Biology 2 Flashcards
(109 cards)
1
Q
What is the purpose of the Nucleus?
A
It contains genetic material that controls the activities of the cell.
2
Q
What is Cytoplasm?
A
Jelly-like substance where most chemical reactions happen which contains enzymes. (These enzymes control the reactions.)
3
Q
What is the purpose of the Cell Membrane?
A
Holds the cell together and controls what goes in and out.
4
Q
What is the purpose of Mitochondria?
A
Where most of the reactions for respiration happen. Respiration releases energy that the cell needs to work.
5
Q
What do Ribosomes do?
A
They make the proteins in the cell.
6
Q
Generally, do animal cells have cell walls?
A
No.
7
Q
What is the cell wall of a plant cell made of and what does it do?
A
It’s made of cellulose and supports and strengthens the cell.
8
Q
What does the Permanent vacuole contain?
A
It contains cell sap which is a weak solution of sugar and salts.
9
Q
What are Chloroplasts?
A
They’re where photosynthesis occurs in the cell which make food for the plant.
10
Q
What do the Chloroplasts contain?
A
A substance called Chlorophyll which makes the plant green.
11
Q
What makes Bacteria cells specifically unique?
A
They don’t have a nucleus.
12
Q
What parts do Yeast Cells have?
A
Cell wall, cell membrane, cytoplasm and a nucleus.
13
Q
What parts do Bacteria have?
A
Cell wall, cell membrane, cytoplasm and genetic material (which floats in the cytoplasm.)
14
Q
How are Yeast and Bacteria similar?
A
They are both single-celled organisms.
15
Q
What is Diffusion?
A
It is the spreading out of particles from an area of high concentration to low concentration.
16
Q
What substances can Diffusion happen?
A
Liquids and Gases.
17
Q
What is the link between the concentration of something and the rate of diffusion?
A
The bigger the difference of concentration, the faster the rate of diffusion.
18
Q
How can dissolved substances move in and out of cells?
A
Diffusion.
19
Q
What molecules can diffuse through cell membranes?
A
E.g - oxygen, glucose, amino acids and water.
20
Q
Why can’t big molecules like Starch and Proteins diffuse into cells?
A
They are too big to fit into the membrane.
21
Q
What are Palisade Leaf cells adapted for?
A
Photosynthesis.
22
Q
How are Palisade cells specialised?
A
Packed with chloroplasts with lots crammed at the top so they’re near the light. Tall shape means a lot of surface area is exposed for absorbing CO2 from the air in the leaf. Thin shape means you can have lots of them at the top of the leaf.
23
Q
What are Guard Cells adapted to doing?
A
Opening and closing pores. The adapted functions allow gas exchange and control water loss in a leaf.
24
Q
What shape are Guard Cells and why?
A
Special kidney shape which opens and closes the stomata in a leaf.
25
What happens to the Guard cells where there is a lot of water?
The guard cells fill with water and go plump which makes the stomata open so gases can be exchanged for photosynthesis.
26
What happens to the Guard cells where there is not a lot of water?
The Guard cells lose water and become flaccid making the stomata close. This stops too much water vapour escaping from the plant.
27
What feature makes the opening and closing of the pores work?
They have thin outer walls and thick inner walls.
28
What happens to the Guard cells at night?
They're sensitive to light so close at night to save water without losing out on photosynthesis.
29
What are Red Blood cells adapted to do?
Carry oxygen.
30
How does their shape help them to carry oxygen effectively?
Concave shape gives a big surface area for absorbing oxygen and helps them pass smoothly through capillaries to reach body cells.
31
What are Red Blood Cells full of?
Haemoglobin which is the pigment that absorbs oxygen.
32
Why don't Red Blood cells have a nucleus?
To leave even more room for the haemoglobin.
33
What are the Egg and Sperm adapted for?
Reproduction.
34
What is the main function of the Egg cell?
To carry the female DNA and to nourish the developing embryo in its' early stages.
35
In what 2 main ways has the Egg cell specialised?
It has huge food reserves to feed the embryo. Also, when a sperm fuses with the egg, the egg's membrane instantly changes its structure to stop any more getting in so the offspring end up with the right amount DNA.
36
What is the main function of the Sperm cell?
To get the male DNA to the female DNA.
37
How has the Sperm cell specialised?
It has a long tail and streamlined head to help it swim to the egg. There are a lot of mitochondria in the cell to provide the energy needed. Sperm also carry enzymes in their heads to digest through the egg cell membrane.
