Section 2.1 Cell Division Growth and Differentiation

Question 1

Why do worn out or damaged cells need to be replaced by new cells with the same genetic information as the originals?

Answer 1

So they can carry out the same function

Question 2

What are chromosomes?

Answer 2

Chromosomes carry genes that contain the instructions for making both new cells and all the tissues and organs needed to make an entire new you

Question 3

Where are chromosomes found?

Answer 3

In the nucleus

Question 4

What is a gene?

Answer 4

a small section of DNA that controls a characteristic, or part of a characteristic, of your body.

Question 5

Where are genes found?

Answer 5

In the chromosomes

Question 6

What are alleles?

Answer 6

Different forms of the same gene

Question 7

How many chromosomes are found in the nucleus?

How many pairs of chromosomes are there in a cell

Answer 7

46 chromosomes

23 pairs, one pair is inherited from you dad and the other from you mom

Question 8

What is mitosis?

Answer 8

Cell division which results in two identical daughter cells (same genetic information).

Question 9

Why does mitosis take place?

Answer 9

To produce cells needed for growth or replacement.

Question 10

In which type of reproduction is mitosis used?

Answer 10

Asexual reproduction

Question 11

Why is there no genetic variation in asexual reproduction?

Answer 11

Asexual reproduction produce offspring with mitosis. Therefore the genetic information and alleles of the parent and offspring are the same and there is no genetic variation.

Question 12

How does mitosis work?

Answer 12

Before the cell divides, it produced new identical copies of its chromosomes in the nucleus. The cell then divides ONCE to form TWO genetically identical cells

Question 13

What are unspecialised cells called?

Answer 13

Stem cells

Question 14

What does differentiation mean?

Answer 14

When an undifferentiated (unspecialised) cell (stem cell) differentiates it becomes specialised to perform a particular function.

Question 15

Are most of the cells in animals differentiated or not?

Answer 15

The majority of the cells in an animal are differentiated, there are few adult stem cells

Question 16

Are most of the cells in plants differentiated or not?

Answer 16

The majority of cells in plants are NOT differentiated and are able to differentiate all through their lives.

Question 17

Can plant cells redifferentiate?

Answer 17

Yes they can, this mean that even though they have differentiated, you can remove the cell and move it to another part of the plant and it will become a different type of cell. This DOES NOT occur in animal cells

Question 18

What is producing identical offsprings known as?

Answer 18

Cloning

Question 19

Is is difficult to clone plants? Why or why not?

Answer 19

It is easy to clone with plants as their cells can differentiate and redifferentiate throughout their lives

Question 20

Is is difficult to clone animals? Why or why not?

Answer 20

It is difficult to clone animals as their cells differentiate permanently early in the embryo development. Animal clones can only be made by cloning embryos and by using special techniques on the nuclei of adult cells