Topic 2- Cells and control

Question 1

What do chromosomes contain ?

Answer 1

genetic material

Question 2

Explain the process of mitosis:

Answer 2

Card 15

Question 3

What is cell differentiation?

Answer 3

Is when a cell changes to become specialised for its function and allows multicellular organisms to work more efficiently .

Question 4

What is cell elongation?

Answer 4

Is where the cells of the plant expand making it grow.

Question 5

What is mutation?

Answer 5

A random change in a gene

Question 6

Explain how cancer is formed through cell division\\

Answer 6

If there is a change in a gene that controls cell division then the cell may start dividing uncontrollably which may lead to tumour and lead to cancer.

Question 7

What cell can differentiate into any other type of cell?

Answer 7

Stem cells

Question 8

Where does cell division happen?

Answer 8

In meristems - tips of the root and top of the shoots

Question 9

What are undifferentiated cells called?

Answer 9

stem cells

Question 10

Where are stem cells found?

Answer 10

In early human embryo , adults also have them and they are found in bone marrow.

Question 11

What do meristems produce?

Answer 11

Unspecialised cells

Question 12

What do unspecialised cells turn into ?

Answer 12

Xylem and phloem

Question 13

Explain the risks of stem cells in medicine:

Answer 13

1, Tumour development - they divide quickly and scientists may not be able to control them
2, Disease transition
3, Rejection - your body may identify them as foreign and have an immune response

Question 14

What does the cerebellum in the brain control?

Answer 14

Muscle coordination and balance

Question 15

What does medulla oblongata contol?

Answer 15

unconscious activities such as heart rate and breathing

Question 16

Which scanners can be used to investigate brain function?

Answer 16

CT scanning-uses x-rays , shows main structure of the brain but does not show its main functions
PET scanners- very details uses radioactive chemicals can can show both structures and functions

Question 17

Name in order the central nervous system responses:

Answer 17

Stimulus
Receptor
Sensory neuron
Relay neuron 
Motor neuron 
Effector
Response

Question 18

Explain what a myelin sheeth used for

Answer 18

it acts as an electrical insulator speeding up the electrical impulse

Question 19

Sensory neuron contains…

Answer 19

Long dendrites and short axons

Question 20

Motor neuron contains…

Answer 20

Many short dendrites

One long axon

Question 21

Relay neuron contains…

Answer 21

Many short dendrites

An axon

Question 22

What is the connection between two neurons called?

Answer 22

synapse

Question 23

What chemical transfers the nerve signal?

Answer 23

neurotransmitters

Question 24

What slows down the impulse ?

Answer 24

the synapse , causes a gap and diffusion takes time

Question 24

What slows down the impulse ?

Answer 24

the synapse , causes a gap and diffusion takes time

Question 25

Explain how reflex helps to protect your eye?

Answer 25

Light receptors in the eye help detect bright light and send the message to the brain along the sensory neuron.

Question 26

Explain how a structural problem with the eye may cause a person to be long-sighted?

Answer 26

The lens may be the wrong shape or the eyeball might be too short , meaning light from near objects is brought into focus behind the retina.

Question 27

Explain why short-sighted people can't see far

Answer 27

Because the lens is the wrong shape and bends light too much or the eyeball is too long. So light is bought in front of the retina

Question 28

Function of cornea

Answer 28

refracts (bends) light into they eye

Question 29

Function of an iris

Answer 29

Controls how much light enters the pupil

Question 30

Function of an lens

Answer 30

Also refracts light focusing it onto retina