38
What are Large Multicellular Organisms (e.g. humans) made up of?roup of similar cells that work together to carry out a particular job.
Organ Systems.
39
What is the process called when cells specialize for a particular job?
Differentiation.
40
When does Differentiation occur?
During the development of a multicellular organism.
41
What is a tissue?
A group of specialised cells that have a similar structure and function.
42
What is an organ?
A group of different tissues that work together to perform a certain function.
43
What is an Organ System?
A group of organs working together to perform a particular function.
44
What are the 4 different tissues used in plants during photosynthesis?
Mesopyll, Xylem, Phloem and Epidermal.
45
What is the equation for Photosynthesis?
Carbon dioxide + Water = Oxygen + Glucose
46
What is Photosynthesis?
Photosynthesis is the process that plants use to produce food/glucose using sunlight.
47
What do the Chloroplasts/Chlorophyll do towards photosynthesis?
The Chlorophyll absorb the sunlight and use all its energy to convert Carbon Dioxide and Water to Oxygen and Glucose.
48
Where in the plant does Photosynthesis happen?
In the leaves.
49
What are the 4 things plants need for Photosynthesis?
1 - Sunlight on the leaf to provide energy for the process.
2 - Chlorophyll is contained in chloroplasts.
3 - Water which reaches the cells via the xylem.
4 - CO2 which diffuses into the leaf.
50
What are the 3 main limiting factors for Photosynthesis?
1 - Light
2 - Temperature
3 - CO2 levels
51
What does 'limiting factor' mean?
It's stopping photosynthesis from happening any faster.
52
How can the limiting factors depend on the environmental factors?
At night, light is the limiting factor. In winter, it's often temperature. If it's warm and bright then the amount of CO2 is limiting.
53
What experiment can you do to work out the ideal conditions for photosynthesis?
Use pondweed to measure the amount of oxygen being produced by putting it in water in a flask and either counting the bubbles or measuring it in a gas syringe in a certain time.
54
How does Light Intensity affects the rate of photosynthesis?
As the light intensity increases, so does the rate of photosynthesis up until a certain point when it no longer becomes the limiting factor.
55
How does Carbon Dioxide affects the rate of photosynthesis?
As the level of CO2 increases, so does the rate of photosynthesis until a certain point where it is no longer the limiting factor.
56
How does Temperature affects the rate of photosynthesis?
As temperature is increased, the rate of photosynthesis goes up because the enzymes needed for photosynthesis work slowly at low temperatures. But if the plant gets too hot (45C) then the enzymes become denatured and don't work.
57
How are Greenhouses the ideal environment for farming?
They help to trap the sun's heat to make sure temperature doesn't become limiting. In winter, a heater can also be used. Light comes in through the glass but artificial light can be used at night. Paraffin heaters give off CO2 so are used.
58
What are the advantages of Greenhouses?
Easy to keep them away from pests and disease, farmers can easily add fertilisers and can create good crops easily.
59
What are the disadvantages for Greenhouses?
It costs money.
60
What 5 things do plants use glucose for?
```
1 - Respiration
2 - Making cell walls
3 - Making Proteins
4 - Store in seeds
5 - Stored as Starch.
```
61
What do plants need respiration for?
Releases energy so they can build new cells and grow.
62
To make cell walls, what is glucose converted into?
Cellulose.
63
How do plants make Proteins?
They combine their glucose with nitrate ions to form amino acids which are then made into proteins.
64
To be stored in seeds, what does Glucose need to be turned into?
Lipids. (Fats and oils.)
65
Why is Glucose stored as Starch?
So it's ready to use when photosynthesis can't happen; like in winter.
66
Where in the plant is this Starch stored?
Roots, stems, and leaves.
67
Why is Starch better for storing than Glucose?
It's insoluble so doesn't draw in lots of water and swell up like glucose.
68
Where do Potato and Parsnip plants store their starch in winter?
Underground.
69
What is a Habitat?
A place where an organism lives.
70
What is the distribution of an organism?
When an organism is found in it's habitat.
71
What 5 environmental factors affect the distribution of organisms?
```
1 - Temperature
2 - Availability of Water
3 - Availability of Oxygen and Carbon dioxide
4 - Availability of Nutrients
5 - Amount of Light.
```
72
What is a Quadrat?
A square frame enclosing a known area used to compare how common an organism is in an area.
