PPE Biology Paper Revision Flashcards
1
Q
What is the function of the Nucleus in an animal cell?
A
Controls all the activities of the cells and is surrounded by the nuclear membrane. It contains the genes
2
Q
What is the function of cytoplasm in an animal cell?
A
A liquid gel in which the organelles are suspended and where most of the chemical reactions needed for life to task place.
3
Q
What is the function of the cell membrane in an animal cell?
A
Controls the passage of substances into and out of the cell.
4
Q
What is the function of mitochondria in an animal cell?
A
Structures in the cytoplasm where aerobic respiration takes place, releasing energy for the cell.
5
Q
What is function of the ribosomes in and animal cell?
A
Where protein synthesis takes place, making all the proteins needed in a cell.
6
Q
What organelles do animal and plant cells share?
A
- Ribosomes
- Cell Membrane
- Nucleus
- Cytoplasm
- Mitochondria
7
Q
What are the similarities between Prokaryotic and Eukaryotic cells?
A
Both of them have a Cell membrane and Cytoplasm.
8
Q
What are the differences between Prokaryotic and Eukaryotic cells?
A
Eukaryotic genetic material is stored in the nucleus.
Prokaryotic genetic material is stored in plasmids.
9
Q
What organelle does a Prokaryotic cell not have?
A
A nucleus
10
Q
What is cell differentiation?
A
Where a generic embryonic cell becomes specialized into a specific cell type with unique structures and functions.
11
Q
What is the function of a nerve cell?
A
Nerve cells are specialised to carry electrical impulses around the body of an animal.
12
Q
What are the adaptations of a nerve cell and their functions?
A
- Lots of dendrites to make connections to the other nerve cells.
- An axon that carries the nerve impulse from one place to another.
- the nerve endings or synapses are adapted to pass the impulses to another cell or between a nerve cell and a muscle in the body using a special transmitter signal.
13
Q
What is the function of a muscle cell?
A
Muscle cells are specialised cells that can contract and relax.
14
Q
What are the adaptations of a muscle cell and their functions?
A
- They contain special proteins that slide over each other making the fibres contract.
- They contain may mitochondria to transfer The energy needed for the chemical reactions that take place as the cells contract and relax.
- They can store glycogen, a chemical that can be broken down and used in cellular respiration by the mitochondria to transfer energy for fibres to contract.
15
Q
What is the function of a sperm cell?
A
They contain the genetic information from the male parent, and need to travel through water or the female’s reproductive system to reach the egg. They then have to break into the egg.
16
Q
what are the adaptations of a sperm cell and their functions?
A
- A long tail whips from side to side To help move the sperm towards the egg.
- The middle section is full of mitochondria which transfer the energy needed for the tail to work.
- The acrosome stores digestive enzymes for breaking down the outer layer of the egg.
- A large nucleus contains the genetic information to be passed on.
17
Q
What is the function of a root hair cell?
A
- the root hair cell helps a plant take up more water and mineral ions efficiently through the roots.
18
Q
What are the adaptations of a root hair cell and their functions?
A
- They greatly increase the surface area of the roots to increase mineral intake.
- A large permanent vacuum that speeds up the absorption of water via osmosis from the soil.
- They have many mitochondria that transfer the energy needed for active transport into the root hair cell.
19
Q
What is the function of a xylem cell?
A
- They form the transport tissue that carries minerals and water up the plant from the roots.
20
Q
what are the adaptations of a xylem cell and their functions?
A
- The xylem cells are alive when they are first formed but special chemical called lignin builds up in spirals in the walls. The cells die and form long hollow tubes that allow water and mineral ions to move easily through them, from one end of the plant to the other.
- The spirals and rings of Lignin in the xylem cells make them very strong and help them withstand the pressure of water moving up the plant. They also help support the plant stem.
21
Q
what is the function of a Phloem cell?
A
Phloem is the specialised transport tissue that carries the food made by photosynthesis around the body of the plant.
22
Q
what are the adaptations of a phloem cell and their functions?
