Chapter 8 Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

Why can a eukaryotic cells not simply split into two?

A

Because then only one daughter cell would inherit the nucleus and the DNA. A cell’s cytoplasm only splits after its DNA has been copied and packaged into more than one nucleus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is Mitosis?

A

Mitosis is a nuclear division mechanism that occurs in somatic (body) cells of multicelled organisms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is Meiosis?

A

The basis of sexual reproduction, in humans and mammals gametes (sperm and eggs) develop from immature reproductive cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Functions of Mitosis cytoplasm division (4).

A

In all multicelled eukaryotes, the basis of three processes:1. Increases in body size during growth2. Replacement of dead or worn-out cells3. Repair of damaged tissuesIn single-celled and many multicelled species, also thebasis of asexual reproduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Function of Meiosis cytoplasm division.

A

In single-celled and multicelled eukaryotes, the basis of sexual reproduction; precedes gamete formation or spore formation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Function of Prokaryotic fission.

A

In bacteria and archaeans alone, the basis of sexual reproduction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are Sister Chromatids?

A

Two attached molecules of DNA (attached as one chromosome)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are Histones?

A

“Spools” of proteins. Under a microscope appears as beads on a string.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are Nucleosomes?

A

A “bead” of a histone, the smallest unit of structural organization in eukaryotic chromosomes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a Centromere?

A

The constricted region of a sister chromatid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are Kinetochores?

A

Binding sites for microtubules that tether the chromatids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is a Cell Cycle?

A

A series of events from one cell division to the next. Consists of: mitosis, cytoplasmic division, and interphase.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is Interphase?

A

Interphase consists of three stages that increases the mass, doubles the cytoplasmic components, and duplicates the DNA of a cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the three stages of Interphase?

A
  1. G1 - Interval (Gap) of cell growth and activity before the onset of DNA replication.2. Time of “Synthesis” (DNA replication).3. G2 - Second interval (Gap) after DNA replication where the cell prepares for division.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the Chromosome Number?

A

The sum of all chromosomes in a cell of a given type.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the four stages of Mitosis?

A
  1. Prophase2. Metaphase3. Anaphase4. Telophase
17
Q

What is the Bipolar Spindle?

A

A dynamic network of microtubules the grows from opposite poles of the cell during prophase.

18
Q

What does “Mitos” mean?

A

Comes from the Greek word “thread”.

19
Q

What happens to two sister chromatids during prophase?

A

The duplicated chromosomes condense and become threadlike, and then rod-shaped. New microtubules assemble.

20
Q

What is a Centrosome?

A

A region near the nucleus that will organize microtubules while they are forming.

21
Q

When is the Centrosome duplicated?

A

Just before prophase.

22
Q

What happens in the early stages of prophase?

A

Mitosis begins. DNA and its associated proteins have started to condense. Two chromosomes were inherited from the female parent. Theother two are their counterparts,inherited from the male parent.

23
Q

What happens in the late stages of prophase?

A

The duplicated chromosomescontinue to condense. Newmicrotubules move one of twopairs of centrioles to the opposite side of the nucleus. The nuclear envelope starts to break up.

24
Q

What happens during the transition from prophase to metaphase?

A

Microtubules penetrate the nuclear region and collectively form a bipolar spindle. Some tether one sister chromatid of each chromosome to a spindle pole. Others overlap at the spindle equator.

25
Q

What happens during metaphase?

A

All of the chromosomes have become lined up midway between the spindle poles. At this stage of mitosis, the chromosomes are in their most tightly condensed form.

26
Q

What happens during anaphase?

A

Sister chromatids separate as motor proteins moving along spindle microtubules drag them to opposite spindle poles. Other microtubules push the poles farther apart.

27
Q

What happens during telophase?

A

There are two clusters of chromosomes, which now decondense. Patches of new membrane fuse to form a new nuclear envelope. Mitosis is over.

28
Q

What results at the end of mitosis?

A

After cytoplasmic division, there are two daughter cells. Each is diploid: Its nucleus has two of each type of chromosome, just like the parent cell.

29
Q

What are Kinases?

A

A class of enzymes that can activate other molecules by transferring a phosphate group to them. When DNA is broken or incomplete, kinases can activate certain proteins that eventually lead to cell death or stopping the cell cycle.

30
Q

What are Growth Factors (checkpoints)?

A

Checkpoint proteins that activate genes that stimulate cells to grow and divide.

31
Q

How is a tumour formed?

A

When a cell’s continually dividing descendants are not stopped by a checkpoint protein and abnormal mass is formed.

32
Q

What are Neoplasms?

A

Moles and other tumours, or abnormal masses of cells that lost control over how they grow and divide.

33
Q

What are Cancers?

A

Abnormally growing and dividing cells of a malignant neoplasm, they physically and metabolically disrupt surrounding tissues.