B4 - Organising plants and animals

Question 1

Blood components

Answer 1

• RBCs
• WBCs
• Platelets
• Plasma

Question 2

Plasma components

Answer 2

• Water
• Proteins (enxymes, antibodies)
• Carbon dioxide
• Sugars/ amino acids/ fatty acids + glycerol
• Mineral ions
• Hormones
• Urea

Question 3

How does blood clot

Answer 3

Cell fragments in presence of calcium ions and tamaged tissue cause fibrin protein strands to create a mesh which traps RBCs. This forms a clot.

Question 4

Scabs

Answer 4

Dried out clots.
Prevents entry of pathogens and allows tissue beneath to repair.

Question 5

Condition where blood doesn’t clot

Answer 5

haemophilia

Question 6

Vein structure

Answer 6

Tough fibrous outer layer
Thin muscle and elastic fibre middle wall.
Single celled lining layer inside
Wide lumen (gap) for blood flow
Contains valves

Question 7

Arteries structure

Answer 7

Tough fibrous outer layer
Much thicker muscle and elastic fibre middle layer than veins
Same thin single celled lining layer inside as veins
Narrow lumen (gap) for blood flow

Question 8

Vein function

Answer 8

Transport blood towards heart
Low pressure, non pulsing flow
Valves prevent backflow - especially in legs
If cut, will spill out at steady speed
Purpely colour (Not in pulmonary circulation)

Question 9

Artery function

Answer 9

Transport blood away from heart
High pressure, pulsing flow
If cut, will spurt out
Bright red (Not in pulmonary circulation)

Question 10

Capillary structure

Answer 10

Single cell thick wall
Very narrow lumen - RBCs one at a time
Very fragile
Large SA

Question 11

Capillary function

Answer 11

Leak water + soluble material into surrounding cells
Material from cells can also enter capillaries

Question 12

Blood vessels of the heart

Answer 12

The vena cava
The main vein that carries deoxygenated blood from the body to the heart

The pulmonary artery
Carries deoxygenated blood from the heart to the lungs

The pulmonary vein
Carries oxygenated blood from the lungs to the heart

The aorta
The main artery that carries oxygenated blood from the heart to the body

Question 13

Arterial flow vs venous flow

Answer 13

Aorta - arteries - arterials - capillaries

Vena cava - veins - venules - caplilaries

Question 14

Double circulation

Answer 14

All mammals have it
One loop for lungs (pulmonary)
Another loop for everything else (systemic)
OXygen collection and CO2 excretion highly efficient
Mammals and birds respire rapidly and maintain high body temperatures

Question 15

Heart structure and how it contracts

Answer 15

Cardiac muscle
Nervous tissue
Needs oxygen and glucose to respire
Doesn’t fatigue
Electrical impulses cause contraction
Regulates speed + volume of contracting chambers

Question 16

Cardiac output calc

Answer 16

Cardiac output (dm3*min-1) = stroke volume (dm3) * cardiac frequency (beats per min-1)

Question 17

Heart structure

Answer 17

Left and right switched. Atrium at top since A comes before V.
Left ventricle has thicker muscle to generate more force to drive blood.
See on paper since brainscape is a money hogging scheme

Question 18

Heart flow pattern

Answer 18

Vena cava -> RA -(valve)-> RV -> Pulmonary artery -> lungs -> Pulmonary vein -> LA -> LV -> aorta -> rest of body -> repeat

Question 19

Pacemaker

Answer 19

Wall of right atrium. Made of nerve cells + initiates each contraction. Regulates speed of heart

Question 20

Conorary heart disease

Answer 20

Coronary arteries becoming blocked by fatty deposits

Question 21

Cardiovascular diseases risks

Answer 21

Decreased supply of essential minerals
Oxygen deficiency - poorly oxygenated RBCs
O2 build up in tissues
Low blood pressure - platelets, water, hormones etc. not delivered
Urea not taken to kidneys + not made into urine

Question 22

CV disease risk factors

Answer 22

High saturated fats
Lack of cardio excercise
Smoking
Overweight/obese
High salt diet
Male
Old

Question 23

Thrombosis

Answer 23

Clots form in blood vessels when not supposed to. Tissues beyond clot starved of O2 and glucose - die.

