Biology Final Ka Year 10 Flashcards
(118 cards)
1
Q
What are eukaryotic cells and what are examples of them?
A
Complex cells.
Animal and plant cells
2
Q
What are prokaryotic cells and what is an example of one?
A
Smaller and simpler cells.
E.g. Bacteria
3
Q
Label animal cell diagram on sheet
A
.
4
Q
Label plant cell diagram on sheet
A
.
5
Q
Label bacterial cell diagram on sheet
A
.
6
Q
What is the equation for magnification?
A
Magnification = image size ÷ real size
7
Q
How do you convert micrometers into mm?
A
Divide by 1000
8
Q
What makes chemical reactions work?
A
Enzymes
9
Q
What is a catalyst?
A
A substance which increases the speed of the reaction without being changed or used up in the reaction
10
Q
How could you speed up a chemical reaction?
A
Raise the temperature
11
Q
Why do living things produce enzymes?
A
Living things produce enzymes that act as biological catalysts which reduce the need for big temperatures and we only have enzymes to speed up useful chemical reactions in the body
12
Q
What are proteins? What are they made up of?
A
They are large proteins which are made up of chains of amino acids.
13
Q
What do all enzymes have?
A
An active site with a unique shape that fits onto the substances involved in a reaction
14
Q
What happens if the substrate doesn’t match the enzymes active site?
A
The reaction won’t be catalysed because enzymes only catalyse one specific reaction
15
Q
Label enzyme model on sheet
A
.
16
Q
What happens if enzymes get too hot?
A
The bonds break and change shape so they can’t fit into their active site any more. The enzyme becomes denatured
17
Q
What does the enzyme amylase do?
A
Catalyses the break down of starch to maltose.
18
Q
What will happen to iodine solution if starch is present?
A
It will change from browny-orange to blue-black
19
Q
How can you investigate how pH affects amylase activity?
A
- put drops of iodine into the wells of a sporting tile
- put a tripod over a Bunsen burner and put a beaker of water on top and heat until it’s 35°C using a thermometer
- add 1cm³ of a buffer solution with a pH of 5 to a boiling tube and place in water
- wait for 5 mins when add 5cm³ of a starch solution to the tube
- mix the contents and start a stop watch and measure how long it takes for the amylase to break down all of the starch
- place a sample from the tube every 30 secs and put a drop into a well
- when the solution remains brown starch is no longer present
20
Q
What is a enzymes optimum temperature?
A
40°C
21
Q
What are the microorganisms that cause disease?
A
Pathogens, they can be: bacteria, viruses, fungi, Protists
22
Q
How do bacteria make someone ill?
A
Thy release toxins into their host making them ill
23
Q
How do viruses make a person ill?
A
They attach to a cell, injects DNA, DNA replicates using host, new vital DNA is released
24
Q
Explain what a pathogen does when it enters the body.
A
- enters body
- reproduces rapidly
- bacteria make harmful toxins, viruses damage cells
- symptoms develop
25
How can diseases be spread?
* droplet infection
* touching
* break in the skin
* via animal bite
* vector organism
* sexually transmitted
* food and drink
26
How can u stop the spread of disease?
* clean water supplies
* sewage treatment
* hand washing in hospitals
* personal hygiene
* food storage
* isolation
* disinfectants
27
What conditions do microbes need to work?
* food and oxygen
* warmth
* moisture
* correct pH
* correct salt concentration
28
How can we prevent microbes growing?
* freezing
* canning
* pickling
* drying
* salting
* pasteurisation
29
What does aseptic mean?
Without microorganisms
30
Why might you use the aseptic technique?
Any unwanted bacteria will not contaminate your experiment.
| Any bacteria from your experiment will not escape the plate
31
What does the body do to protect you from disease?
* Skin- acts as a barrier
* Scabs- clots form to seal wounds
* Breathing- mucus traps pathogens and cilia helps remove it
* stomach- acid destroys food pathogens
* enzymes - special enzymes in urine, tears and saliva kill bacteria
* white blood cells - destroy pathogens that enter the blood
32
How do white blood cells destroy microorganisms?
They ingest them
33
How do white blood cells target particular bacteria or viruses?
They produce unique antibodies for each type of bacteria or virus. Once they have produced antibodies for then, they can produce them again rapidly if the pathogen enters the body again
34
What are antitoxins and what produces them?
They are made by the white blood cells and neutralise the toxins made by bacteria that make you ill
35
What happens if antibodies or antitoxins are not made fast enough?
They overwhelm the body so you get ill or die
36
How do antibodies prevent disease?
Because they are ready in your body for the next time you get a disease you've already had so they can be produced fast enough for symptoms to not occur
37
How do vaccines work?
