Organisation and Transport in Plants + Animals

Question 1

What is blood

Answer 1

A tissue consisting of plasma, platelets, red blood cells and white blood cells

Question 2

Plasma

Answer 2

Yellow liquid that transports all blood cells and other substances (glucose, antibodies, hormones) around the body
e.g Carbon dioxide to the lungs, urea to the kidneys from the liver, small soluble products of digestion from the small intestine to your cells

Question 3

Red blood cells

Answer 3

Contains haemoglobin which binds to oxygen to transport it from lungs to tissues and cells, which need it for respiration.

Question 4

oxygen and haemoglobin word equation

Answer 4

oxygen + haemoglobin <-> oxyhaemoglobin (reversible)

Question 5

White blood cells

Answer 5

Bigger than red blood cells, wbc are part of the body’s defence system against harmful microorganisms
● Some produce antibodies
● Some form antitoxins
● Some ingest and digest bacteria and viruses

Question 6

Platelets

Answer 6

Small fragments of cells which recognise damaged blood vessels and trigger blood clotting to prevent too much bleeding

Question 7

How are red blood cells adapted to their function

Answer 7

● Biconcave disc shape – increased sa:v ratio which increases diffusion of oxygen
● Very small, can fit through tiny capillaries
● No nucleus – more space for haemoglobin.
● Packed with haemoglobin

Question 8

Arteries

Answer 8

Take blood from heart to organs
Have thick walls made from muscle and elastic fibres
Small lumen

Question 9

Veins

Answer 9

Take blood from organs to heart
Thinner walls and valves to prevent backflow
Large lumen

Question 10

Capillaries

Answer 10

Allow substances needed by cells to pass out of the blood
Allow substances produced by the cells to pass into the blood
Allow exchange of oxygen, co2, hormones etc
Narrow, very thin walls a single cell layer thick, narrow lumen
Diffusion distances are short

Question 11

Why is a transport system needed

Answer 11

To circulate chemicals around the body - oxygen and glucose are needed for respiration by every cell and cells need to get rid of waste products e.g carbon dioxide and urea

Question 12

Double circulation system process

Answer 12

Oxygenated blood is pumped by the heart to the rest of the body
Oxygen leaves the blood in the body and the blood returns to the heart
Deoxygenated blood is pumped from the heart to the lungs
At the lungs, the blood receives oxygen and is pumped back to the heart

Question 13

Pacemaker cells

Answer 13

Regulate natural resting heart rate, found in right atrium

Question 14

Coronary heart disease

Answer 14

Layers of fatty material build up in coronary arteries and narrow them, reducing blood flow to the heart
Reduces supply of oxygen to the heart muscle, resulting in pain, heart attacks, even death

Question 15

How do stents work

Answer 15

Small cut in thigh, tube carrying a balloon inserted
When in place, balloon will inflate to expand the stent
Balloon deflates, stent is in place, artery is widened

Question 16

Stents pros and cons

Answer 16

Increases blood flow
Cheap
No general anaesthetic
Patients will recover well
Will not work on very blocked arteries

Question 17

How do statins work

Answer 17

Prescribed tablets that reduce blood cholesterol levels, thin blood

Question 18

Statins pros and cons

Answer 18

Slows down the rate of fatty material deposit
Non invasive
No surgery risk - no concern
Have to take for life
Side effects
Patients may forget/od

Question 19

How does a bypass operation work

Answer 19

Vein is taken from thigh and attached to the heart
Vein placed underneath the blockage, making an alternative route for blood flow

Question 20

Pros and cons of bypass operation

Answer 20

Effective if the blockage is severe
General anaesthetic involved (risky)
Expensive

Question 21

Leaky valves

Answer 21

Over time heart valves can become leaky or stiff, making the heart less efficient - can result in death if not treated

Question 22

Mechanical valves

Answer 22

Made of metal - titanium (blood does not react to) and polymer
Lasts a long time in the body
Requires open heart surgery
You need to take anti-clotting drugs for the rest of your life to prevent clotting around the artificial valve

Question 23

Biological valve

Answer 23

Comes from pig or cattle hearts and sometimes human donors
Pigs/cattle have ethical and religious issues attached
Work extremely well, no need for medication
Need to take immunosupressant
Only last 12-15 years, need replacing

Question 24

Artificial pacemakers

Answer 24

Electrical device which corrects irregularities in the heart rate, implanted into the chest
Sends strong, regular electric signals to heart to stimulate it to beat properly

Question 25

Pacemaker cells stop working

Answer 25

Beats too slow - cells dont get enough oxygen Beats too fast - cannot pump blood properly

