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3a) Life Processes Flashcards

0
Q

What type of molecules can’t get through the membrane and what can?

A

Small molecules can - water

Big molecules can’t - sucrose

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1
Q

What is osmosis?

A

Net movement of water molecules across a partially permeable membrane from a region of high water concentration to low water concentration

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2
Q

How are exchange surfaces adapted to maximise effectiveness?

A

Thin - short distance diffuse across
Large surface area - quicker diffusion
Lots of blood vessels - quick exchange for blood

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3
Q

What are stomata?

A

Holes in the structure of leaves which allow oxygen and water vapour to diffuse out and carbon dioxide to diffuse in

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4
Q

What is the size of the stomata controlled by?

A

Guard cells

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5
Q

What is the thorax?

A

Upper part of your body (separated from the abdomen by the diaphragm)

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6
Q

What is the adomen?

A

Lower part of your body (separated from the thorax by the diaphragm)

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7
Q

What is the trachea?

A

Windpipe

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8
Q

What is the oesophagus?

A

Food pipe

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9
Q

What are bronchi?

A

Two tubes that the trachea splits up into (each one called a bronchus)

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10
Q

What are bronchioles?

A

Smaller tubes that the bronchi split up into

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11
Q

What are alveoli?

A

Millions of tiny air sacs in the lungs where gas exchange takes place

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12
Q

What happens when you breathe in?

A 
Intercostal musicales contract
Diaphragm contracts
Thorax volume increases
Pressure is decreased
Air is drawn in
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13
Q

What happens when you breathe out?

A 
Intercostal muscles relax
Diaphragm relaxes
Thorax volume decreases
Pressure is increased
Air is forced out
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14
Q

How is the leaf adapted for gas diffusion?

A

Flattened shape - increased surface area
Walls of cells have air spaces
Covered in stomata

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15
Q

How are alveoli adapted to maximise gas diffusion?

A

Enormous surface area
Moist lining
Very thin walls
Good blood supply

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16
Q

What are villi?

A

Millions of tiny little projections that cover the small intestine that help absorb digested food

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17
Q

How are villi adapted for diffusion and active transport?

A

Single layer of cells on surface - thinner

Very good blood supply - quicker absorption

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18
Q

What is active transport?

A

When substances are absorbed Against a concentration gradient

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19
Q

How are root hairs adapted for active transport?

A

Root hair cells have long hairs on surface of roots - bigger surface area

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20
Q

Why do humans need active transport?

A

Allows nutrients to be taken in from the blood against a concentration gradient
Low in gut - high in blood

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21
Q

What 2 types of vessels to plants have for transport?

A

Phloem tubes

Xylem tubes

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22
Q

Describe Phloem tubes

A 
Transport food substances (dissolved sugars)
To storage organs and growing regions
In both directions
Made of columns of living cells
Small holes at ends
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23
Q

