B10

Question 1

What is Homestasis?

Answer 1

Maintaining optimal conditions for enzyme action and all cell functions.

Question 2

Internal conditions that are controlled?

Answer 2

Blood glucose concentration
Body Temperature
Water levels

Question 3

Receptors?

Answer 3

Cells that detect stimuli (changes in the environment)

Question 4

Coordination centres?

Answer 4

Areas that receive and process information from the receptors.
Brain, Spinal Cord, Pancreas

Question 5

Effectors?

Answer 5

Muscles or glands that bring about a response to restore optimal levels.

Question 6

Regulation script:

Answer 6

• Stimulus
• Receptor-sends electrical impulse
• Sensory Neurone
• Coordinator
• Relay Neurone: synapse-chemical diffuses
• Motor Neurone
• Effector-eg. muscle contracts

Question 7

Reflex Action?

Answer 7

Rapid
Automatic
Unconscious part of the brain

Question 8

Brain:

Answer 8

Cerebral cortex= memory, speech, hearing, personality
Cerebellum=coordination & movement
Medulla=Unconscious activities like breathing & heart rate

Question 9

Investigating the Brain:

Answer 9

MRI Scanning
Studying patients with brain damage
Electrically stimulating different parts of the brain

Question 10

Difficulties with the Brain:

Answer 10

complexity

delicacy

Question 11

Reaction time method:

Answer 11

1) Student A sits with elbow resting on the edge of the table
2) Student B holds ruler with the bottom level with student A’s thumb
3) Student B drops ruler
4) Student A catches ruler and measures the distance
5) Repeat steps 1-4

Question 12

Control Variable:

Answer 12

Same ruler
Same arm grabbing ruler
Ruler always level with the thumb
Same person

Question 13

Improve accuracy:

Answer 13

Use a computer to measure reaction times

Question 14

The Eye:

Answer 14

Retina: contains receptors that detect light intensity and colour
Cornea: refraction of light into retina
Sclera: Tough & White- Protection
Lens: changes shape to focus on near/far objects
Ciliary muscles: contract/relax
Suspensory ligaments: loosen/tighten
Pupil: changes size to allow different amounts of light
Iris: contract/ relax controlling size of pupil

Question 15

Accommodation:

Answer 15

NEAR objects= ciliary muscles CONTRACT
suspensory ligaments LOOSEN
lens THICKEN, refracts light STRONGLY
FAR objects= ciliary muscles RELAX
suspensory ligaments TIGHTEN
lens THINNER, refracts light SLIGHTLY

Question 16

Accommodation acronyms:

Answer 16

NEAR: CONSTANTLY LETTING THINGS STREAM
Contract Loosen Thicken Strongly
FAR: REALLY TIGHTEN THOSE STRINGS
Relax Tighten Thinner Slightly

Question 17

Myopia( SHORT SIGHTEDNESS)

Answer 17

• eyeball too ELONGATED & cornea too CURVED

- glasses= Concave lens, light rays diverged, more refraction

Question 18

Myopia acronyms:

Answer 18

EMO CURTAINS CREATE DARKNESS

Elongated Curved Concave Diverged

Question 19

Hyperopia(LONG SIGHTEDNESS)

Answer 19

• ciliary muscles WEAKEN lens not round enough

- glasses=Convex lens, light rays converged and less refraction

Question 20

Hyperopia acronyms:

Answer 20

WEMBLEY’S NOT ROARING ‘CAUSE OF COVID

Weakened Not Round Convex Converged