Question 26

Heart failure

Answer 26

Donor heart can be transplanted, but requires a donor heart to be available and many die waiting

Question 27

Artificial hearts

Answer 27

Can be used to keep patients alive while waiting for a heart transplant or to allow the heart to recover

Question 28

Respiratory system what goes on

Answer 28

Heart sends blood to lungs via pulmonary artery Air obtained by breathing reaches lungs through trachea Trachea divide in two tubes - bronchi Bronchi divide forming bronchioles, then tiny air sacs alveoli Alveoli - site of gas exchange Blood taken back to lungs through pulmonary vein

Question 29

Alveoli

Answer 29

MAke gas exchnage more efficient, well adapted: Rich supply of capillaries maintaining a concentration gradient Close to capillaries so short diffusion distances Spherical shape - large sa:v

Question 30

Inspiration (lol)

Answer 30

Diaphragm contracts, moves downwards Intercostal muscles contract, moving ribcage up and out Vloume of the thorax is increased Pressur in the chest decreases, is now lower than air pressure outside, so air is drawn into the lungs

Question 31

Expiration

Answer 31

Diaphragm muscle relaxes and moves upwards Intercostal muscles relax and ribcage falls down Volume of thorax is decoreased Pressur in the chest increases, is now greater than air pressure outside, so air is forced out of teh lungs

Question 32

Waxy cuticle

Answer 32

Stops water loss due to photosynthesis

Question 33

Epidermis

Answer 33

Covers the outer surfaces of the plant for protection

Question 34

Palisade layer

Answer 34

COntains lots of chloroplasts for photosynthesis

Question 35

Spongy mesophyll layer

Answer 35

Air spaces between cells allow gases to diffuse through the leaf

Question 36

Xylem vessels

Answer 36

Transports water and minerals up through the plant, from roots to leaves

Question 37

Phloem vesseks

Answer 37

Transports sugars made in photosynthesis from leaves through the rest of the plant

Question 38

Stomata

Answer 38

Allow diffusion of gases in/out of the leaf, can be open and closed by guard cells.

Question 39

What do leaves need to photosynthesise?

Answer 39

Large surface area to absorb light, many chloroplasts containing chloropyll, a supply of water and co2, a system for carrying away the products of photosynthesis to other parts of the plant

Question 40

Stomata conditions

Answer 40

Found in lower epidermis which is shaded and cooler; open during the day when carbon dioxide is needed for photosynthesis and excess oxygen can leave. AT night, stomata closes to prevent water vapour being lost when the plant can't photosynthesise, can also close when the plant loses more water than it can replace

Question 41

Translocation

Answer 41

the movement of dissplved sugars from the leaves to the rest of the plant; these sugars are needed for respiration to release energy and provide materials for growth

Question 42

Xylem vs phloem

Answer 42

Dead vs alive Lignin vs none No end plates vs some Water and mineral ions vs sugars and water Up only vs up and down

Question 43

Water and mineral ions obtained

Answer 43

Water absorbed into roots via osmosis, carried by vascular bundle to leaves where it is used for photosynthesis Mineral ions are obtained from the soil by plant roots via active transport and transported by xylem upwards to wherever needed

Question 44

Root hair cells adaptions

Answer 44

Large Sa:V ratio to increase rate of osmosis Contains lots of mitochondria which release energy to provide energy needed for active transport

Question 45

Transpiration

Answer 45

Evaporation/loss of water in the leaves

Question 46

Process of transpiration

Answer 46

Water diffuses out of the stomata, replaced by other water through osmosis, this has a knock on effect through whole plant therefore water constantly enters the roots and is drawn up the xylem

Question 47

Rate of transpiration measure

Answer 47

Can be measured from a cut shoot by estimating the rate at which the shoot takes up water (only an estimate as some water is used in the leaf)

Question 48

Transpiration stream

Answer 48

Movement of water through the plant from the roots up to the leaves - driven by loss of water vapour from the leaves

Question 49

Temperature effect on transpiration

Answer 49

Higher temp = higher rate as more energy is transferred to the water to allow it to evaporate quicker

Question 50

Air flow rate effect on transpiration

Answer 50

Faster air flow = higher rate as wind will blow away water vapour allowing more to evaporate, if air is still moist air stays close to stomata so the concentration gradient is low

Question 51

Light effect on transpiration

Answer 51

Lighter = faster rate as stomata will open so more water can escape

Question 52

Humidity effect on transpiration

Answer 52

Less humidity = faster rate as air contains less water vapour so the concentration gradient for diffusion is higher