cytoplasm
- In animal cells: cell pinches in two
4
Q
Interphase: G2
A
- Centrosomes are duplicated
- 2 centrosomes, each with 2 centrioles
- Chromosomes have been duplicated
5
Q
Prophase
A
First stage of mitosis
- Chromosomes condense (two identical sister chromatids joined at centromere
- Nucleoli disappear
- Miotic spindle forms (centrosomes and microtubules)
- Centrosomes pushed away fro each other
6
Q
Prometaphase
A
Stge 2 of mitosis
- Nuclear envelope fragments
- Each of two chromatids now have a kinetochore (a protein structure at the centromere)
- Microtubules attach to kinetochore
7
Q
Metaphase
A
Stage 3 of mitosis
- Centrosomes at oppsote poles of cell
- Chromosomes at metaphase plate
- Plane equidistant between two poles
- Centromeres at metaphase plate
- Kinetochores attached to microtubules from opposite poles
- Miotic spindle
8
Q
Anaphase
A
Stage 4 of mitosis
- Two sister chromatids are pulled apart
- Each chromatid becomes a chromosome
- Daughter chromosomes moved to oppsodite ends of cell have complete copies of chromosomes
9
Q
Telophase
A
Stage 5 of mitosis
- 2 daughter nuclei form
- Nucleoli reappear
- Chromosomes decondense
- Spindle breaks down
- Mitosis is finished
10
Q
Cell cycle: animal vs plants cells
A
- Centrosomes are not necessary for miotic spindle to form
- Plant cells do not have them, but still have miotic spindle
- Animal cells with destroyed centrosomes form miotic spindle too - Cytokinesis
- In animal cells: It occurs by cleavage (microfilaments contract until cell splits in two)
- In plant cells: No cleavage furrow; cell plate produced by vesicles from Golgi during telophase turn into cell walls
11
Q
Cell cycle in bacteria
A
Binary fission
- Type of reproduction prokaryotes undergo
- Cell grows 2x its size, then divides to make 2 cells
12
Q
Steps of binary fission
A
- Replication begins
- One copy of origin of replication moves to opposide end of cell
- The replication continues
- When replication is done, the plasma membrane pinches inward and a new cell wall is made
- Result in two daughter cells
13
Q
Meiosis
A
- How sex cells (gametes) are formed (sperm and eggs)
- Pffspring not identical to either parent and are different of each other
- There are inherited similarities, but also variation
- Variation allows breeding of plants and animals with different characteristics
- Evolution by natural selection works on this variation well
- Duplication of chromosomes followed by 2 consecutive cell divisions
- results in 4 daughter cells
14
Q
Stages of meiosis
A
- Prophase 1
- Metaphase 1
- Anaphase 1
- Telophase 1
- Prophase 2
- Metaphase 2
- Anaphase 2
- Telophase 2
15
Q
Prophase 1
A
- Chromosomes condense
- Homologues pair up and align gene by gene
- Synapsis occurs
- Crossing over
- Synapsis ends
- Each homologous pair has at least 1 chiasmata
- Homologous pairs move toward metaphase
