Biology Paper 1 - Topic 2: Cells & Control - Flashcards in GCSE Biology

What are the stages of the cell cycle?

- Interphase - cell grows and sub-cellular organelles are duplicated
- Mitosis
- Cytokinesis - Separate cell membrane and cytoplasm forms

1 of 27

What are the stages of mitosis?

Prophase - Cell membrane breaks down and spindle fibres appear
Metaphase - The chromosomes lines up along the centre of the cell
Anaphase - The spindle fibres pull the chromosomes to opposite poles
Telophase - Membrane forms around each set of chromosomes

2 of 27

1) Definition of mitosis
2) What is it needed for?

1) Cell division which produces two genetically identical haploid daughter cells to the parent
2) Growth, repair, asexual reproduction

3 of 27

What is cancer?

A non-communicable disease as a result of changes in the cell that damage DNA which lead to uncontrollable cell division

4 of 27

Describe growth in animals

- Cell division occurs in all body cells. It occurs faster in young animals as adults only need it for growth and repair
- Most cells become specialised at an early stage. Adult stem cells are limited in what they can differentiate into

5 of 27

Describe growth in plants

- Cell division only occurs in meristematic tissue. The rate of cell division remains the same throughout a plant's life
- Meristematic stem cells can differentiate into any cell type for as long as the plant lives
- Cell elongation occurs enabling growth

6 of 27

Why is cell differentiation important?

- It enables the formation of specialised tissue with specific functions e.g. muscle tissue

7 of 27

What are the benefits of using stem cells in medicine?

- Can be used to treat otherwise untreatable conditions e.g. spinal cord damage
- Used for scientific research
- Growing organs for transplants

8 of 27

What are the risks associated with using stem cells?

- Transplanted cells can cause tumours
- Stem cells may be rejected
- May need to take immunosuppressant drugs (which risks infection from other pathogens)
- Stem cells may become infected doing more harm than good
- Ethical/moral reasons against them

9 of 27

What makes up the nervous system?

* Brain
* spinal cord - neurones which extend down the spine from the medulla oblongata to connect the peripheral nervous system to the brain

10 of 27

What are the 3 regions of the brain
* to know for GCSE?

1) Cerebrum - Thick upper part
2) Cerebellum - Bottom back of the brain
3) Medulla Oblongata - The part that extends downward (towards the spine)

11 of 27

Describe the cerebrum

- Involved in conscience aspects such as intelligence, language, memory and emotion
- It's divided into two hemispheres
- Left hemisphere receives sensory info from the right part of the body and controls muscles there
- The right hemisphere does the same

12 of 27

Describe the cerebellum

- Involved in coordination of muscle, balance and walking

13 of 27

Describe the medulla oblongata

- Controls automatic processes in the body e.g. breathing rate, heart rate and peristalsis

14 of 27

What can doctors do to observe the brain
*that we learn at GCSE?

- CT scan (Computerised tomography)
- PET Scan (Positron Emission Tomography)

15 of 27

Describe CT scans

- X-rays are used to produce 3D cross-sectional images of the brain
- By comparing the patient's brain to a healthy brain, they can see where damage like bleeding or swelling occurs

16 of 27

Describe PET scans

- Radioactive substance is injected into the patient and their brain tissues take them up
- Radiation is emitted and we can see which parts of the brain are active or aren't
- Comparison with healthy person's brain can be made to determine damage

17 of 27

Why is it difficult to treat CNS damage?

- Nerve cells don't divide by mitosis so neurone damage is permanent
- Hard to reach certain areas of the brain without damaging healthy parts

18 of 27

1) Describe axons
2) Describe dendrites & dendrons

1) Carries impulses away from the cell body and enables transmission over long distances
2) Both carry electrical impulses towards the cell body but dendrites are smaller but more numerable to provide larger surface area for impulses

19 of 27

Describe the myelin sheath

- Electrical insulating layer which surrounds axons to increase impulse speed

20 of 27

Describe the sensory neurone

- Impulses go from receptors to CNS
- Long dendron carries impulse from receptor to the cell body part way along the neurone
- Short axon carries impulse from the cell body to the CNS

21 of 27

Describe the motor neurone

- Carries impulse from the CNS to the effectors
- Short dendrites carry impulses from the CNS to the cell body found at one end of the neurone
- Long axon carries impulse from the cell body to the effectors

22 of 27

Describe the relay neurone

- Carries impulses from sensory neurones to motor neurones within the CNS
- Short dendrites carry impulses away from the sensory neurones to the cell body
- Short axons carries impulses from the cell body to motor neurones

23 of 27

Describe how the CNS responds to a stimulus

- Stimulus
- Sensory receptor
- CNS
- Effector
Response

24 of 27

What is a synapse?

- A small gap between neurones across which a nerve impulse is transmitted via neurotransmitter chemicals

25 of 27

Describe how nerve impulses are transmitted across a synapse

- The impulse reaches the presynaptic neurone
- Neurotransmitters are released
- They diffuse across the synaptic cleft
- They bind to receptors on the postsynaptic neurone
- This stimulates an impulse in the postsynaptic neurone

26 of 27

Outline the reflex arc

Stimulus > Sensory receptor> Sensory neurone> Relay neurone > Motor neurone > Effector
> Response

27 of 27

Get Revising

Biology Paper 1 - Topic 2: Cells & Control

Other cards in this set

Card 2

Front

Back

Card 3

Front

Back

Card 4

Front

Back

Card 5

Front

Back

Comments

Similar Biology resources:

Other cards in this set

Card 2

Front

Back

Card 3

Front

Back

Card 4

Front

Back

Card 5

Front

Back

Comments

Related discussions on The Student Room

Similar Biology resources: