SB2

Question 1

1) haploid cell + example
2) diploid cell + example

Answer 1

1) haploid - cells with 1 copy of each chromosome (eg. gametes)

2) diploid - cells with 2 copies of each chromosome (eg. adult humans)

Question 2

1) stage before + after mitosis
2) mitosis

Answer 2

1) before - interphase
after - cytokinesis

2) mitosis - PMAT

Question 3

1) how asexual reproduction happens
2) pros / cons

Answer 3

1) through mitosis

2) pros - faster, share resistance
cons - no variation, share weakness

Question 4

how do cancer cells grow

Answer 4

cells undergo rapid, uncontrollable cell division

Question 5

define + explain growth

Answer 5

an increase in the size / number of cells
through mitosis

Question 6

define + explain meristem cells

Answer 6

allow plants to keep growing
through mitosis

Question 7

plant growth equation

Answer 7

(final - starting value) ÷ starting value
x100

Question 8

1) define stem cells
2) why we need them
3) how can they treat disease
4) two problems

Answer 8

1) cells that divide repeatedly over a long period of time

2) for human growth and to replace old / damaged tissues

3) can treat disease by being stimulated and injected where needed

4) uncontrolled division can lead to cancer
and cells can be rejected by person they’re put into

Question 9

cell differentiation

Answer 9

cells that have changed to be specialised

Question 10

1) nuerones
2) their function

Answer 10

1) interconnect with nuerones and body parts

2) process information and control the body

Question 11

1) cerebral cortex
2) it’s function

Answer 11

1) two cerebral hemispheres - R + L communicate

2) for senses, language, memory, behaviour and consciouness

Question 12

1) cerebellum + function
2) who may have developed cerebellums

Answer 12

two halves - controls muscle action, posture and balance

musicians

Question 13

1) medulla oblongata + function

Answer 13

1) neurons connect brain to spinal cord
2) controls heart and breathing rate +
reflexes (eg. sneezing)

Question 14

1) ct scan
2) pet scan

3) radiotherapy + chemotherapy
4) their problems

5) spinal cord problems

Answer 14

1) ct - brain shape and structure
2) pet - brain activity

3) radio and chemotherapy - kill cancer cells

4) both - can damage body/brain and may not work

5) no current fix for spinal cord problems

Question 15

1) Central Nervous System (CNS)
2) Nervous system
3) The nervous system’s function

Answer 15

1) CNS - made of brain and spinal cord

2) Nervous system - made of nerves
3) allows body parts to communicate through impulses

Question 16

1) Stimulus
2) How the body responds

Answer 16

1) anything the body is sensitive to
2) Receptor cells form an impulse –> brain –> brain sends an impulse to the body –> body responds

Question 17

1) Another word for Nerve Cells
2) Neurotransmission
3) Where it occurs

Answer 17

1) Nuerones
2) The travel/ transmission of impulses
3) Occurs in neurones

Question 18

1) How are dendrons + axons adapted
2) What is the Myelin Sheath
3) What does the Myelin Sheath do

Answer 18

1) They are long for fast neurotransmission
2) Fatty layer surrounding sensory neurones
3) Allows for faster neurotransmission, insulates the cell preventing the signal losing energy

Question 19

examples of sense organs

Answer 19

eyes, ears, skin

Question 20

1) Retina + what it contains
2+3) Define the two things it contains + 4) Link to vision in darkness

Answer 20

1) Layer of rods + cones, contains receptor cells
2) Cones - receptor cells sensitive to the colour of light - mainly for bright light
3) Rods - receptor cells sensitive to differences in light intensity - mainly for dim light

4) Rods don’t detect colour so that’s why we don’t see colour well in the dark

Question 21

1) Pupil
2) Iris
3) How the iris performs it’s role
4) It’s importance

Answer 21

1) Where light enters
2) Controls amount of light entering the eye
3) Constricts/ Dilates the pupil to adjust the amount of light that can enter
4) Bright light can damage the retina

Question 22

1) Cornea
2) Lens
3) Ciliary Muscles

Answer 22

1) Vision Focus
2) Finer focussing
3) Control lens for vision depending on distance

Question 23

Solutions for Eye Problems
1) Short sight
2) Long sight
3) Cataract
4) Colourblindness

Answer 23

1) Diverging Lens
2) Converging Lens
3) Replace Lens
4) No Fix

Question 24

1) motor neurones
2) relay neurones
3) Synapse

Answer 24

1) carry impulses to effectors
2) link motor + sensory neurones
3) where neurones meet

Question 25

1) Reflex actions
2) Why Reflex actions occur
2) Reflex Arc

Answer 25

1) Automatic/ quick actions which don’t require thought processing
2) Occur to protect the body
3) Neurone Pathway for reflex actions to occur