BIOLOGY 151 Lecture Notes - Lecture 9: Metaphase, Mitosis, Cell Growth

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amaranthmarten130

12 Oct 2015

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Document Summary

G0: cell usually in quiescent state, it is resting as soon as it leaves the cycle and stops: g1: more activity. Cell increases supply of proteins, increases organelles, and grows in dividing. size. Cell cycle phases: s-phase: dna replication, it is completed quickly, m-phase: mitosis: prophase, metaphase, anaphase, and telophase, cytokinesis: cytoplasm divides into two daughter cells. Regulation of eukaryotic cell cycle: cyclins and cdks: when cyclin binds to cdks, they perform phosphorylation that activates/inactivates target proteins that coordinate entry into the next phase of the cell cycle. Inhibitors (tumor suppressors): p21, p27, and p57: stop cell cycle in g1 by binding to it and inactivating c-cdks, p16ink4a: binds to cdk4 and stops the cell cycle in g1. Checkpoints: g1 checkpoint: energy, mutations/damage, carbon/nitrogen, social signals, size, g2 checkpoint: preparation for m and growth, check for replication and damage, m checkpoint: chromosome segregation. Tumor formation: proto-oncogenes: usually caused by gain-of-function mutations, where proto- oncogenes become oncogenes.

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

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Question 3 (5 points)

Match the terms to the definitions provided.

Question 3 options:

	telophase II
	meiosis II
	telophase I
	anaphase I
	anaphase II

1.	Division, beginning without DNA replication, that resembles and produces four haploid cell.s
2.	Phase of meiosis when chiasmata are broken as spindle fibers shorten and homologous pairs are pulled apart.
3.	Phase of meiosis when sister chromatids are pulled to opposite poles of the cells.
4.	Phase of meiosis in which homologues cluster at the poles of the cells and the nuclear envelope reforms.
5.	Phase of meiosis in which four different haploid cells are present.

Question 4 (7 points)

Match the terms to the definitions provided.

Question 4 options:

	G0
	telophase
	G2
	mitosis
	cytokinesis
	cell cycle
	S

1.	The phase in which the cell synthesizes a replica of its genome
2.	The overall process of genome duplication
3.	The phase in the cell cycle during which mitochondria and other organelles replicate.
4.	The phase in mitosis when chromosomes are clustered at opposite poles and the spindle apparatus disappears
5.	A resting state that cells often enter before resuming cell division.
6.	The phase in the cell cycle when the cytoplasm divides creating two daughter cells.
7.	The phase in the cell cycle in which the spindle apparatus assembles and sister chromatids move apart.

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Question 5 (6 points)

Put the events of a MAP kinase cascade in the correct order.

Question 5 options:

	MAPKKK phosphorylates and activates another kinase
	MAPKK phosphorylates and activates MAPK
	Binding of MAPKKK to Ras
	External signal binds to membrane receptor and activates receptor kinase.
	MAPK phosphorylates an inactive response protein and activates it.
	Phosphorylation of receptor kinase and interaction with RAS