A
- The cell walls between the cells breaks down to form special sieve plates. These allow water carrying dissolve food to move freely up and down the tubes to where it is needed.
- Phloem cells lose a lot of their internal structures but they are supported by companion cells that helped keep them alive the mitochondria of the companion cells transfer the energy needed to move dissolved food up and down the plant in the phloem.
23
Q
How does diffusion take place?
A
The random movement of particles caused them to move around and bump into each other and spread out over a period of time.
24
Q
Why is diffusion so important in organisms?
A
Because diffusion allows gases like oxygen to pass from your lungs to your red blood cells to keep the body alive.
25
What affects the rate of diffusion?
- Difference in concentration in two areas the bigger the concentration the quicker the rate of diffusion.
- Increase temperature creates more energy meaning the particles move quicker and their random movement speeds up to increase the rate of diffusion.
26
What is osmosis?
- The movement of water molecules from a area of high water concentration to an area of low water concentration across a partially permeable membrane.
27
What is the difference between osmosis and diffusion?
Osmosis only allows water to diffuse whereas diffusion allows all things to move through the concentration gradient.
28
Why is osmosis important for animal cells?
If the surrounding fluid of a cell becomes hypertonic then water will move into the cell making the cell swell and burst.
29
Why is osmosis important in plant cells?
Plants rely on osmosis to support their stems and leaves. Water moves into plant cells be osmosis. This causes the vacuole to swell, which presses the cytoplasm against the cell wall. The pressure builds up until no more water can physically enter the cell.
30
how does active transport work?
It moves molecules across a cell membrane against the concentration gradient requiring energy.
31
what is the importance of active transport in cells?
To help with movement of particles that are against the concentration gradient like glucose out of your gut and kidney tubules into your blood which are often done against a large concentration gradient.
32
what is the role of the chromosome in a cell?
Chromosomes carry the genes that contain the instructions for making both new cells and all the tissues and organs needed to make an entire new organism.
33
What is the importance of the cell cycle?
The cell cycle is crucial for growth, development and repair in multicellular organisms. It involves cell division particularly mitosis which ensures the new cells are produced with identical genetic information to the parent cell.
34
How do cells divide by mitosis?
mitosis is a type of cell division where a parent cell devising into two identical daughter cells due to the chromosome splitting to either side of the nucleus.
35
how does cell differentiation vary in animals and plants?
Animal cell embryos become a specialised early in their development whereas most plants sell embryos are able to differentiate all throughout their lives.
36
How are stem cells different to other body cells?
Stem cells are differ differentiated whereas other body cells have specific functions
37
what is the function of stem cells in embryos?
They can differentiate into any type of cell forming all the tissues and organs needed for a functioning organism
38
what is the function of stem cells in adult animals?
Stem cells primarily function to replenish and repair tissues that have been damaged or have lost cells.
39
What is the function of stem cells in plants?
They play crucial role in growth and development. They can differentiate into any type of plant cell throughout the plants life.
40
How do specialise cells become organised into tissues?
Once cells have differentiated, they are often grouped together with similar sales to form tissues.
41
How do several tissues work together to form an organ?
The tissues group together and coordinate their actions to carry out a function and create an organ.
42
What is a catalyst?
A substance that changes the rate of a chemical reaction without being changed by the reaction itself.
43
what does the metabolism of the body involve?
All the chemical reactions that occur inside living cells, including both breaking down molecules and building up molecules.
44
How does temperature affect enzyme action?
The rate of enzyme reactions increases of the temperature increases up to about 40°C. After this the protein structure of the enzyme is affected by the high temperature and becomes denatured rapidly decreasing rate of reactions. Optimum temperature for most human enzymes is 37°C.
45
What is the effect of pH on enzyme action?
PH levels can stop enzymes working completely forces hold folded chains in place and a change in pH affects these forces as a result the specific shape of the active site is lost so the enzyme can no longer act as a catalyst.
46
What enzymes can work best above 40°C?
bacteria living in hot Springs survive at temperatures up to 80°C and higher.
