Chp 10 Cell dividion Flashcards | Quizlet

What is septation?

The formation of cross walls between daughter cells.

Who discovered mitosis?

Walter Flemming.

What is the typical range of chromosomes for eukaryotes?

$$10\text{--}50$$

What are nucleosomes?

DNA-histone complexes.

Which four proteins make up the core histones?

H2A, H2B, H3, and H4.

Which eukaryotic histone protein interacts directly with linker DNA?

H1

What is the typical length of linker DNA?

$20$ to $80\,\text{bp}$

Which two amino acids are prominent in histone proteins?

Arginine and lysine.

What is the first step of bacterial binary fission?

DNA replication begins at the origin of replication.

What is the duration of the shortest cell cycle, found in fruit flies?

$$8\,\text{mins}$$

How long does an animal embryo take to complete a cell cycle?

$$20\,\text{mins}$$

How long does a dividing mammalian cell take to complete its cell cycle?

$$24\,\text{hr}$$

In a mammalian cell, what proportion of the cell cycle is taken up by mitosis?

A small fraction, about $5\%$

Which organelle absorbs the components of the nuclear envelope when it breaks down?

The ER (endoplasmic reticulum).

What is the function of interpolar microtubules during mitosis?

They push the poles of the cell away from each other and overlap in the center.

What substance coats newly formed cell plates during plant cytokinesis?

Cellulose.

What are the three major checkpoints of the cell cycle?

G1/S, G2/M, and the Spindle checkpoint.

In what organisms were cyclins first discovered?

In the embryos of sea urchins.

In yeast division, which gene is required for two checkpoints and what type of protein does it encode?

cdc2, which encodes a protein kinase.

What does the acronym MPF stand for?

Maturation/mitosis promoting factor.

What enzyme activates MPF by removing inhibitory phosphates from its kinase component?

Phosphatase.

Which types of human cells permanently remain in and never leave the G0 phase?

Muscle cells and neuron cells.

What is the function of the p53 protein?

A tumor-suppressor protein that responds to DNA damage by stopping the cell cycle and triggering apoptosis (cell death).

How does the APC/C (cyclosome) trigger the separation of sister chromatids?

By marking the protein securin for degradation.

What are the five sequential stages of mitosis?

Prophase, prometaphase, metaphase, anaphase, and telophase (PPMAT).