You are injected with a dead or harmless version of a pathogen. Your white blood cells produce antibodies. If you come into contact with the real version of the pathogen you white blood cells can respond more quickly. Infection is prevented
38
What are live altered pathogens?
Live altered pathogens are most effective as they can still reproduce and so trigger a full immune response
39
What are dead pathogens?
Dead pathogens don't trigger a big enough initial response and so a second dose is needed.
40
What is active immunity?
Which blood cells which produce a specific antibody have been produced. Provides permanent immunity
41
What is passive immunity?
Antibodies are directly given. Only provide temporary immunity.
42
What is herd immunity theory?
The more people in a population that are vaccinated then the more likely you are to prevent infection of the non vaccinated
43
What do antibiotics do?
Help to cure bacterial diseases by killing infective bacteria inside the body by destroying bacterial cell walls that kill the bacteria
44
What can antibiotics not kill?
Viral pathogens which live and reproduce inside the cells
45
What do antiseptics and disinfectants do?
Kill bacteria outside of the body by are to poisonous to be taken internally
46
Why is it hard to design vaccines against viruses?
Because they are tolerant of mutations
47
What must drugs be?
Effective - prevent or cure the target disease or make you feel better
Safe - must not be too toxic or have very bad side effects
Stable - possible to store for a period of time
48
Why must the correct dose of a drug be given?
So it works while reducing the risk of side effects
49
Why do we test drugs in animals?
To see any side effects and predict safe doses
50
Explain the process of a drug trial
```
Discovery (1-10) years
Preclinical: lab + animal tests
Phase 1 - Healthy human being
Phase 2 - small number of patients
Phase 3 - bigger clinical trials
MHRA review approval
Licensed
Additional post-market testing
```
51
What is the placebo effect?
Thinking something is working when its actually not
52
What are double blind trials and why are they carried out?
The placebo effect is often stronger than the drugs effect. These trials are carried out to avoid bias. Two groups are allocated: one has the real thing, other has the fake. Neither patients or doctors know which one is which.
53
What makes a double blind trial fair?
Same age range, same gender mix, same general health, fitness, BMI
54
What problems can occur with the reviews from medical professionals when looking into drug trials
* finding pharmaceutical companies that will do it
* lack of reporting negative results
* over exaggeration of results
* under reporting of side effects
55
What should you look at when carrying out a drug trial?
The hypothesis- what you think is going to happen
Risk assessment - potential hazards and what you'll do is something happens
Independent variable -
Dependant variable
Controlled variables
Method
Conclusion
56
What is the flower part of a plant?
Contains the male and female sexual organs
57
What is the leaf?
Carries out photosynthesis
58
What is the stem?
Supports leaves and flowers
59
What are the roots?
Take up water and minerals from the soil
60
Label the leaf diagram
.
61
What are some leaf adaptations?
Broad, large surface area for absorbing light
Contain chlorophyll in chloroplasts to absorb light energy
Air spaces to allow carbon dioxide to get to the cells and oxygen to leave by diffusion
Veins to bring water too cells
62
What do plants need for photosynthesis?
Carbon dioxide and water
63
Where is carbon dioxide obtained in a plant?
By diffusion into the cells of the leaves
64
What is the epidermal?
Covers parts of the plant and protects them
65
What is the mesophyll?
Tissues contain lots of palisade cells which have many chloroplasts and therefore carry out most photosynthesis
66
What is the Xylem?
Transports water and dissolved mineral ions from the root to the leaves
67
What is the phloem?
Transports sugar from the leaves around
68
How do aquatic plants photosynthesise?
By absorbing carbon dioxide dissolved in the water around them
69
Why do all organisms need food?
For respiration, growth and reproduction
70
Explain the process of photosynthesis
Energy is transferred from the environment to the chloroplasts by light, it is then transferred to the convert carbon dioxide from the air, plus water from the soil into a sugar called glucose. Oxygen is released as a by-product
71
What type of reaction is photosynthesis and why?
Endothermic reaction because it needs an input of energy from the environment
72
What is the equation for photosynthesis?
Carbon dioxide + water --> glucose + oxygen
6CO₂ + 6H₂O --> C₆H₁₂O₆ + 6O₂
73
What are the factors that effect photosynthesis?
Light, temperature and carbon dioxide concentration
74
How does light effect photosynthesis?
The more the light the more photosynthesis can take place
75
How does temperature effect photosynthesis?
As the temp rises, the rate on photosynthesis increases. Photosynthesis is controlled by enzymes, most are denatured about 40-50°C. Is the temp is too high, the rate of photosynthesis decreases
76
What does it mean for a plant that is dark and has a lot of chlorophyll?
It does not need a lot of sunlight to photosynthesise
77
Why do plants need glucose?
For respiration, energy stores and making material for growth
78
What are amino acids built up into?