47
What is the role of hydrochloric acid to make digestion more efficient?
The protease enzyme Pepsin works best than an acidic pH. Your stomach produces a relatively concentrated solution of hydrochloric acid from the glands this acid allows your stomach protease enzymes to work very effectively.
48
what is the role of bile in making digestion more efficient?
once your food moves on to the small intestine some of the enzymes that catalysed digestion are made in your pancreas they all work best in an alkaline environment. The acidic liquid coming from your stomach needs to become an alkaline mixture in your small intestine so this can happen your liver makes a green yellow alkaline liquid called bile by was stored in your gallbladder until it is needed.
49
How are substances of the blood transported to and from the other cells?
Plasma carries red blood cells, white blood cells and platelets suspended in it. It also carries many dissolved substances around your body.
50
What different components is blood made up of?
Red blood cells, white blood cells and platelets
51
what is a red blood cell and its function?
- There are more red blood cells than any other type of blood cell in your body
- These cells pick up oxygen from the air in your lungs and carry it to the cells where it is needed
- They are by concave discs being concave on both sides gives them an increased surface area to volume ratio for diffusion
- They are packed with a red pigment called haemoglobin that binds to oxygen
- They have no nucleus making more space for haemoglobin
52
what is a white blood cell and its function?
White blood cells are much bigger than red blood cells and there are fewer of them.
- They have a nucleus in form part of the bodies defence system against harmful microorganisms
- Some form antitoxins against poisons made by microorganisms
- Yet others engulf and digest invading bacteria and viruses
53
What is a platelet and its functions?
- Platelets are small fragments of cells.
- They helped the blood clot at the site of a wound
- It helps prevent bacteria entering the body .
54
how does the blood flow around the body?
Blood is carried around your body in three main types of blood vessels each adapted for a different function, arteries, veins and capillaries.
55
What is the function of an artery?
- Your arteries carry blood away from your heart to the organs of your body.
- This blood is usually bright red oxygenated blood
- Arteries have thick walls containing muscle and elastic fibres.
56
what is the function of the veins?
- The veins carry blood away from the organs towards your heart.
- This blood is usually low in oxygen and therefore a deep purple-red colour.
- Veins have much thinner walls than arteries and often have valves to prevent the backflow of blood.
57
what is the function of the capillaries?
- Capillaries for a huge network of tiny vessels linking the arteries and veins.
- Capillaries are narrow with very thin walls this enables substances such as oxygen and glucose to diffuse easily out of your blood and into your cells.
58
Why are valves crucial in the circulatory system?
Valves prevent backflow so that oxygenated blood does not flow back into the bloodstream.
59
what is the importance of the double circulatory system?
It makes our circulatory system very efficient allow allowing fully oxygenated blood to return to the heart from the lungs. This blood can then be sent off to different parts of the body a high-pressure so more areas of your body can receive fully oxygenated blood quickly.
60
how does the heart keep its natural rhythm?
The pacemaker region controls the basic rhythm of your heart via a built-in electrical system.
61
how does an artificial pacemaker work?
Artificial pacemakers send strong regular electrical signals to your heart that stimulated to beat properly
62
What can artificial hearts do?
they can support the body and give diseased hearts a rest
63
How are gases exchanged in the alveoli of the lungs?
Oxygen diffuses into the blood across the very thin alveolus walls and red blood cells circulate around the body
64
What is the function of an epidermal tissue?
They cover the surface of the plant and protect them
65
what is the function of the palisade mesophyll?
Contains lots of chloroplast which carry out photosynthesis.
66
what is the function of spongy mesophyll?
Contain some chloroplast for photosynthesis but also has big air spaces and a large surface area to make the diffusion of gas is easier
67
what substances are transported in plants?
- Sugar is made by photosynthesis from the leaves to the rest of the plant
- water and mineral ions from the roots to the stem and leaves
68
what is transpiration?
The process where plants lose water vapour from their leaves through tiny pores called stomata.
69
What is the role of the stomata and guard cells in controlling gas exchange and water loss in a plant?
