Movement of Substances, Circulatory System, Hormones, Homeostasis, Reproduction

Question 1

Definition of diffusion

Answer 1

The movement of particles from an area of high concentration to an area of low concentration until equilibrium.

Question 2

Definition of osmosis

Answer 2

The movement of particles from an area of high water potential to an area of low water potential through a partially permeable membrane.

Question 3

Active transport definition.

Answer 3

The movement of particles against the concentration gradient requiring energy.

Question 4

What effect does increasing SA: VOL ratio have on rate of movement?

Answer 4

Increases

Question 5

What effect does increasing distance have on rate of movement?

Answer 5

Decreases rate.

Question 6

What effect does increasing temperature have on the rate of movement?

Answer 6

Increases the rate.

Question 7

What effect does increasing the concentration gradient have on rate of movement for diffusion and osmosis?

Answer 7

Increases rate of movement.

Question 8

What effect does increasing concentration gradient have on rate of active transport?

Answer 8

Decreases rate.

Question 9

4 components of blood.

Answer 9

1. Red blood cells
2. White blood cells
3. Plasma
4. Platelets

Question 10

Function of red blood cells

Answer 10

To transport oxygen around the body using haemoglobin

Question 11

Adaptations of red blood cells

Answer 11

Biconcave
No nucleus
Haemoglobin

Question 12

Function of phagocytes

Answer 12

Phagocytosis (enclosing, ingesting and digesting pathogens with enzymes)

Question 13

Function of lymphocytes

Answer 13

To produce and release antibodies

Question 14

Definition of antibodies.

Answer 14

Soluble proteins

Question 15

4 things that antibodies do:

Answer 15

Neutralise toxins produced by pathogens
Cause bacteria to burst open and die
Label the pathogen so it can be found by phagocytes
Stick pathogens together in clumps

Question 16

Function of plasma

Answer 16

To transport:
Hormones
Nutrients
Urea
CO2
Heat energy

Question 17

Function of platelets

Answer 17

Involved in blood clotting to prevent loss of blood (specifically erythrocytes) and infections.

Question 18

Equation for how platelets create a protein mesh.

Answer 18

Fibrinogen (soluble plasma protein) —> fibrin (insoluble)

Question 19

Definition of a pathogen

Answer 19

A disease causing cell. Can be fungi, bacteria, protoctist and viruses.

Question 20

Explain how vaccination reduces danger of a specific pathogen.

Answer 20

• injects inactive pathogen cells into the bloodstream.
• allows lymphocytes to create the specific antibodies needed to combat the pathogen
• once the pathogens have been eliminated, a few lymphocytes remain in the bloodstream as memory cells.
• if the pathogen were to return, the memory cells would be able to produce antibodies sooner, faster and in greater quantity.

Question 21

3 differences between structures of artistries and veins

Answer 21

1. Arteries have thicker, more elastic walls
2. Arteries do not have valves
3. Arteries have smaller lumens.

Question 22

Function of capillaries.

Answer 22

To take oxygen and nutrients to cells in organs and muscles as well as to take waste products away.

Question 23

Adaptations of capillaries.

Answer 23

• small

- one cell thick walls

Question 24

Explain why heart rate increases during exercise

Answer 24

• an increased amount of energy is needed for muscles to contract
• more blood carrying oxygen and glucose needs to be pumped by the heart to the muscles for aerobic respiration
• heart rate increases

Question 25

Explain what happens when someone has Coronary Heart Disease.

Answer 25

The coronary artery, which supplies blood to the heart for aerobic respiration becomes blocked (by a buildup of fat) and so the heart may run short of O2 and not be able to contract.

Question 26

Factors to decrease risk of CHD:

Answer 26

• regular exercise
• eating fewer fatty foods
• smoking (increases blood pressure)
• hereditary
• high cholesterol levels

Question 27

Definition of homeostasis

Answer 27

The maintenance of a constant/stable environment

Question 28

What three things does a coordinated response require?

Answer 28

Stimulus (the change in environment)
Receptor (the part of the body that detects the change)
Effector (the organ/cell/tissue that produces a response)

Question 29

3 things that happen when body is too hot

Answer 29

Sweating, cools down the skin.
Vasodilation, allows heat to radiate from blood to surroundings.
Hair erector muscles relax.

Question 30

3 things that happen when body is too cold.

Answer 30

Vasoconstriction, prevents heat from radiating to surroundings
Hair erector muscles contract, creating insulation layer
Muscles shiver, forcing body to produce (heat) energy

Question 31

Source, role and effect of ADH

Answer 31

Source: pituitary gland
Role: to maintain constant body water levels
Effect: prevents water from being excreted when body is dehydrated by making collecting duct more permeable so it can be reabsorbed

Question 32

Source, role and effect of FSH

Answer 32

Source: pituitary gland
Role: menstrual cycle
Effect: causes the maturation of an egg in the ovaries, stimulates production of oestrogen.

Question 33

Source, role and effect of LH

Answer 33

Source: pituitary gland
Role: menstrual cycle
Effect: inhibits production of oestrogen, causes an egg to be released by ovaries, stimulates production of progesterone.

Question 34

Source, role and effect of adrenaline

Answer 34

Source: adrenal gland
Role: to prepare body for fight/flight response,p
Effect: increases heart rate and breathing rate, initiates conversion of glycogen to glucose in the liver, blood is diverted from digesting system to muscles in the limbs

Question 35

Source, role and effect of insulin

Answer 35

Source: Pancreas
Role: to bring blood glucose levels back to normal
Effect: stimulates liver to convert glucose into glycogen, which is the storage form of glucose.

Question 36

Source, role and effect of testosterone

Answer 36

Source: testes
Role: to control the development of male secondary characteristics
Effect: stimulates sperm production

Question 37

Source, role and effect of progesterone

Answer 37

Source: ovaries
Role: menstrual cycle
Effect: maintains the uterus lining, inhibits production of LH

Question 38

Source, role and effect of oestrogen

Answer 38

Source: ovaries
Role: controls the development of female secondary sexual characteristics
Effect: inhibits production of FSH, causes the uterus lining to thicken and grow

Question 39

Describe the role of the placenta nun the nutrition of the developing embryo.

Answer 39

• allows substances to diffuse from the mother’s blood to the foetus and opposite
• mother —> foetus antibodies, water, amino acids, fatty acids, glycerol, glucose
• foetus —> mother carbon dioxide, urea.

Question 40

Role of the amniotic sac in protecting the embryo.

Answer 40

Protects the embryo by cushioning impacts

Contains amniotic fluid (made up mostly of foetal urine)