Describe Xylem tubes

A 
Take water up - only one direction
Made of dead cells joined together
No end walls between cells
Hole down middle
Carry water and minerals from roots
To stems and leaves
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24
What is transpiration?
Loss of water from a plant Caused by evaporation and diffusion from inside leaves Water lost through stomata
25
Why is the transpiration system constant?
``` Water lost through stomata Water shortage More water drawn up from xylem vessels to replace it More water drawn form roots Water lost from stomata again ```
26
What does the double circulatory system transport?
Food and oxygen to all cells | Waste materials
27
Explain how the double circulatory system works?
Deoxygenated blood into right atrium of heart Pumped out of right ventricle to lungs for oxygen Becomes oxygenated and travels back into left atrium Pumped out of left ventricle Once oxygen used, cycle repeats as blood is deoxygenated again
28
What is the heart and what does it do?
Pumping organ that keeps the blood flowing around the body
29
What is the function of valves in the heart?
Push blood in right direction (upwards) | Prevent flowing backwards
30
Explain how the heart uses it's four chambers
Blood flows into right and left atrium from vena cava and pulmonary vein Atria contract pushing blood into the right and left ventricles Ventricles contact pushing blood into pulmonary artery and aorta Valves make sure blood flows up Blood exits heart into arteries
31
What are the three types of blood vessels?
Arteries - blood away from heart Capillaries - exchange if materials at tissues Veins - blood back into heart
32
Describe how arteries are adapted for their function
Strong, elastic walls - high pressure Thick walls compared to lumen Thick layers of muscle - strong Elastic fibres - stretchy and springy
33
Describe how capillaries are adapted for their function
Permeable walls - diffusion Usually walls only one cell thick - short diffusion distance Carry blood really close to cells - substances can be exchanged
34
Describe how veins are adapted for their function
Thinner walls - low pressure Bigger lumen - helps blood flow despite low pressure Valves - keep blood flowing in right direction
35
What is blood?
Tissue | Acts as a huge transport system
36
What 4 main things does the blood have?
Red blood cells - carry oxygen White blood cells - defends against diseases Platelets - help blood clot at wound Plasma - carries substances
37
How are red blood cells adapted for their function?
Concave doughnut shape - large surface area - absorb oxygen No nucleus - more rooms for oxygen Red pigment called haemoglobin
38
How are white blood cells adapted for their function?
Can change shape - engulf unwanted microorganisms Produce antibodies - fight pathogens Produce antitoxins - neutralise or counteract toxins Nucleus
39
What are platelets designed to do?
``` Small fragments of dead cells Help blood clot at wound Stops microorganisms getting in Stops blood pouring out Have a nucleus ```
40
What is coronary heart disease?
When arteries get blocked by fatty deposits | arteries become narrow and blood flow is restricted
41
What are stents and what do they do?
Tubes inserted inside arteries | Ensure arteries stay open by squashing the fatty deposit and blood can pass through
42
What are the advantages and disadvantages of an artificial heart?
``` Not rejected - not living tissue so body doesn't respond same way Parts can be replaced Bleeding, blood clots and infection Don't work as well as natural ones Parts of the heart could wear out Electric motor could fail Needs drugs to thin blood ```
43
What is homeostasis?
Maintenance of a constant internal environment or unchanging balance
44
What things does homeostasis need to control?
``` At right level: - Temperature - Water content - Ion content - Blood sugar level To be removed: - Carbon dioxide - Urea ```
45
Why does body temperature need to be maintained?
Enzymes work best at the optimum temperature - 37 degrees Celsius in humans
46
How does your body respond when your too hot?
Hair erector muscle relaxes - hairs lie flat on skin Sweat gland produce sweat - evaporates removing heat Vasodilation - blood flow close to skin surface increases - easier for heat to transfer to environment
47
How does your body respond when your too cold?
Hairs erect - hairs stand up and trap insulating layer of heat on skin No sweat produced Vasoconstriction - blood flow constricts to close off skins blood supply - harder for heat to transfer Shiver - muscles contract which needs respiration, releasing energy to warm up body
48
What 3 things do the kidneys do?
Remove urea - filtered out of blood Adjust ion content - excess ions removed from blood Adjust water content - excreted by kidneys in urine
49
What is urea?
Waste product produced from the reaction to convert any excess amino acids into fats and carbohydrates
50
What can sports drinks replace?
Water and ions lost in sweat | Sugar used up by muscles during exercise
51
What are nephrons?
Filtration units in the kidneys
52
Explain the process of ultrafiltration
High pressure squeezes out water, urea, ions and sugar out of blood Membranes between Normans capsule and blood vessels act like filters so big molecules like proteins remain in the blood
53
Explain the process of reabsorption
Useful substances re absorbed back into blood along nephron All sugar re absorbed through active transport Sufficient ions reabsorbed trough active transport, excess ions aren't Sufficient water reabsorbed
54
What happens as remaining substances continue our of the nephron?
Continue to ureter as urine Stored in bladder temporarily Excreted out of the body
55
What are the two main treatments of kidney failure?
Dialysis - machine filters blood to maintain concentration of substances Transplant
56
What are the advantages and disadvantages of dialysis?
Only waste substances and excess ions can diffuse across barrier Session 3 times a week, 3-4 hours May cause blood clots or infections
57
What are the advantages and disadvantages of Kidney transplant?
Could be rejected by immune system Only cure for kidney failure Need donor with similar tissue type Drug treatment to suppress immune system
58
What two hormones does the pancreas use to control blood sugar level?
Insulin - when level is too high | Glucagon - when level is too low
59
What does insulin do to reduce blood sugar levels?
Converts glucose into glycogen stored in liver | Reduces amount of glucose in blood
60
What does glucagon do to reduce blood sugar levels?
Converts glycogen stored in liver back into glucose | Increased amount of glucose in blood
61
What is type 1 diabetes?
Condition where pancreas produced little or no insulin | No control when blood sugar level too high
62
How can type 1 diabetes be avoided?
Avoiding foods rich in carbohydrates Exercising Injecting insulin at mealtimes Pancreas transplant

Biology (6 decks)

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