sb2

Question 1

What happens in prophase?

Answer 1

Nucleus breaks down and spindle fibres appear

Question 2

What happens in metaphase?

Answer 2

Chromosomes line up in centre of cell and attach to the spindle fibres

Question 3

What happens in anaphase?

Answer 3

Chromosome copies are pulled to either end of the cell by the spindle fibres

Question 4

What happens in telophase?

Answer 4

• nuclear membrane forms around each sets of chromosomes
• separates them from each other

Question 5

What happens in cytokinesis?

Answer 5

A cell surface membrane forms, separating the two cells

Question 6

What is the importance of mitosis?

Answer 6

It produces new body cells for growth and replacing damaged cells

Question 7

Describe the division of cells by mitosis and what it produces

Answer 7

• One cell divides once
• Produces two daughter cells, each diploid and genetically identical

Question 8

Describe cancer

Answer 8

Result in changes of cells that lead to uncontrolled cell division

Question 9

Describe growth in animals

Answer 9

• cell division
• cell differentiation

Question 10

Describe growth in plants

Answer 10

• cell division
• elongation
• cell differentiation

Question 11

What is the importance of cell differentiation

Answer 11

Gives cells a special function

Question 12

Function of embryonic stem cells

Answer 12

• they can differentiate into any type of cell in the body
• can be used to replace damaged cells e.g insulin producing cells for type 2 diabetes

Question 13

Function of meristems

Answer 13

• can differentiate into any type of plant
• can be used to make clones of the plant (this can be done to save a rare plant from extinction)

Question 14

Benefits and risks of research with stem cells

Answer 14

benefits:
- can be used to replace damaged or deceased body parts
- unwanted embryos could be used instead of being discarded
- process of differentiation

Risks:
- removal of stem cells causes destruction of embryo
- people may have religious or ethical objections
- if growing stem cells have virus, an infection can be transferred to person

Question 15

Function of cerebellum

Answer 15

• found at bottom of brain
• responsible for controlling fine movements of muscles

Question 16

Function of cerebral hemispheres

Answer 16

• divided into 2 hemispheres
• right hemisphere controls left side of body and vice versa
• controls senses/memory/thought/emotions

Question 17

Function of medulla oblongata

Answer 17

• neurones here connect brain to spinal cord
• responsible for ‘automatic functions’ like breathing/digestion/heart rate

Question 18

How do PET scans work

Answer 18

Uses radioactive glucose to see which areas of the brain will take it in

Question 19

What happens in CT scans

Answer 19

• fire x ray radiation at the brain to generate 3D image of brain
• shows brain structures

Question 20

Why is treating the brain difficult?

Answer 20

• it is surrounded by skull
• risk of damage to brain
• not fully understood which part of the brain does what
• tumours can be buried deep in brain which makes it difficult to remove

Question 21

what is the function of sensory neurones?

Answer 21

• transmits electrical impulses
• from receptors to the CNS