Stemmata are small openings in the leaf that can be opened when the plant needs to allow air into the leaves at the same time. Oxygen produced by photosynthesis is removed from the leaf by diffusion into the surrounding air the size of the stomata and their opening and closing is controlled by the guard cells.
70
What are the factors that affect the rate of transpiration?
temperature humidity, the amount of air movement and light intensity
Anything that increases the rate of photosynthesis will increase the rate of transpiration.
71
What is health?
A state of complete physical mental and social well-being, not the just absence of disease or infirmity.
72
What are the different causes of ill health?
- Diet
- Stress
- Life Choices
73
how do health problems interact?
- Viruses living in sales can trigger changes that lead to cancers
- The immune system of your body helps you destroy pathogens and get better
- Immune reactions initially caused by pathogen can trigger allergies to factors in the environment
- Physical and mental health are often closely linked severe physical ill health can lead to depression and other mental illnesses
74
what are pathogens?
A microorganism that can cause disease and other organisms whether they be animals or plants
75
How can pathogens cause disease?
By either producing toxins that damage tissues or by invading and reproducing within cells causing cellular damage which caused the individuals to feel ill
76
How are pathogens spread?
- By air
- By direct contact
- By water
77
Why are bacteria cultured at lower temperatures in schools than an industry?
Because culturing bacteria at 37° would create a high risk of growing dangerous pathogens in schools. They are incubated at 25°C.
78
How can the spread of disease be reduced or prevented?
- Hygiene - hand washing coughing or sneezing into a tissue
- Isolating infected individuals
- Destroying or controlling vectors like rats or mosquitoes
- Vaccination
79
What are some examples of animal diseases caused by viruses?
- Measles - Fever and red skin rash
- HIV/AIDS - Damaged immune system
80
What are some examples of plant diseases caused by a virus?
- Tobacco Mosaic Virus - Discolouration of leaves and destruction of plant cells.
81
What are some examples of animal diseases caused by bacteria?
- Salmonella - Fever, abdominal cramps, vomiting, and diarrhoea.
- Gonorrhoea - Thick yellow discharge from vagina or penis.
82
What are some examples of animal diseases caused by fungi?
- Athletes Foot - fungal growth around feet
83
What are some examples or plant diseases caused by fungi?
- Rose Black Spot - Purple or black spots develop on the leaves of plants.
84
What are some examples of animal diseases caused by protists?
- Malaria - Fever and Shaking
85
How can the spread of diseases be reduced or prevented in protists and fungi?
- use insecticide nets to prevent mosquitoes biting humans and passing on the protists
- Use insecticides to kill mosquitoes in homes and offices
- Preventing the vectors from breeding by removing standing water
86
How does your body stop pathogens getting in?
- Nose Hairs - to trap air particles that contain pathogens
- Mucus - Same function as hairs
- Acid production - Destroys pathogens in the immune system
87
What are the two types of Plant protection against pathogens and herbivores?
- Physical Barriers - Bark on trees, Thorns to harm predators.
- Chemical Barriers - Poisons etc.
88
How does your immune system work?
- Cells have unique proteins on the surface called antigens. The antigens on the microorganisms that get into body are different from the ones on your own cells.
- Your white blood cells then make specific antibodies, which join up with the antigens and inactivate or destroy that particular pathogen.
- Some of your WBC remember the right antibody needed to destroy a particular pathogen meaning in the future you are immune to the disease
89
How do vaccines protect you against disease?
- Vaccination involves giving you a vaccine made of dead or inactive form of disease-causing microorganism. It stimulates your bodies natural immune response to invading pathogens.
- Once the natural immune response activated your body now has the right antibodies to fight the illness in the future
90
What are medicines?
- Chemical substances used to treat or prevent diseases.
91
How do medicines work?
- They relieve symptoms
- THEY DO NOT KILL THE PATHOGEN
- This reduces symptoms.
92
What can antibiotics treat?
- Antibiotics can be used to treat bacterial diseases by killing the bacterial pathogens.
