Chapter 8 Flashcards
What is the cell theory? Hint: where do cells come from?
Cells come from other cells.
Prokaryotic cells reproduce by B_ _ _ _ y F _ _ _ _ _ _n.
Binary fission.
True or false: a prokaryotic cell only has one circular DNA.
True.
What is replication?
Making copies of DNA.
True or false: there is only 1 chromosome in eukaryotic cells.
False, there can be more than 1.
True or false: eukaryotic cells chromosomes are straight linear.
True.
Do different species have different numbers of chromosomes in their cells, or do all species have the same number?
Different species have different numbers.
True or false: chromosomes and chromatins are NOT both DNA and protein combinations.
False, they both are.
Where is eukaryotic genetic material stored?
The nucleus.
True or false: before a cell divides, it duplicates all of its chromosomes, resulting in two copies called sister chromatids.
True.
True or false: two sister chromatids attach to each other at centromere.
True.
The sister chromatids are so sisterly that they never separate from each other, even during cell division.
False, they do separate during cell division.
Human somatic cells have _ _ chromosomes?
46.
True or false: eukaryotic cell cycle includes interphase and mitotic phase.
Interphase includes G1, S phase and G2, it is during S phase when DNA replication occurs.
Both are true.
What is the division of the nucleus called? M _ _ _ _ _ s.
Mitosis is the division of the nucleus.
What is the division of cytoplasm called? C _ _ _ _ _ _ _ _ _ s.
Cytokinesis is the division of cytoplasm.
True or false: animals and plants go through cytokinesis exactly the same way.
False.
What are the 4 basic phases of mitosis?
1) P _ _ _ _ _ _ e
2) M _ _ _ _ _ _ _ e
3) A _ _ _ _ _ _ e
4) T _ _ _ _ _ _ _ e
1) Prophase
2) Metaphase
3) Anaphase
4) telophase
What happens during prophase?
- chromosomes first become visible
- nuclear envelope disintegrates
- centrosomes (centrioles in animals) make protein cables/a spindle.
- cables in a spindle are made of microtubules.
- microtubules attach to chromosomes
- Process is complete when the sister chromatids of a duplicated chromosome are attached by 2 microtubules to opposite poles of the cell.
Chromosomes first become visible with a microscope because the nuclear envelope begins to disintegrate. Centrosomes (centrioles in animal cells) begin to assemble a network of protein cables called the spindle. Cables in the spindle are made of microtubules. Microtubules attach to chromosomes. Process is complete when the sister chromatids are attached by 2 microtubules to opposite poles of the cell.
What happens during prophase? (simplified version).
Microtubules attach to sister chromatids and bring them to opposite poles of the cell.
Why are spindles important? Hint: think of their function. They pull the sister chromatids to opposite poles of the cell.
They are responsible for ensuring that cell division is correct.
What happens during metaphase? Hint: the sister chromatids leave the poles and go back to the c _ _ _ _ r.
The sister chromatid pair are aligned in the center of the cell.
What happens during anaphase? Hint: the sister chromatids no longer want to live together… again.
Sister Chromatids separate from each other at centromere and move away from each other toward opposite poles of the cell.
What happens during telophase? Hint: the spindle gives up on the sisters because of the separating, moving in, and separating again. The sisters can’t set aside their differences this time, so they form a N _ _ _ _ _ r E _ _ _ _ _ _ e around the set of chromosomes at each pole.
The spindle is dismantled. A nuclear envelope forms around the set of chromosomes at each pole. The chromosomes begin to de-condense. The nucleolus reappears.
