1) Cells and Control

Question 1

what are diploid cells?

Answer 1

sex cells with only 23 sets of chromosomes

Question 2

what are the different stages of mitosis in order?

Answer 2

• interphase
• prophase
• metaphase
• anaphase
• telophase
• cytokinesis

Question 3

what happens in interphase?

Answer 3

each set of chromosome make a copy of their selves

Question 4

what happens in prophase?

Answer 4

• nucleus breaks down

- spindle fibres appear

Question 5

what happens in metaphase?

Answer 5

• chromosomes are lined up on spindle fibres

- in the middle

Question 6

what happens in anaphase?

Answer 6

• chromosomes are separated

- on either side of cell

Question 7

what happens in telophase?

Answer 7

-membrane forms to get nuclei

Question 8

what happens in cytokinesis?

Answer 8

• cell membrane forms to set separate cells

- cell walls form in plant cells

Question 9

why is mitosis important?

Answer 9

• growth
• repair
• asexual reproduction

Question 10

how can changes in cell growth result in cancer?

Answer 10

• go under uncontrollable division
• forms growing lumps
• causes tumours
• damage the body; death

Question 11

what is differentiation in animals?

Answer 11

• mitosis makes identical cells which are for the same purpose
• some aren’t specialised
• so some change from less specialised into more specialised cells CALLED DIFFERENTIATION

Question 12

how are percentile charts used to monitor growth?

Answer 12

• large number of people measured
• divided into groups of 100
• which relate to a percentage

Question 13

what is the function of embryonic stem cells in animals?

Answer 13

-cells in an embryo which are turn into any type of specialised cell

Question 14

what is the function of meristem in plants?

Answer 14

• small group of cells at the end of a shoot
• allowing it to grow
• divide rapidly
• elongate and differentiate into specialised cells

Question 15

what are the benefits of stem cells in medicine?

Answer 15

• way of treating diseases cured by damaged cells

- help cure type 1 diabetes

Question 16

what are the problems with stem cells in medicine?

Answer 16

• cause cancer

- the can be killed by immune system. (rejection)

Question 17

what forms the central nervous system(CNS)?

Answer 17

brain and spinal chord

Question 18

what does the nervous system allow the body to do?

Answer 18

• communicate

- using electrical signals (impulses)

Question 19

what is a stimulus?

Answer 19

anything your body is sensitive to i.e. temperature

Question 20

what are sense organs and what do they contain?

Answer 20

• eyes, ears, skin

- contain receptor cells that detect stimuli

Question 21

what do receptor cells do?

Answer 21

crew impulses that go to the brain

Question 22

what are neurotransmissions?

Answer 22

-travelling or transmission of impulses

Question 23

what is a sensory neurone?

Answer 23

-neurone carrying receptor cells

Question 24

where do the impulses travel?

Answer 24

• branch calle dendrite

- along DENDRON and AXON

Question 25

how are dendrons and axons adapted?

Answer 25

- long so its fast | - fatty lajrecalled MYELIN SHEATH

Question 26

what are motor neurones?

Answer 26

-carry impulses to effectors

Question 27

what are relay neurones and what do they do?

Answer 27

- short - found in spinal chord - link motor and sensory neurones - make up lot of tissue in the brain

Question 28

what is a synapsis and wha does it do?

Answer 28

- tiny gap between each neurone - chemical is released into the gap - sow down neurotransmission

Question 29

what are reflex arcs and what do they do?

Answer 29

- automatic responses - protect the body - use pathways called reflex arcs which bypass the brain