P1: Organisation Flashcards
(118 cards)
1
Q
Which cell structure in a leaf mesophyll cell is not found in a root hair cell?
A
Chloroplasts.
2
Q
Name the cells in a leaf that control the rate of water loss.
A
Guard cells.
3
Q
Describe the transport of water through a plant from the roots to the atmosphere.
A
Water is transported in xylem, then evaporates from leaves through the stomata.
4
Q
What is an organ?
A
A group of tissues that work together to form a specific function.
4
Q
How is the volume of water lost from the leaves controlled?
A
By the guard cells opening and closing the stomata.
5
Q
Which scientific term describes the movement of water when it is taken in by the roots, transported up the plant and lost from the leaves?
A
Transpiration stream.
6
Q
What is a tissue?
A
A group of cells that perform a similar function
7
Q
What is the heart’s function?
A
To pump blood around the body.
7
Q
What is the epidermis?
A
The outer layer of the plant.
8
Q
What is an organ system?
A
A group of organs working together.
9
Q
What is an organism made of?
A
Lots of organ systems all working together
10
Q
What is an enzyme?
A
A biological catalyst.
11
Q
What is an optimum level?
A
A particular level whereby the enzymes work best
11
Q
What do digestive enzymes do?
A
Help to break down large food molecules into smaller, soluble molecules.
12
Q
What causes an enzyme to denature?
A
If the temperature or pH is too high.
12
Q
What does amylase do?
A
Helps break down starch into simple sugars
13
Q
Explain the Lock and Key Theory.
A
1) Substrate collides with active site of enzyme and becomes attached. Active site has a complimentary shape to the substrate.
2) Enzyme catalyses breakdown of substrate
3) Products are released from the active site, enzyme molecule is unchanged and can be reused.
14
Q
What do proteases do?
A
Break down proteins into amino acids.
15
Q
What do lipases do?
A
Break down lipids into fatty acids and glycerol
16
Q
Where is amylase made?
A
The salivary glands, the pancreas and the small intestine.
17
Q
Where is protease made?
A
The pancreas, the stomach and the small intestine
17
Q
Where is lipase made?
A
The pancreas and the small intestine
18
Q
Where does amylase work?
A
Mouth and small intestine.
19
Q
Where does protease work?
A
Stomach and small intestine.
20
Where does Lipase work?
Small intestine.
21
Where is bile made?
The liver
22
What does the stomach produce that allows Protease to work effectively?
Hydrochloric acid, which allows the stomach to maintain a low pH.
23
Where is excess bile stored?
Gallbladder.
24
What does bile do?
-Emulsifies fats, breaking them down into small droplets.
-Neutralises the hydrochloric acid from the stomach.
25
State the order of the digestive system.
Mouth, Oesophagus, Stomach, Small Intestine (simultaneously the Liver, Gallbladder and Pancreas), Large Intestine, Rectum, Anus.
26
State the function of the mouth.
Chews and breaks down food. (Ingestion and digestion).
26
State the function of the stomach.
Holds food while it is mixed with enzymes, and breaks food down
27
State the function of the oesophagus.
Food is pushed through it to the stomach by a series of contractions called peristalsis
28
State the function of the liver.
Processes blood containing the nutrients absorbed from the small intestine, and produces bile.
29
State the function of the gallbladder.
Stores excess bile made in liver, and sprays food in the small intestine with bile.
29
State the function of the Pancreas.
Creates and releases digestive enzymes that are sent to the small intestine.
30
State the function of the small intestine.
Long muscular tube that is split into 3 sections. Breaks down food using enzymes.
31
State the function of the Large Intestine.
Processes waste and absorbs excess water.
31
State the function of the rectum
An 8 inch chamber that receives waste from the large intestine and stores it.
32
State the function of the Anus.
The last part of the digestive tract that releases stool. Composed of 2 sphincters.
33
State the 4 components of blood.
Plasma, Red blood cells, White blood cells, Platelets.
34
State the function of plasma.
Transports waste carbon dioxide to the lungs, carries urea from the liver to the kidneys for excretion. Carries small, soluble products of digestion from the small intestine to individual cells.
35
State the function of platelets.
Start the clotting process at the wound site.
36
State the function of the red blood cells.
Pick up oxygen from the lungs and carry it to the cells where it is needed. Packed with haemoglobin. No nucleus so that there is more room for oxygen.
37
State the function of white blood cells.
Body’s defence system against microorganisms. Form antibodies, antitoxins, engulf and digest bacteria and viruses. Bigger than red blood cells.
38
Describe and state the function of the arteries.
Carry blood away from the heart. No valves, thick layer of muscle with narrow space inside. Blood flows at high pressure.
