Bio Final Exam: big pack Flashcards
(117 cards)
1
Q
What do all living organisms have in common? (MRS C GREN)
A
-Movement
-Respiration
-Sensitivity
-Control
-Growth
-Reproduction
-Excretion
-Nutrition
2
Q
What are the subcellular structures found in animal and plant cells? (5)
A
-Nucleus
-Cytoplasm
-Cell membrame
-Mitochondria
-Ribosomes
3
Q
Nucleus:
A
-Contains the genetic material, which codes for a particular protein
-Enclosed in a nuclear membrame
4
Q
Cytoplasm:
A
-Liquid substance in which chemical reactions occur
-Contains enzymes (biological catalysts, i.e proteins that speed up the rate of reaction
-Organelles are found in it
5
Q
Cell membrame:
A
-Contain receptor molecules to identify and selectively control what enters and leaves the cell
6
Q
Mitochondria:
A
-Where aerobic respiration reactions occurs, providing energy for the cell
7
Q
Ribosomes:
A
-Where protein synthesis occurs
-Found on a structure called the rough endoplasmic reticulum
8
Q
What do Plants contain?
A
E.g. cereals (maize) or herbaceous legume (peas)
-Multicellular organisms
-Contain chloroplats
-Cellulose cell walls which provide strength to the cell
-Contain a permament vacuole, stores cell sap + improves cell’s rigidity
-Store carbohydrates as starch or surcrose
9
Q
What do Animals contain?
A
E.g. mammals (humans) and insects (flies)
-Multicellular
-Can’t photosynthesise
-Don’t have cell walls
-Have nervous systems in order to coordinate movement
-Store carbohydrates as glycogen
10
Q
What do Fungi contain?
A
-E.g. Mucor has a typical hyphal structure, yeast is single celled
-body is usually organised into a mycelium of thread-like structures called hyphae
-cell walls made of chitin
-feed by saprotrophic nutrition
-store carbohydrates as glycogen
11
Q
What are Protoctists?
A
-Single-celled organisms
-Some features like animal cells, such as Amoeba, that live in pond water
-Some features like plant cells + have chloroplasts, such as Chlorella
12
Q
What are Eurokaryotes?
A
-> organisms that have a nucleus and organelles that are found within a plasma membrane
13
Q
What are Prokaryotes?
A
-> don’t have a nucleus or membrane-bound organelles
14
Q
What does Bacteria contain?
A
E.g Lactobacillus bulgaris (used to make yoghurt), Pneumoccocus (causes pneumonia)
-single-celled + very small
-have a cell wall, cell membrane, cytoplasm + plasmids
-lack a nucleus but have circular chromosomes of DNA
-some can carry out photosynthesis but they mainly eat off other organisms, either dead or alive
15
Q
What are Pathogens?
A
-Disease-causing organisms and can be fungi, bacteria, protoctists or viruses
16
Q
What does a Virus contain?
A
E.g. Tobbaco mosaic virus (prevents chloroplast formation), influenza virus (causes ‘flu’), HIV (causes AIDS)
-smaller than bacteria
-some are parasite: it depends on another organism to grow and reproduce
-infect all types of living organisms
-they have a protein coat around some genetic material (DNA or RNA)
17
Q
Why is Bacteria a pathogen?
A
E.g. Salmonella (food poisoning)
-can reproduce many times through binary fission
-produce toxins that can damage cells
18
Q
Why are Protoctists a pathogen?
A
E.g. plasmodium -> malaria
-parasitic- use animals as their hosts to live in
19
Q
Why is Fungi a pathogen?
A
E.g. Athlete’s foot
-produce spores that can spread in the wind or between people
-can treat with fungicides
20
Q
Organelles:
A
specialised subcellular structures found within living cells
21
Q
Cells:
A
basic structural unit of a living organism
22
Q
Tissues:
A
group of cells with similar structures, working together to perform the same function
23
Q
Organs:
A
group of tissues, working together to perform specific functions
24
Q
Organ Systems:
A
group of organs with similar functions, working together to perform body functions
25
What are only found in plant cells?
-Chloroplasts
-Permament vacuole
-Cell wall
26
Chloroplasts:
-Where photosynthesis takes place, providing food for the plant
-Contains chlorophyll pigment (which makes it green) which harvests the light need for photosynthesis
27
Permament vacuole:
-Contains cell sap
-Found within the cytoplasm
-Improves cell's rigidity
28
Cell wall:
-Made from cellulose
-Provides strength to the cell
29
What are Carbohydrates?
