Biology (cells and control)

Question 1

How many chromosomes make up the human body?

Answer 1

2 copies of each 23 types- 46

Question 2

Prophase-

Answer 2

The chromosomes condense, getting shorter and fatter. The membrane around the nucleus breaks down and the chromosomes lie free in the cytoplasm.

Question 3

Metaphase

Answer 3

The chromosomes line up at the centre of the cell..

Question 4

Anaphase-

Answer 4

Cell fibres pull the chromosomes apart. The two arms of each chromosome go to opposite ends of the cell.

Question 5

Telophase-

Answer 5

Membranes form around around each of the sets of chromosomes. These become the nuclei of the two new cells- the nucleus has divided.

Question 6

Cytokines-

Answer 6

Before telophase ends, the cytoplasm and cell membrane divide to form two separate cells.

Question 7

Diploid cells-

Answer 7

Body cells normally have two copies of each chromosome.

Question 8

Prophase 2-

Answer 8

The nucleus starts to break down and spindle fibres appear

Question 9

Metaphase 2-

Answer 9

The chromosomes are lined up on the spindle fibres across the middle of the cell

Question 10

Anaphase 2-

Answer 10

The chromosome copies are separated and moved to either end of the cell on the spindle fibres.

Question 11

Telophase 2-

Answer 11

A membrane forms around each set of chromosomes to form nuclei

Question 12

Cytokinesis 2-

Answer 12

A cell surface membrane forms to separate the two cells. Cell walls form in plant cells?

Question 13

Asexual reproduction-

Answer 13

Some organisms can reproduce using just one parent. Produces offspring that are clones, which means that their cells have the same chromosome as the parent.

Question 14

Cell differentiation-

Answer 14

The process by which a cell changes to become specialised for its job. Having specialised cells allows multicellular organisms to work more efficiently.

Question 15

Growth charts-

Answer 15

Used to assess a child’s growth over time. Highlights problems such as obesity, malnutrition and dwarfism.

Question 16

What do the percentagesshow.

Answer 16

50% show that 50% of babies will have reached at a certain age.

Question 17

Cell elongation

Answer 17

His is where the plant cell expands, making the cell bigger and so making the plant grow.

Question 18

Formula for plant growth

Answer 18

Final value- starting value
Divide by starting value
Times by 100%

Question 19

Stem cells-

Answer 19

Undifferentiated cells

Question 20

In plants, the only cells that divide by mitosis are foundin plant tissues called…

Answer 20

Meristems.

Question 21

Rejection-

Answer 21

If the transplanted cells aren’t grown using the patients own stem cells, the patients body may recognise the cells as foreign and trigger an immune response to try to get rid of them the patient can take drugs to suppress this response.

Question 22

Sensory neurone

Answer 22

One long dendron carries nerve impulses from receptor cells to the cell body, which is located in the middle of the neurone.
One short axon carries nerve impulses from the cell body to the CNS.

Question 23

Motor neurone-

Answer 23

Many short dendrites carry nerve impulses from the CNS to the cell body.
One long axon carries nerve impulses from the cell body to effector cells.

Question 24

Relay neurone-

Answer 24

Any short dendrites carry nerve impulses from sensory neurones to the cell body.
An axon carries the nerve impulses from the cell body to motor neurones.

Question 25

Stimulus - receptor - sensory neurone - CNS - motor neurone - effector - response

Answer 25

.

Question 26

Reflexes-

Answer 26

Are automatic, rapid responses to stimuli- they can reduce the chances of being injured.

Question 27

Synapses-

Answer 27

The connection between two neurones is called a synapse.

Question 28

1. Impulses from receptor cells in the eye are transmitted by sensory neurones in the optic nerve to the brain processes these impulses and ‘sees’ the pencil.

Answer 28

2. The brain can send more impulses to tell to tell parts of the body to do something.