Question 24

Stent

Answer 24

Small tube fitted via groin with anaesthetic to increase diameter of arteries. Some release anti-clotting drugs.

Question 25

Transplants for CVD

Answer 25

Healthy donor heart (or heart and lungs) into the patient. A mechanical artificial heart can be fitted which they are waiting for a donor heart, or to allow their own heart to rest and recover. Donor dead? Animals? Rejection?

Question 26

Statin

Answer 26

Drugs lower blood cholesterol - reduces atheroma (fatty material that clogs arteries). Slow the rate of fatty deposits forming in the arteries

Question 27

By-pass surgery

Answer 27

New pieces of artery sewn into vessel to bypass narrowed section.

Question 28

Heart rhythm problem

Answer 28

Artificial pacemaker Drugs to stimulate/ control heart rhythm

Question 29

Heart valve problems

Answer 29

Mechanical, artificial, pig/cattle replacement

Question 30

Lungs organisation

Answer 30

Trachea -> bronchus -> bronchiole -> alveolus

Question 31

Lung adaptations

Answer 31

Large surface area to allow faster diffusion of gases across the surface 1 cell thick walls to ensure diffusion distances remain short Good blood supply (dense capillary network) to maintain a high concentration gradient so diffusion occurs faster

Question 32

Inhalation

Answer 32

Intercostal muscles move chest up and out Diaphragm contracts down Volume increase Pressure decreases Air moves from outside into lungs

Question 33

Exhalation

Answer 33

Intercostal muscles move chest down and in Diaphragm relaxes Volume decreases Pressure increases Air moves out of lungs into atmosphere

Question 34

Leaf structure top to bottom

Answer 34

Waxy cuticle Protective layer on top of the leaf, prevents water from evaporating Upper epidermis Thin and transparent to allow light to enter palisade mesophyll layer underneath it Palisade mesophyll Column shaped cells tightly packed with chloroplasts to absorb more light, maximising photosynthesis Spongy mesophyll Contains internal air spaces that increases the surface area to volume ratio for the diffusion of gases (mainly carbon dioxide) Lower epidermis Contains guard cells and stomata Guard cells Absorbs and loses water to open and close the stomata to allow carbon dioxide to diffuse in, oxygen to diffuse out Stomata Where gas exchange takes place Opens during the day, closes during the night, evaporation of water also takes places from here In most plants, found in much greater concentration on the underside of the leaf to reduce water loss

Question 35

Where is merristem

Answer 35

Tips of the growing regions of plants and can differentiate into different types of plant cell.

Question 36

Translocation

Answer 36

Transport of dissolved food (e.g. sucrose, a sugar) from the leaves to other parts of the plant. It happens in the phloem which is adapted to carry out this function.

Question 37

Xylem function

Answer 37

Transports water and minerals from the roots to the leaves. It is adapted to carry out this function and has walls strengthened by a waterproof substance called lignin.

Question 38

Transpiration

Answer 38

Loss of water from plants (usually via stomata) due to evaporation

Question 39

Air movement affect on transpiration

Answer 39

High air movement = high transpiration. Removes water vapor from surrounding air and creates a conc gradient

Question 40

Humidity affect on transpiration

Answer 40

High humidity = low transpiration Low conc gradient

Question 41

light intensity affect on transpiration

Answer 41

High light intensity = high transpiration Guard cells become turgid in light and stomata open - water is lost

Question 42

Temperature affect on transpiration

Answer 42

High temperature = high transpiration Particles have more kinetic energy and a higher tendency to evaporate from mesophyll

Question 43

What is used to investigate the rate of water uptake by a plant

Answer 43

Potometer