-Made of carbon, oxygen and hydrogen
-They are polymers that break down into simple sugars
30
What are Proteins?
-Made of carbon, oxygen, hydrogen, sulfur, nitrogen and phosphorous
-They are polymers that are broken down into its monomers: amino acids
31
What are Lipids (fats and oils)?
-Made of carbon, oxygen and hydrogen
-They are large polymers that are broken down into 3 fatty acids molecules + a glycerol molecule
32
What is the test of glucose?
Benedict's solution:
If glucose is present: brick red
If glucose is not present: remain brown
33
What is the test for starch?
Iodine solution:
If starch is present: turn blue-black
If strach is not present: remain brown
34
What is the test for protein?
Biuret solution:
If protein is present: turn purple
If protein is not present: remain blue
35
What is the test for lipids?
Ethanol:
If lipids are present: milky white emulsion will form
If lipids are not present: remain colourless
36
What are Enzymes?
-Biological catalyst
-They are protein molecules and the shape of the enzyme is vital to its function because each enzyme has its own active site where the subsrtate binds
37
How does the Effect of temperature affect enzymes?
-they optinum is around 37º
-increase in tem. = increase rate of rxn, if it goes above the 37º it rapidly decreases and the rxn stops (bonds are broken if too hot9
-this changes the shape of the active site = substrate can no longer fit in), the enzyme is denatured
38
How does the Effect of pH affect enzymes?
-optinum pH = 7, but some are produced in acidic conditions (eg: stomach, has a lower pH)
-if the pH is too high or low, the forces hold the amino acid chains that make up the protein will be affected
-same as the active site in the effect of temp.
39
What is Diffusion?
-> the spreading out of the particles in a net movement from an area of higher concentration to an area of lower concentration
-passive process = no energy is required
-molecules have to be small in order to move across (oxygen, glucose, amino acids, water...), large molecules (starch, protein...) can't
40
How does the Concentration gradient affect the rate of movement?
-greater difference in concentration = faster rate of diffusion
-this is because more particles are randomly moving down the gradient than are moving against it
41
How does the Temperature affect the rate of movement?
-the greater the temperature, the greater the movement of particles, resulting in more collisions and therefore a faster rate of diffusion
42
How does the Surface area: volume ratio affect the rate of movement?
-the greater the s.a, the more space for particles to move throughm resulting in a faster rate of diffusion
43
How does Distance affect the rate of movement?
the further the particles have to travel the longer it will take
44
What is Osmosis?
-> the movement of water from a less concentrated solution to a more concentrated one through a partially permeable membrame
-a dilute solution of sugar has a high
concentration of water (high water potential) and vv
-water moves from a dilute solution to a concentrated solution because it moves from ana area with high water potential to low water potential- down a concentration gradient
-it is passive
45
What is an Isotonic solution?
If the concentration of sugar in a external solution is the same as the internal, there will be no movement and the solution is said to be isotonic to the cell
46
What is a Hypertonic solution?
If the concentration of sugar in an external solution is higher than the internal, water moves out, and the solution is said to be hypertonic to the cell
47
What is a Hypotonic solution?
If the concentration of sugar in an external solution is lower than the internal, water moves in, and the solution is said to be hypotonic to the cell
48
What is Active Transport?
-> the movement of particles from an area of lower concentration to an area of higher concentration, i.e againts the concentration gradient
-this requires energy from respiration as it is working against the gradient, which is why it is called active
49
What is photosynthesis?
-> the process of making glucose from sunlight in the leaves of the plant
-endothermic rxn (light energy is converted into chemical energy within the chloroplasts)
carbon dioxide + water ->(light) glucose + oxygen - 666
50
How does temperature affect photosynthesis?
-increase in temp = higher light intensity, rate of photosynthesis increases
-as the rxn is controlled by enzymes, this trend only continues up to a certain temp until the enzymes begin to denature and the rate of rxn decreases
51
How does light intensity affect photosynthesis?
-higher light intensity = rate of photosynthesis increases
-as the distance between the light source and the plant increases, the light intensity decreases
-light intensity is inversely 1/distance^2
52
How does carbon dioxide concentration affect photosynthesis?