Proteins to be used in cells
79
What experiment can we use to test the effects of light on photosynthesis? And explain the method. What could you do to make it more accurate?
The pond weed experiment. Place a lamp from 10cm-50cm away from pondweed in water. Record the amount of bubbles released in one minute.
Use technology or measure CO₂ levels as well.
80
What does cellulose do?
Used to make cell walls and forms the fibre in our diet
81
What are fats used for?
Used in cell membranes. Sometimes oils act as energy stores in the seeds
82
What are nitrates used for?
Protein
83
What is phosphate used for?
For photosynthesis and respiration reactions and to make cell membranes and DNA
84
How do you test for starch in a leaf?
Place the leaf in a test tube and boil. Place leaf in warm alcohol to extract the chlorophyll. Place leaf in beaker of warm water. The leaf will turn blue-black if starch is present
85
What all work together to provide your cells with the glucose and oxygen you need for respiration?
Digestive system, lungs and circulatory system
86
What type of reaction is aerobic respiration and why?
An exothermic reaction because a fuel reacts with the oxygen to release energy
87
What is the equation for respiration?
Glucose + oxygen --> CO₂ + water + energy
C₆H₁₂O₆ + O₂ --> CO₂ + H₂O
88
What do birds and mammals obtain?
A constant internal body temperature
89
What is the equation for anaerobic respiration?
Glucose --> lactic acid + energy
90
What is oxygen debt?
The amount of oxygen needed to break down lactic acid to CO₂ and H₂O
91
Explain the ruler stick drop test
* student A sits with her elbow resting on the edge of a table
* student B holds the ruler with the bottom of the ruler level with the thumb of student A
* student B drops the ruler
* student A catches the ruler and records the distance
92
What is the endocrine system?
Produces the hormones in your body and controls many aspects from birth to adulthood
93
How does the endocrine system work?
It is made up of glands that secrete chemicals called hormones directly into the bloodstream. The blood carries the hormone to its target organ where it produces an effect. Receptors on the cell membrane picks up the hormone, triggering a response in the cell.
94
What lowers blood glucose?
Insulin
95
What increases blood glucose levels?
Glycogen
96
What is the pituitary gland?
The master gland that coordinates many of the endocrine glands and other glands
97
What are some slow acting hormones?
Growth hormone
| Oestrogen and testosterone (reproduction)
98
What are some rapid response hormones?
Insulin - blood glucose
| Adrenaline -fight or flight
99
What is glucose?
The sugar used in respiration
100
What is glycogen?
A storage carbohydrate made of glucose found in the liver and muscles
101
What is glucagon?
A hormone made in the pancreas that stimulates the liver to break down glycogen to glucose
102
Where is glucose stored?
As a carbohydrate known as glycogen in the liver and muscles
103
Where are glycogen and insulin made?
In the pancreas
104
What is it called when the glucose level is too high?
Hyperglycaemia
105
What is it called when the glucose level is too low?
Hypoglycaemia
106
What happens to the demand for glucose during exercise?
It increases as the level of glucose in the blood begins to fall. Our pancreas responds by releasing glucagon. This causes the glycogen in the liver to be converted back into glucose in the blood stream
107
What is type 1 diabetes?
When the pancreas cannot secrete enough insulin, possible due to a deficiency in the gene coding for insulin or damage to pancreas cells.
108
What is type 2 diabetes?
When the pancreas still produces insulin but the muscles and liver cells stop responding to it properly. Commonly associated with obesity
109
What are some symptoms of diabetes?
* blood glucose levels rise and stay high
* glucose passes in urine
* hunger and thirst (water and salt through the urine)
* lack of energy
110
How do you treat type one diabetes?
Replacement insulin before meals. Allows the cells to take up glucose and for some to be converted to glycogen in the liver preventing it from rising too high.
111
How do you treat type 2 diabetes?
* do regular exercise
* eat a balanced diet
* lose weight
112
What is osmosis?
The movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration
113
Explain roughly the effect of sugar solutions on plant tissue experiment (potato)
A range of solutions with different concentrations of sugar (from pure water to strong sugar) in beakers. Equal mass cylinders of potato are placed into each beaker and left for 24hours. The potato cylinders in the strong solutions will be smaller in mass then the ones in the weaker solutions.
114
Explain roughly the microscopy experiment (onion)
Place an epidermal layer of onion onto a glass slide and add a water onto it. Add a drop of iodine which is a stain and will highlight objects in a cell. Place a cover slip on top.
115
Label microscope diagram on sheet
.
116
What are starch molecules made up of?
Many glucose molecules
117
What are protein molecules made up of?
Many amino acids. Protease breaks down protein molecules
118
What are fat molecules made up of?
Fatty acid and glycerol molecules. Lipase breaks down fat molecules
