Topic 2 - Cells and Control

Question 1

What do our chromosomes contain?

Answer 1

Our genetic information - what makes us like we are

Question 2

What is the cell cycle?

Answer 2

Division of cells to produce new cells

Question 3

What is interphase in the cell cycle?

Answer 3

• Amount of subcellular structures increases

- DNA is copied, forming X chromosomes, with the two halves being identical

Question 4

What is mitosis?

Answer 4

The division of cells to form 2 identical daughter diploid cells

Question 5

What are the 4 stages of mitosis?

Answer 5

Prophase - Chromosomes condense, nuclear membrane breaks
Metaphase - Chromosomes line up at the centre of the cell
Anaphase - Cell fibres pull chromosomes apart
Telophase - Membranes form around the sets of chromosomes

Question 6

What is cytokinesis?

Answer 6

The cytoplasm and cell membranes divide into two separate cells

Question 7

What is cancer?

Answer 7

The uncontrollable division of cells

Question 8

What can percentile graphs be used for?

Answer 8

Monitoring growth - they show weight compared to age, and where your child fits on that graph

Question 9

What are stem cells?

Answer 9

Undifferentiated cells that can become any specialised cell

Question 10

Where are stem cells usually found?

Answer 10

In human embryos, as the cells have only divided, and have not yet become specific to one purpose

Question 11

Where can stem cells be found in fully developed adults?

Answer 11

Bone marrow

Question 12

What are stem cells mainly used for?

Answer 12

Medicine - Stem cells can become any type of cell, and so can fix diseases that are caused by poorly formed cells

Question 13

What is the CNS?

Answer 13

Central Nervous System

Question 14

What two components make up the CNS?

Answer 14

• Brain

- Spinal Cord

Question 15

Name 3 parts of the brain, and their functions:

Answer 15

• Cerebrum: Divided into two hemispheres, right side controls muscles on the left side and vice versa. Different parts are responsible for different things such as movement, intelligence, memory, etc.
• Cerebellum: Muscle coordination
• Medulla oblongata: Control unconscious activities such as breathing and your heart rate

Question 16

What are the two types of brain scans?

Answer 16

• CT Scan: Produces an image of the brain

- PET Scan: Uses radioactive materials to show what parts of the brain are active

Question 17

What does the CNS coordinate?

Answer 17

Responses

Question 18

What are three types of neurones?

Answer 18

• Sensory Neurone
• Motor Neurone
• Relay Neurone

Question 19

How do neurones transmit information?

Answer 19

Through electrical impulses

Question 20

What do synapses do?

Answer 20

Connect neurones

Question 21

What is a reflex?

Answer 21

Automatic, rapid responses to stimuli

Question 22

Where does information move to and from ina reflex?

Answer 22

From a receptor to an effector

Question 23

What are the different parts of the eye, and what are their functions?

Answer 23

• Cornea: Refracts light into the eye
• Iris: Controls how much light enters the eye
• Lens: Focuses light onto the retina
• Retina: Detects light at the back of the eye
• Rods: Sensitive to dim light
• Cones: Sensitive to different colours
• Optic Nerve: Carries electrical impulses to the brain

Question 24

What causes colour blindness?

Answer 24

Red or green cones that do not work properly

Question 25

What is a cataract?

Answer 25

A cloudy patch on the lens, which stops light entering the eye normally

Question 26

What is short-sightedness?

Answer 26

Inability to focus on distant objects

Question 27

What is long-sightedness?

Answer 27

Inability to focus on close objects