B2 CELLS AND CONTROL

Question 1

What is the cell cycle

Answer 1

The life of a cell comprising interphase and mitosis

Question 2

What is interphase

Answer 2

Preparation for mitosis in which extra cell parts are made and DNA chromosomes are replicated

Question 3

What is mitosis

Answer 3

When one cell divides into two genetically identical daughter cells.

Question 4

What is PMATC

Answer 4

Stages 
Interphase
Prophase 
Metaphase 
Anaphase 
Telophase
Cytokinesis

Question 5

What is prophase

Answer 5

The membrane of the nucleus breaks down and spindle fibres start to form

Question 6

What is metaphase

Answer 6

Spindle fibres fully form and chromosomes line up across the middle of the cell

Question 7

What is anaphase

Answer 7

Chromosomes copies separate and move to each end of the cell

Question 8

What is telophase

Answer 8

A new membrane forms around each set of chromosomes to for two nuclei

Question 9

What is cytokinesis

Answer 9

The two new cells fully separate

Question 10

What is cancer

Answer 10

When mitosis happens out of control forming large lumps of cells called Tumours

Question 11

Growth

Answer 11

Increase in size due to increased numbers of cells

Question 12

Percentile

Answer 12

A measure of the growth of a child that compares them to other children of the same age

Question 13

90th percentile

Answer 13

A child is taller than 90% of children of the same age

Question 14

50th percentile

Answer 14

Average for height/mass for the age

Question 15

Percentile graphs

Answer 15

Graphs showing how height/mass change with age with different lines for each percentile

Question 16

Cell differentiation

Answer 16

When a cell divides by mitosis to produce two different types of cell

Question 17

Specialised cell

Answer 17

A cell special features designed for a specific job

Question 18

Importance of differentiation in animals

Answer 18

To produce all the different types of cell the body needs such as red blood cells fat cells nerve cells and muscle cells

Question 19

Plant growth

Answer 19

Cell division creates more cells elongation makes these cells get bigger

Question 20

Meristems

Answer 20

Areas just behind the tips of roots and shoots where cell division and differentiation happens

Question 21

Importance of differentiation in plants

Answer 21

To produce all the different types of cell a plant needs such as root hair cells and xylem cells

Question 22

Calculating percentage changes

Answer 22

% change = (final value - starting value ) / starting value x 100

Question 23

Stem cell

Answer 23

A cell that can differentiate when it divides, to produce two different cells

Question 24

Embryonic stem cell

Answer 24

A stem that can become any kind of cell

Found in developing embryos

Question 25

Adult stem cell

Answer 25

A stem cell that can only become w few types of cell | Found in animals after birth

Question 26

Stems cells in medicine

Answer 26

It’s is hoped they can be used to replace damaged cells in diseases like type 1 diabetes or leukaemia, or to grow new organs for transplant

Question 27

Problems with stem cells

Answer 27

They may potentially cause cancer stem cells can only be used in the person they have come from

Question 28

Nervous system

Answer 28

All the nerves in your body working together to gather information make decisions and control responses

Question 29

Central nervous system

Answer 29

The brain and spinal cord - makes decisions

Question 30

Peripheral nervous system

Answer 30

All your other nerves gathers information from your sense and carries messages from the CNS to your muscles

Question 31

Neurone

Answer 31

A nerve cell

Question 32

Impulse

Answer 32

Electrical message carries by a neutron

Question 33

Cell body

Answer 33

The central part of a nerve cell containing its nucleus

Question 34

Dendron and axon

Answer 34

The long parts of a nerve cell carrying out impulses towards the cell body and away form it

Question 35

Myelin sheath

Answer 35

A fatty layer around the axon and dendron that insulates it to prevent the impulse from escaping and speeds the impulse up

Question 36

Neurotransmission

Answer 36

The travelling of an impulse along a neuron and into another

Question 37

dendrites

Answer 37

branches at the beginning of a dendron that connect to receptor cells or another neuron

Question 38

axon terminals

Answer 38

branches at the end of an axon that connect to a muscle or another neuron

Question 39

synapse

Answer 39

small gap between two neurons where the axon terminals of one meet the dendrites of another

Question 40

neurontransmitter

Answer 40

chemicals released by axon terminals that diffuse across the synapse to trigger a new impulse the dendrite of another neuron

Question 41

sensory neuron

Answer 41

nerve cell that carries impulses from sense organs to the CNS has a long dendron and a long axon

Question 42

relay neuron

Answer 42

nerve cell in the CNS that makes decisions. dendrites join onto cell body short axon

Question 43

motor neuron

Answer 43

nerve cell that carries impulses from the CNS to muscles dendrites join onto cell body long axon

Question 44

stimulus

Answer 44

a piece of information detected by the nervous system

Question 45

receptor

Answer 45

cells that detect a stimulus

Question 46

response

Answer 46

the action that the produces the response , often a muscle

Question 47

effector

Answer 47

the body part that produces the response , often a muscle

Question 48

voluntary movement

Answer 48

a stimulus is detected by a receptor , causing an impulse to be carried by a sensory neuron to the brain. replay neurons in the brain decide what to do and send another impulse down a motor neuron to the effector to cause a response

Question 49

reflexes

Answer 49

automatic responses that happen very quickly without conscious thought to keep the body safe

Question 50

reflex arc

Answer 50

movement is caused in the same way as for voluntary movement except the spinal cord makes the decision without needing the brain to think