-carbon dioxide is also needed to make glucose
-concentration increase = rate of rxn increases
53
Waxy cuticle:
Helps reduce water loss by evaporation and is a protective layer found at the top of the leaf
54
Upper epidermis:
Very thin and transparent in order to let light into the palisade mesophyll
55
Palisade mesopyhll:
Contain lots of chloroplasts so that photosynthesis can happen rapidly
56
Spongy mesophyll:
Have lots of air spacws to allow gases to diffuse in and out of cells faster
57
Lower epidermis:
Contains guard cells and stomata (gaps)
58
Guard cell:
Kidney-shaped cells that open and close the stomata by absorbing or losing water
-when lots of water is available, the cell fills and open stomata
59
Stomata:
Where gas exchange and loss of water by evaporation takes place-opens during the day and closes at night
60
Carbohydrates: source and function
-Bread, cereals, pasta, rice, potatoes
-a high energy source
61
Proteins: source and function
-meat, fish
- needed for growth and repair of tissue
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Lipids: source and function
-butter, oily fish
-provide energy, acts as an energy store and provide insulation
63
Dietary fibre: source and function
-fruit, wholemealbread
-aids the movement of food through the gut
64
Vitamin A: source and function
-liver
-help to improve vision and keep your hair and skin healthy
65
Vitamin C: source and function
-fruits
-needed to prevent scurvy
66
Vitamin D: source and function
-eggs
-helps to absorb calcium
67
Calcium: source and function
-milk, cheese
-needed to make bones and teeth
68
Iron: source and function
-red meat
-needed to make haemoglobin for healthy food
69
Water: source and function
-food and drink
-needed for cell reactions to take place
70
How does age affect energy requirements?
-children and teenagers need more energy than older people -they need energy to grow as they're generally more active
71
How does activity levels affect energy requirements?
-If you are more active then you will need more energy for movement
72
How does pregnancy affect energy requirements?
-pregnant women need more energy than other women- they've got to provide the energy their babies need to develop
73
What is the human alimentary canal?
the passage food moves through once it has been eaten
74
Mouth:
-Mechanical digestion: teeth break up large food pieces into smaller pieces (food bolus)
-Salivary glands produce saliva to lubricate the food bolus so it can be swallowed easily
75
Oesophagus:
-Tube from the mouth to the stomach
-Food bolus moves down due to undirectional wave-like contractions (peristalsis) created by circular muscles and longitudinal muscles that create a squeezing action
76
Pancreas:
-Produces amylase, protease and lipase enzymes
-Secretes (releases) enzymes into the stomach and small intestine
77
Stomach:
Gastric juice is released from stomach lining when it detects food in the stomach, made of:
pepsin: enzyme breaking down proteins
hydrochloric acid: makes stomach acid in order for pepsin to work and kill any ingested bacteria
-peristalsis also occurs
-the digested food is now called chyme
78
Duodenum: (small intestine)
-The first part of the small intestine
-maltase, proteases and lipases digest food here
-Bile is produced in the liver and stored in the gallbladder, its roles:
1) It is alkaline that neutralises the h.a which comes from the stomach, the enzymes in the small intestine have a higher pH than the stomach
2) It emulsifies fats, the larger surface area allows lipase to chemically break down the lipid into glycerol and fatty acids faster
79
Ileum: (small intestine)
-Lined with vili to maximise absorption of digested soluble molecules into blood
-Vili have a thin lining, a large network of capillaries and have a large surface area
80
Large Intestine:
-Water is absorbed here, to produce faeces
-Faeces is stored in the rectum and the removed though the anus
81
Carbohydrates (starch): digestive enzymes
-Broken down by carbohydrases
-Starch -> maltose by amylase
-Maltose -> glucose by maltase
82
Proteins: digestive enzymes
-Broken down by protease in the stomach and small intestine
-Proteins -> amino acids
83
Lipids: digestive enzymes
-Broken down by lipases
-Lipids -> glycerol + 3 fatty acids
84
What is respiration?