39
Describe and state the function of the capillaries.
Carries blood close to every cell in the body. Connects veins and arteries. No valves, walls are one cell thick, tiny vessels. Low blood pressure and slow speed of blood flow to allow the exchange of materials.
40
What type of circulatory system does the human heart work in?
Double circulatory system.
41
How does the deoxygenated blood from the body enter the heart?
Through the vena cava.
42
How does deoxygenated blood leave the heart?
Through the pulmonary artery,
43
How does oxygenated blood enter the heart?
Through the pulmonary vein.
44
How does oxygenated blood leave the heart?
Through the aorta.
45
What prevents the backflow of blood?
Valves.
46
What are the two types of circulation in a double circulatory system?
Pulmonary and systemic.
47
What controls the natural resting heart rate?
A group of cells in the right atrium.
48
What can be used to fix an irregular heart beat?
An artificial pacemaker.
49
How do artificial pacemakers work?
Produce electrical pulses to make the heart beat.
49
What is coronary heart caused by?
An unhealthy diet.
50
What is coronary heart disease?
A common but serious condition where blood vessels supplying the heart are narrowed/blocked by a build-up of fatty substances in the blood vessels supplying the heart.
51
What can doctors do to treat coronary heart disease?
-Add stents (metal mesh) to open up arteries.
-Prescribe statins which slow down the rate at which fatty materials are deposited into coronary arteries.
51
What can coronary heart disease cause?
Pain, heart attacks or even death.
51
What can happen to heart valves overtime?
May start to leak, become stiff or not open fully.
52
What can doctors do to treat leaky valves?
-Operate and replace old valves with new ones.
Artificial ones are typically made of titanium and polymer.
Biological valves are taken from pigs, cattle or humans and only last around 12 years.
53
Describe the journey of the air from the environment to your lungs.
Environment, nasal cavity, trachea, bronchus, bronchioles, alveoli.
53
What is health?
The state of mental and physical well-being
54
Explain how alveoli are adapted for diffusion.
-Well ventilated, each alveolus is surrounded by capillaries to maintain a high concentration gradient
-Large surface area
-Moist
55
Why are individuals chosen at random for scientific studies?
To make the data representative of the whole population
55
What are tumours?
Unwanted balls of cells that grow in the body.
56
What type of disease is coronary heart disease?
Non-communicable.
57
What are pathogens?
Microorganisms that cause communicable diseases.
58
What are the two types of tumours?
Benign or malignant.
59
What is a benign tumour?
A tumour that is found in one place in the body and are normally contained within a membrane. These don’t invade other parts of the body
60
What is a malignant tumour?
Also known as a cancer, that invades nearby tissues and enters the bloodstream. Can form secondary tumours.
61
What increases the risk of skin cancer?
The longer you spend in the sun.
61
What increases the risk of lung cancer?
Smoking more.
61
What increases the risk of liver cancer?
Drinking more alcohol.
62
What unchangeable factor increases the risk of getting cancer?
Genetics
63
What is cholesterol?
A type of lipid. It is important for our health to keep cholesterol in the bloodstream at appropriate levels, other it can cause health problems like cardiovascular disease.
63
When is a heart transplant required?
When the heart fails.
64
Explain the structure of red blood cells.
-Packed with haemoglobin which allows them to hold oxygen
-No nucleus to allow more space for haemoglobin
-A concave shape to give them a larger surface area
-Small and flexible to fit through narrow capillaries
64
What are the problems with heart transplants? (3 reasons)
-Few donors are available
-Recovery time is long
-There is a risk of rejection by the body’s immune system.
65
How do white blood cells kill pathogens?
If they are a phagocyte, they surround the bacteria, engulf it and digest it. If they aren’t, they release antibodies and antitoxins to destroy them.
66
What are the two types of cells that transport substances around in plants?
Xylem and Phloem
67
What are the features of plant leaves? Also explain them.
-Large surface areas (for maximum absorption of light and carbon dioxide)
-Thin, flattened blade (So that water and gases have a limited distance to diffuse)
-Vascular tissue in the midrib and veins (To transport water and minerals to the leaf, to transport glucose to other parts of the plant)
-Air spaces between cells within the leaf. (For the diffusion of gases)
68
Which layer of the leaf absorbs light?
Palisade mesophyll layer
69
How is the palisade mesophyll layer adapted?
-Cells are packed with many chloroplasts
-Cells are arranged closely together towards the upper surface of the leaf
70
What is the name of the process whereby water is lost by travelling through the stomata?
Transpiration
71
How is the spongy mesophyll tissue adapted?
Tissue is packed loosely for efficient gas exchange.
