2.3 Cell Division

Question 1

An important activity of all kinds of cells

Answer 1

Cell division

Question 2

The division of cells in animals body
Allows animals ( and us) to grow
Replaced old cells that die

Answer 2

Mitosis

Question 3

Produce two diploid (2n) somatic cells that are genetically identical to each other and the original parent cell

Answer 3

Mitosis

Question 4

Before a dividing cell enters mitosis, it undergoes a period of growth called interphase. About 90 percent of a cell’s time in the normal cellcycle may be spent in interphase.

This is the non-mitotic stage.

Answer 4

Interphase

Question 5

The period prior to the synthesis ofDNA. In this phase, the cell increases in mass in preparation for cell division.

The first gap phase

Answer 5

G1 phase

Question 6

The period during whichDNA is synthesized.

Answer 6

S phase

Question 7

The period after DNA synthesis has occurred but prior to the start of prophase

Answer 7

G2 phase

Question 8

During this period structural changes of chromosomes are visible.

Answer 8

M phase

Question 9

M phase may be subdivided into four stages,

Answer 9

Prophase, Metaphase, Anaphase and Telophase

Question 10

This stage is characterized by the appearance of coiled, contracted threads – the chromosomes. The chromosomes are longitudinally double, each half is a chromatid. The chromatin condenses into discrete chromosomes.

Answer 10

Prophase

Question 11

the spindlereaches maturity and the chromosomes align at the metaphase plate

Answer 11

Metaphase

Question 12

the paired chromosomes (sister chromatids) separate and begin moving to opposite ends (poles) of the cell.

Answer 12

Anaphase

Question 13

is accomplished by the formation of a cell plate, as the chromosomes separate during anaphase, the cytoplasm divides and the cytoplasmic contents are distributed.

Answer 13

Cytokinesis

Question 14

In sexually reproducing organisms, the special kind of cell division whereby the chromosomes number of the cells is reduced to half its usual number.

Answer 14

Meiosis

Question 15

This process, in which homologous chromosomes trade parts is called

Answer 15

Crossing over

Question 16

It helped along by a protein structure called the

Answer 16

Synaptonemal complex

Question 17

occur when there is a defect in a chromosome, or in the arrangement of the genetic material on the chromosome.

Answer 17

Chromosomal abnormalities

Question 18

can be in the form of additional material which may be attached to a chromosome, or where part or a whole chromosome is missing, or even in defective formation of a chromosome.

Answer 18

Abnormalities

Question 19

There are two main types of chromosomal abnormality which can occur during meiosis and fertilization:

Answer 19

numerical aberrations
structural aberrations

Question 20

These are usually caused by a failure of chromosome division, which results in cells with an extra chromosome or a deficiency in chromosomes.

Answer 20

Numerical aberration

Question 21

These occur due to loss or genetic material or a rearrangement in the location of the genetic material

Answer 21

Structural Aberrations

Question 22

What are the structural Aberrations?

Answer 22

1. Deletion
2. Duplication
3. Translocation
4. Inversions
5. Rings
6. Isochromosome

Question 23

is a type of eukaryotic cell that lacks a cell wall and has a true, membrane-bound nucleus along with other cellular organelles.

Answer 23

Animal cell

Question 24

contains the specific instructions that make each type of living creature unique

Answer 24

DNA

Question 25

are thread-like structures located inside the nucleus of animal and plant cells. Each chromosome is made of protein and a single molecule of deoxyribonucleic acid (DNA)

Answer 25

Chromosomes

Question 26

This is the basic physical and functional unit of heredity. Genes are made up of DNA.

Answer 26

Genes

Question 27

This is one of a pair of genes that appear at a particular location on a particular chromosome and control the same characteristic, such as blood type or color blindness. 

Answer 27

Alleles

Question 28

The organism's complete set of DNA, that contains all of the information needed to build and maintain that organism.

Answer 28

Genome