-> occurs in every cell in the body of all living things to supply ATP to cells
-cellular respiration is an exothermic rxn
85
Aerobic respiration:
-This uses oxygen
-It yields most energy
-Most occur in the mitochondria
glucose + oxygen -> carbon dioxide + water
86
Anaerobic respiration
-Occurs when there is not enough oxygen
-It does not yield as much energy
-It is only used as a last resort
-The oxidation of glucose is complete
In animals : glucose -> lactic acid
In plants + yeast (fermentation): glucose -> ethanol + carbon dioxide
87
Ribs:
Bone 'cage' surrounding the lungs to provide protection of internal organs
88
Intercostal muscle:
Muscles found between the ribs that control inhalation and exhalation
89
Diaphragm:
Muscular dome at the bottom of the thorax that changes the pressure in order to control inhalation and exhalation
90
Trachea:
The windpipe, where air enters the thorax and flows to the lungs
91
Bronchi:
The trachea divides into 2 bronchi-one to each lung
92
Bronchioles:
The bronchi further divide into smaller tubes that terminate into alveoli
93
Alveoli:
Tiny air sacs that carry out gas exchange
94
Pleural membrames:
Covers the lungs, reduces friction and keeps the lungs moist
95
Intercostal muscles in ventilation:
Inhalation: Contract
Exhalation: Relax
96
Ribcage in ventilation:
Inhalation: Up and out
Exhalation: Down and in
97
Diaphragm in ventilation:
Inhalation: Contracts downwards
Exhalation: Relaxes upwards
98
Pressure in ventilation:
Inhalation: Decreases
Exhalation: Increases
99
Air movement in ventilation:
Inhalation: Moves in
Exhalation: Moves out
100
What happens in ventilation?
the air moves through the passages because of pressure gradients that are produced by contraction of the diaphragm and thoracic muscles
101
Alveoli adaptations:
-thin walls -> one cell thick so there is a shrter distance of diffusion
-enormous surface area
-moist walls -> gases can dissolve
-great blood supply -> mantain a high concentration gradient
- permeable walls -> gases can diffuse across easily
102
Composition of the blood:
-Plasma
-Red blood cells
-White blood cells
103
Plasma:
-the liquids which carries the components in the blood
-important for the transport of carbon dioxide, digested food, urea, hormones...
104
Red blood cells:
-Carry oxygen molecules from the lungs to all the cells in the body
-Contain haemoglobin
-No nucleus: to create more space for haemoglobin
-Biconcave shape: to maximise surface area for oxygen to be absorbed
-Flexible: so they can fit through very narrow blood vessels
105
White blood cells:
-they are part of the immune system, which is the body's defence against pathogens
-there are 3 types of WBCs:
1) Phagocytic white blood cells
2) Producing anitobodies (lymphocytes)
3) Producing antitoxins
106
Phagocytic white blood cells:
-one type of white blood cell can do a process called phagocytosis, where the pathogen is engulfed and killed
-as they are able to do this with any type of pathogen it is a non-specific function
107
Producing antibodies (lymphocytes):
-each pathogen has an antigen on their surface
-once anitbodies begin to bind to the pathogen, the pathogens start to clump together resulting in it being easier for white blood cells to find them
-if you become infected again with the same pathogen, the specific complementary antibodies will be. produced at a faster rate. The invidual will not feel the symptoms of the illness. They are said to be immune
108
Producing antitoxins:
-WBCs neutralise the toxins released by the pathogen by binding to them
109
The circulatory system:
carries oxygen + nutrients to every cell in the body and removes the waste products
110
System 1 of the heart:
Deoxygentaed blood flows into the right atrium and then into the right ventricle which pumps it to the lungs to undergo gaseous exchange
111
System 2 of the heart:
Oxygenated blood flows into the left atrium and then into the left ventricle which pumps oxygenated blood around the body
112
Structure of the heart:
-Muscular walls to provide a strong heartbeat
-The muscular wall of the left ventricle is thicker because blood needs to be pumped all around the body rather than just to the lung like the right ventricle
-4 chambers that seperate the oxygenated blood from the deoxygenated blood: 2 atria above and 2 ventricles below
-valves to make sure blood does not flow backwards
-coronary arteries cover the heart to provide its own oxygenated blood supply
113
Process of the heart:
1. Blood flows into the right atrium through the vena cava, and left atrium though the pulmonary vein
2. The atria contract forcing the blood into the ventricles
3. The ventricles then contract, pushing the blood in the right ventricle into the pulmonary artery to be taken to the lungs, and blood in the left ventricle to the aorta to be taken around the body
4. As this happens, valves close to make sure the blood does not flow backwards
114
Structure of blood vessels:
-Arteries
-Veins
-Capillaries
115
Arteries:
-> carry blood AWAY from the heart
-layers of muscle in the walls make them strong
-elastic fibres allow them to stretch
-helps to prevent the vessels withstand the high pressure created by the pumping of the heart
116
Veins:
-> carry blood TOWARDS the heart
-the lumen is wide to allow the low pressure blood to flow through
-they have valves to ensure the blood flows in the right direction
117
Capillaries:
-> allow the blood to flow very close to cells to enable substances to move between them
-one cell thick walls create a short diffusion pathway
-permeable walls so substances can move across them