73
How would you use a quadrat?
Place 1m squared quadrat on the ground at a random point within the sample area. Count all the organisms in the quadrat. Repeat this as many times as you can. work out the mean number of organisms per quadrat.
74
How do you use a Transect?
Mark out a line in the area you won't to study. Collect data along the line by counting all the organisms that touch the line.
75
How can you make your results more Reliable?
Use as many quadrats/transects as you can in that area and use random smaples.
76
What is a Catalyst?
A substance which increases the rate of reaction without being changed or used up.
77
What is an Enzyme?
A biological catalyst.
78
What are Enzymes made up of?
It's a protein so made up of amino acid chains.
79
What 4 things do proteins act as?
1 - Enzymes
2 - Structural components of tissues
3 - Hormones
4 - Antibodies.
80
What happens to a substance after an enzyme uses it in a reaction?
It splits.
81
What is the Optimum temperature for body enzymes?
37 degrees.
82
What is the ideal pH for enzymes in the stomach?
pH 2.
83
How is Starch broken down in the body?
It is broken down by Amylase which is produced in the salivary glands, the pancreas and the small intestine and is converted into sugars.
84
How are Proteins broken down in the body?
Proteins are broken down by Protease which is produced in the small intestine, stomach and pancreas. They're converted into amino acids.
85
How are Fats broken down in the body?
They are broken down by Lipase which is produced in the stomach. It is converted into fatty acids and glycerol.
86
What is a Catalyst?
A substance which increases the rate of reaction without being changed or used up.
87
What is an Enzyme?
A biological catalyst.
88
What are Enzymes made up of?
It's a protein so made up of amino acid chains.
89
What 4 things do proteins act as?
1 - Enzymes
2 - Structural components of tissues
3 - Hormones
4 - Antibodies.
90
What is the purpose of Bile?
It's produced in the liver and stored in the gall bladder. It is used to neutralise the hydrochloric acid in the stomach so the enzymes can work in the small intestine. It also emulsifies fats into tiny droplets so they have a larger surface area for enzymes
91
What is respiration?
Respiration is the process of releasing energy from glucose which goes into every cell.
92
What do animals use respiration for?
Movement, to build up large molecules from smaller ones, to maintain body temperature.
93
What does exercise do to the body?
Increases your breathing rate and makes you breathe more deeply to meet the demand for extra oxygen and increases the speed of your heart pumping.
94
What is Glycogen?
It's stored in the liver but every muscle has its own store and during exercise the glycogen is converted into glucose to provide more energy.
95
What does Anaerobic mean and what is anaerobic respiration?
Without oxygen and is the incomplete breakdown of glucose which leads to lactic acid.
96
What is the equation of anaerobic respiration?
Glucose = energy + lactic acid.
97
What does the production of lactic acid do?
Causes the muscles to be sore and get muscle fatigue which is where the muscles get tired and stop contacting efficiently.
98
What does your body do to get out of oxygen debt?
You breathe hard to get more oxygen into your blood. Blood flows through your muscles to remove the lactic acid by oxidising it to harmless CO2 and water
99
Why are enzymes used in biological detergents?
They break dwon the animal and plant matter as they remove food and blood stains.
100
Why is Protease used in baby foods?
The protein is pre-digested by protease so it's easier for the baby to digfest.
101
Why is Isomerase used in diet foods?
It converts the glucose into fuctose which is a sweeter product. You use less fructose which is less caloried!
102
What are the advantages of using enzymes in industry?
They're specific so only catalyse the reaction you want it to, they work at lower temp and pressure so saves energy, they work for a long time so you can use them continually and they're biodegradable.
103
What are the disadvantages of using enzymes in industry?
1 - Some people can be allergic to them
2 - They can be denatured even by the smallest change in temperature or pH
3 - They're expensive to produce
4 - Can contaminate with other substances which could affect the reaction.
104
What does DNA stand for?
Deoxyibronucleic acid.
105
Where is DNA found in a cell?
In the nucleus in chromosomes.
106
What is a Gene and what does it contain?
A section of DNA and contains the information to make a specific protein.
107
How do cells make proteins?
They string together amino acids in a particular order.
108
How many amino acids are used to make proteins?
20
109
How is DNA fingerprinting used in Forensic science?
They collect the DNA from the crime scene and cut it up into small sections called bands. They compare the bands from the DNA to the suspects' DNA.
