BIOB11H3 Lecture Notes - Lecture 15: G2 Phase, Heterokaryon, S Phase

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greymouse967

3 Mar 2017

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Document Summary

Mitosis: division of nuclear material // cytokinesis: division of cytoplasm. Consider an asynchronous cell culture (cells in different cell cycle, some in g1, some in s, some in m etc) Add 3h-thymidine, label 15 min, fix and conduct autoradiography / count cells which are radiolabelled. 9/30 cells are labelled 30% are in s phase 30% of the cell cycle is in s phase. *dna replication occurs in s phase hence 3h-thymidine will be incorporated into dna. Asynchronous cells: label with radioactive dntp for short time incorporation of label only occurs in s phase. Examine cells at later times for mitotic chromosomes (condensed) check are the mitotic chromosomes labelled. *the first mitotic chromosomes to appear will not be labelled it was far beyond s phase and no new dntp* will be incorporated. Add 3h-thymidine for 30 minutes to an asynchronous culture. Time between start of labeling period to appearance of the first labelled mitotic chromosome.

Related Questions

Part A:

In prokaryotes and eukaryotes cell reproduction is similar in that it requires some kind of signal to proceed, DNA replication, careful separation of the DNA into two equal portions, and division of the cytoplasm. How is cell reproduction different in prokaryotes and eukaryotes?

Select one:

a. In a eukaryotic organism, the signals for cell division are usually not related to the environment but to the function of the entire organism.

b. Eukaryotic cells constantly divide whenever environmental conditions are adequate and the cells are large enough.

c. The linear chromosomes in prokaryotes are constantly being updated.

d. Prokaryotic cell division requires cytokinesis before mitosis because of their small size.

e. The sexual phase of most prokaryotes (bacteria) is essential to the rapid cell division required for infection.

Part B:

What does the name Cyclin Dependent Kinase stand for?

Select one:

a. A protein important to the cell cycle that is dependent on DNA synthesis.

b. An enzyme that cuts DNA so that chromosomes can segregate.

c. An enzyme that phosphorylates other proteins using ATP only when the protein Cyclin is bound to the enzyme.

d. An enzyme that rolls along microtubules dragging a vesicle.

e. An enzyme that connects chromosomes to the spindle fiber.

Part C:

The Cell Cycle is divided into Mitosis, Cytokinesis, and Interphase. Mitosis can be ordered into the following phases:

Select one:

a. Prophase/Prometaphase/Metaphase/Anaphase/Telophase

b. Anaphase/Prometaphase/Metaphase/Prophase/Telophase

c. Metaphase/Anaphase/Telophase/Prophase/Prometaphase

d. Telophase/Prophase/Prometaphase/Metaphase/Anaphase

e. Anaphase/Telophase/Prophase/Prometaphase/Metaphase

Part D:

The Cell Cycle is divided into Mitosis, Cytokinesis, and Interphase. Interphase can be ordered into the following phases:

Select one:

a. S/G1/G2

b. G2/G1/S

c. G1/S/G2

d. G2/S/G1

e. G1/G2/S

amethystyak657

What function(s) does mitosis fulfill for multicellular organisms?

Match the phrase on the left with the part of the cell cycle on the right.

DNA replication is checked for accuracy