93
How can antibiotics not be used?
- They cannot kill pathogens and so they have no effect on diseases caused by viruses
- Strains of bacteria that are resistant to antibiotics are evolving meaning some types of bacteria cannot be killed by antibiotics.
94
what are some of the drugs traditionally extracted from plants?
- Digitalis and Digoxin from foxgloves
- Aspirin from the bark of willow trees
95
How was penicillin discovered?
- By Alexander Fleming noticing a ring around bacteria where it had been killed on the agar gel
96
What are the stages involved with testing and trialling new drugs?
- Pre-clinical trials - Drug tested on cells & tissues to test efficacy & side effects
- Pre-clinical trials - Animal testing-Checks if drug is safe throughout a whole organism
- Clinical Trial - Human Testing-Very low doses given > Further clinical trials will determine optimum dose
97
Describe the process of phagocytosis.
- Pathogen is identified
- Binds to phagocyte
- Cytoplasm surrounds & engulfs the pathogen
- Pathogen is killed and digested to prevent it spreading further
- The indigestible parts of the pathogen are removed to prevent the spread.
98
What are some examples of non-communicable diseases?
- Heart disease, diabetes
99
What can viruses not do?
- Reproduce or replicate- Requiring them to find a host cell meaning they are non living
- Viruses do not have a nucleus
100
Describe the process of antibodies.
- pathogens contain antigens on their surface
- Then white blood cells detect these antigens and produce antibodies and response
- The antibodies lock onto the antigens rendering them useless while other white blood cells now destroy the antigens and pathogens
101
Describe the process of antitoxins
- bacteria can produce toxins that are harmful to the body
- White blood cells detect the toxins and produce antitoxins
- The antitoxins neutralise the effect of toxins
102
What is MRSA?
A bacteria that is hard to beat with antitoxins
103
what are some examples of communicable diseases?
Malaria, measles and hepatitis
104
what makes a good drug/medicine?
Effective, safe stable and successfully taken into and removed from the body
105
What is a drug tested for during drug testing?
- Toxicity - a measurement of the dosage needed of a particular substance to damage a living organism
- Efficacy - the ability of a drug to cure condition or relief symptoms
- Optimum dose - the most effective amount of drug needed to cure the disease safely
106
how are monoclonal antibodies produced?
- Monoclonal antibodies are proteins that are produced to target particular cells or chemicals in the body
- mammal lymphocytes are combined with a type of tumour cell to make a cell called a Hybridoma.
- The hybridoma cells make specific antibodies and divide the cells are cloned. Colonial antibodies are separated purified and can be used.
107
how are monoclonal antibodies used?
- Pregnancy tests
- Diagnosis of disease
- Measuring and monitoring hormones and other chemical chemicals in the blood
- Research to locate specific molecules in a cell or tissue
108
what are the advantages of using mono colonial antibodies?
- they only bind to the specific disease or damage cells that need treatment
109
What is a tumour?
- A lump or growth of abnormal cells that form when cells divide uncontrollably.
110
What is a benign tumour?
- A tumour that is non cancerous
111
What is a malignant tumour?
A tumour that is cancerous
112
how does smoking affect the risk of developing cardiovascular disease?
- It majorly increases the risk
- The toxic gases found in tobacco take up some of the oxygen carrying capacity in your blood.
113
What is the effect of smoking on unborn babies?
- If the mother’s blood is carrying carbon monoxide from a cigarette the fetus may not get enough oxygen to grow causing complications.
114
What is a carcinogen?
- Any substance, agent or factor that can cause or increase the risk of cancer
115
what are the raw materials and energy source of photosynthesis?
- Carbon dioxide and water
- Light energy
116
what type of reaction is photosynthesis?
Endothermic
117
What is the equation for photosynthesis?
Carbon Dioxide + water -light—> glucose + oxygen
118
what factors limit the rate of photosynthesis?
- Light
- Temperature
- Carbon dioxide concentration
119
How do plants use the glucose they make?
The glucose is broken down using oxygen to provide energy for the cells
120
