Chapter 12 Cell Cycle Flashcards
What are the functions of cell division?
- Reproduction
- Growth and Development
- Tissue renewal
What is the cell cycle? Cell division?
The cell cycle is an ordered sequence of events in the life of a cell, from it’s origin in the division of a parent cell until it’s own division into two cells. Cell division is the reproduction of cells.
What is a genome?
All of a cell’s genetic material.
What is the difference between chromosomes and chromatin?
Chromosomes are a cellular structure carrying genetic material. Chromatin are the complex of DNA and proteins that make up Eukaryotic chromosomes.
What is the difference between somatic cells and gametes?
Somatic cells are all the body cells except the reproductive cells. Gametes are the reproductive cells.
What are sister chromatids?
Two copies of a duplicated chromosome attached to each other by proteins at the centromere.
What is a centromere?
Region containing specific DNA sequences where the chromatids are attached.
What is mitosis?
The division of the genetic material of the nucleus.
What is cytokinesis?
The division of the cytoplasm.
What are the two phases of the cell cycle?
- Mitotic phase
2. Interphase
What are the stages of interphase and what happens in each?
G1- acquisition of nutrients and growth to proper size
S- DNA synthesis occurs
G2- completion of growth and readying for division
What are the stages of mitosis and what happens in each?
- Prophase-chromatin could into chromosomes consisting of 2 identical sister chromatids, mitotic spindle forms(asters visible), centrosomes move apart
- Prometaphase-nuclear envelope breaks down, chromosomes are condensed, spindle fibers attach to kinetochores of each chromosome, nonkinetochore microtubules interact with spindle of the opposite pole
- Metaphase-centrosomes now at opposite poles, chromosomes line up along the metaphase plate, kinetochore of each sister chromatid is attached to kinetochore microtubules from opposite poles
- Anaphase-spindle fibers shorten, pulling the sister chromatids apart, chromosomes move toward opposite poles, cell elongates as nonkinetochore microtubules elongate
- Telophase-2 daughter nuclei for in be cell(nuclear envelope reappears), chromosomes become less condensed, spindle fibers break down
- Cytokinesis-Tightening of two sets of protein filaments forms a contractile ring that narrows along the cellular equator, a cleavage furrow develops
What are the end products of mitosis?
Two daughter cells.
What happens during cytokinesis?
Tightening of 2 sets of protein filaments forms a contractile ring that narrows along the cellular equator, as a result of the contractile ring, a cleavage furrow develops, the contractile ring continues to pinch the cell into 2, as this happens the cell membrane fuses creating 2 daughter cells.
How does cytokinesis differ between plants and animals?
In plants, the cell wall prevents formation of cleavage furrow and “pinching off.”