Covered by a thin layer of water.
71
Describe transpiration.
The loss of water from leaves by evaporation through the stomata.
72
What does the xylem do?
Transports water and minerals from the roots up the plant stem and into the leaves.
72
Describe the xylem vessels
A large hollow tube. The cells that are strengthened by lignin are dead.
73
Describe the transport in xylem tissue.
It’s a physical process that transports water and minerals upwards.
74
What does meristem tissue contain?
Special cells that can turn into any type of cell. They are what allows the plant to grow.
75
What does the waxy cuticle in a plant do?
Protects the leaf against water loss.
76
Describe the transport that phloem tissue does.
The process requires energy, and is the transportation of the products of photosynthesis (including sugars and amino acids) upwards and downwards.
76
How can plants control transpiration?
By opening and closing the stomata.
76
Describe the structure of phloem tissue.
-Contains sieve tubes that make up the phloem end to end.
-Contains companion cells that lie alongside the sieve tubes and provides them with the energy to transport sugars and amino acids in the solution.
76
What is each stoma surrounded by in a leaf?
Guard cells.
77
What factors affect the rate of transpiration?
Temperature, humidity, air movement and light intensity.
78
What is the function of transpiration?
-Provides the water for photosynthesis
-Transports mineral ions
-Cools the leaf as water evaporates
-Provides water that keeps the cells turgid.
79
What can immune reactions initially caused by a pathogen trigger?
Allergies such as skin rashes and asthma.
80
What effect does humidity have on transpiration rate? Explain why.
Higher humidity = lower rate of transpiration. Because it reduces the concentration gradient between the outside and inside of the leaf.
80
What can severe physical ill health lead to?
Depression and other mental illness.
81
What effect does higher temperature have on transpiration rate? Explain why
Higher temperature = higher transpiration rate. Because it increases molecular movement.
82
What effect does air movement have on transpiration rate? Explain why.
Increase in air movement = increase in transpiration rate. Because it removes the water vapour from the leaf’s surfaces.
82
How can you investigate water loss from plant leaves?
-Remove a number of leaves from a bush or tree
-Find the mass of each leaf
-Suspend each leaf from a piece of wire or string
-After a set period of time, re-measure the mass.
83
What effect does light intensity have on transpiration rate? Explain why.
Higher light intensity = Higher rate of transpiration. Because it increases the rate of photosynthesis, and the stomata open so that water diffuses out of the leaf.
84
What is translocation?
The movement of food substances from the leaves to other parts of the plant.
85
What factors affect a person’s physical and mental health?
Diet, lifestyle, stress, situations that occur in a person’s life.
86
Give some examples of non-communicable diseases.
Cancer, diabetes, neurological disorders, heart disease
87
How does smoking increase the risk of cardiovascular disease?
-Damages the lining of the arteries
-Inhalation of carbon monoxide reduces the amount of oxygen that can be carried by the blood
-Nicotine in cigarette smoke increases the heart rate and puts strain on it
-Chemicals in cigarette smoke increase the likelihood of blood clotting
88
What are the effects of smoking on babies?
-Increases the risk of miscarriage
-Babies are more likely to suffer from respiratory infections and an increased risk of asthma
-Long term physical growth and intellectual development of the baby is affected
-Increased risk of birth defects
-Birthweight of the baby is reduced
89
How does alcohol damage the body? (NOT brain)
-Patient experiences weight loss, drowsiness, vomits blood
-Alcohol causes lipids to build up in the liver
-Alcohol damage leads to alcoholic hepatitis
-Cirrhosis of the liver can develop
-Changes in the liver can eventually become irreversible and the reduced ability to process alcohol can also lead to brain damage
90
How does alcohol affect the brain? (In terms of short term damage)
-Slows reaction time
-Causes difficulty walking
-Can impair memory
-Causes slurred speech
-Causes changes in sleep patterns and mood, including increased anxiety and depression
91
How does alcohol affect the brain? (In terms of long term drinking)
-Causes brain shrinkage
-Leads to memory and psychiatric problems
-May result in the patient requiring long-term care
-Brain becomes pulpy
92
What is the impact of alcohol on unborn babies?
-Baby will be smaller in size
-Baby will have a smaller brain with fewer neurons
-Will have long-term learning and behavioural difficulties
-Has distinct facial features (foetal alcohol syndrome)
93
What does obesity lead to?
High blood pressure and the build-up of fatty deposits in the arteries. Increases the likelihood of developing diabetes.
Deposits of lipids in the abdomen increases blood pressure and increases levels of blood lipids.
94
What is Type 2 Diabetes?
Where the body’s cells lose their sensitivity to insulin.
