Chromosomes And Mitosis Pg.15 🩵

Question 1

In order to survive and grow, our cells have got to be able to ______.

Answer 1

Divide.

Question 2

_______ contain genetic information.

Answer 2

Chromosomes.

Question 3

The nucleus of a cell contains _______.

Answer 3

Chromosomes.

Question 4

Chromosomes are _______ ____ lengths of _____ molecules.

Answer 4

Coiled up.
DNA.

Question 5

Each chromosome carries a ______ number of genes.

Answer 5

Large.

Question 6

Different genes control the development of different ___________ e.g. hair colour.

Answer 6

Characteristics.

Question 7

______ ______ normally have ____ copies of each chromosome.

Answer 7

Body cells.
Two.

Question 8

There are ___ pairs of chromosomes in a human cell.

Answer 8

23.

Question 9

The cell cycle makes _____ _____.

Answer 9

New cells.

Question 10

Body cells in multicellular organisms (e.g. you, me or a plant) _____ to make new cells. This is part of a series of stages called the ____ ______.

Answer 10

Divide.
Cell cycle.

Question 11

What’s the stage of the cell cycle called when the cell divides?

Answer 11

Mitosis.

Question 12

Multicellular organisms use mitosis to ______ and _______.

Answer 12

Brown and develop.

Question 13

Before it divides:
1. The cell grows and increases the amount of ________ ________ such as ribosomes and mitochondria.
2. The DNA is ________ - so there’s one copy for each new cell.
3. The DNA forms __-_____ chromosomes. Each arm of the chromosome is an ______ ______ of the other.

Answer 13

Subcellular structures.
Replicated.
X-shaped.
Exact copy.

Question 14

The cell is now ready to divide…
4. The chromosomes ______ ___ at the _______ of the cell.
5. The ___ arms of each chromosome are ________ _______ to opposite ends of the cell.
6. This divides the _______.
7. Each set of chromosomes become the nucleus of a _____ ______.
8. The ________ and cell membrane divide.

Answer 14

Line up.
Centre.
Two.
Pulled apart.
Nucleus.
New cell.
Cytoplasm.

Question 15

A student looks at cells in the tip of a plant root under a microscope. She counts 11 cells that are undergoing mitosis and 62 cells that are not.
a) calculate the percentage of cells that are undergoing mitosis.
b) suggest how the student can tell whether a cell is undergoing mitosis or not.

Answer 15

a) 15%
b) she could she the X-shaped chromosomes in the middle of the cells.
OR
she could see the arms of the chromosomes being pulled apart.

Question 16

What happens in stage 1 of mitosis?

Answer 16

The cell is resting but still making more organelles.

Question 17

What also happens in stage 1 of mitosis?

Answer 17

The cell doubles the DNA and the components each new cell will need such as the mitochondria.

Question 18

What happens in stage two of mitosis?

Answer 18

The DNA condenses into the X shape and lines up in the middle of the nucleus and it then breaks down.

Question 19

What also happens in stage 2 of mitosis?

Answer 19

The condensed chromosomes are pulled apart and move to opposite ends of the cell.

Question 20

What happens in stage three of mitosis?

Answer 20

The nucleus form around the separated DNA and the cell divides into two genetically identical cells.

Question 21

What happens at the end of the mitosis cycle?

Answer 21

The DNA unpacks and the cycle starts again with another phase of cell growth.