4th Form Exams Flashcards
1
Q
What is a monosaccharide, disaccharide and a polysaccharide + an example of each?
A
Monosaccharide - single sugar - glucose
Disaccharide - two sugar molecules linked - maltose
Polysaccharide - many sugar molecules linked - starch
2
Q
What is a carbohydrate made up of?
A
Carbon, hydrogen, oxygen
3
Q
What is a protein molecule made up of?
A
Carbon, hydrogen, oxygen, nitrogen
4
Q
What are lipids made out of?
A
Carbon, hydrogen, oxygen
5
Q
What is the chemical test for starch, and what colours does it turn from and to?
A
Iodine
Yellow -> blue/black
6
Q
What is the chemical test for glucose, and what colours does it turn from and to?
A
Benedict’s (heat in a water bath!!)
Blue -> brick red
7
Q
What is the test for protein and what colour does it turn from and to?
A
Buiret
Blue -> purple
8
Q
What is the chemical test for lipids and what colours does it turn from and to?
A
Ethanol
Clear -> milky white emulsion
9
Q
What does amylase turn starch into?
A
Maltose
10
Q
What does protease turn protein into?
A
Amino acids
11
Q
What does lipase turn lipids into?
A
Glycerol + fatty acids
12
Q
What do plants store carbohydrates as?
A
Starch or sucrose
13
Q
What is plants cell wall made out of?
A
Cellulose
14
Q
What do animals store carbohydrates as?
A
Glycogen
15
Q
Can fungi carry out photosynthesis?
A
No
16
Q
What is fungi’s body usually organised into?
A
Mycelium, made from thread like structures (hyphae)
17
Q
What are fungi cell walls made out of?
A
Chitin
18
Q
What is saprotrophic nutrition?
A
Extra cellular secretion of digestive enzymes onto food material, absorption of the organic products
19
Q
How do fungi store carbohydrates?
A
Glycogen
20
Q
What are the cells like in protoctists?
A
They are single celled, some have features like an animal cell while others have chloroplasts
21
Q
What is the structure of bacteria?
A
- single celled
- cell wall, cell membrane, cytoplasm and plasmids
- no nucleus but a circular chromosome of DNA
22
Q
What is DNA?
A
- A biological molecule
- it is a polymer
- it is made up of many nucleotides
23
Q
What is a complementary base with thymine?
A
Adenine
24
Q
What is a complimentary base with cytosine?
A
Guanine
25
What is a pathogen and what can they be?
- A microorganism that causes disease
- fungi, bacteria, protoctists or viruses
26
What is the structure of viruses?
- not living
- can only reproduce inside living cells
- no cellular structure
27
What is an ecosystem?
A group of living organisms and their environment
28
What is a community?
All of the different species of organisms in an ecosystem
29
What is the population?
All the individuals of one species of an organism
30
What is an abiotic factor + examples?
Non - living factors
- sunlight, temperature …
31
What is a biotic factor + examples?
A living factor
- Competition, predation
32
Why does not all of the energy get transferred?
- not all of the light hits the plant, is the right wavelength, or is absorbed
- the full organism might not be eaten
- used up in respiration, digestion and movement
33
How much energy gets transferred between each tropic level?
10%
34
Equation to calculate percentage loss of energy?
(Energy transferred to next level / energy received during transfer) x 100
35
What is decomposition?
- Done by fungi and bacteria
- break down organic matter by saprotrophic nutrition
- they respire and release CO2 back into the atmosphere
36
What process does nitrogen fixing bacteria do?
Nitrogen fixation
37
What process does nitrifying bacteria do?
Nitrification
38
What causes the process of decomposition?
Decomposers
39
What process is caused by denitrifying bacteria?
Denitrification
40
What are some examples of legumes?
Peas, beans and clovers
41
What bacteria live on root nodules of legumes?
Nitrogen fixing bacteria
42
What is sexual reproduction?
The fusion of a male and female gamete to form a zygote
43
What type of cell division is asexual reproduction?
Mitosis (1 parent cell)
44
What is the male and female part of a flower?
Male - stamen
Female - egg cell
45
What is the male gamete and where is it produced?
Pollen, in the anther of the stamen
46
What is the female gamete called and where is it produced in a plant?
Ovum, ovary in the carpal
47
What is pollination?
Transfer of pollen grains from the male part of the flower to the female part of the flower
48
What stimulates the pollen tube to grow?
When the pollen lands on the stigma
49
What is seed dispersal and why is it important?
- It is the spread of seeds away from the parent plant
- it avoids competing with one another for the same resources
50
What is germination?
When the seed coat splits and the root and shoot appear
51
What three resources are needed for germination and why?
Water - softens the tester and activates the enzymes
Oxygen - aerobic respiration
Warmth - optimum temperature for enzyme reactions
52
How many chromosomes and pairs are there in a human body?
46 - 23 pairs
53
What are homologous pairs?
The same pairs of chromosomes
54
What are examples of mitosis?
- asexual reproduction
- growth
- repair
- cloning
55
What is the purpose of meiosis?
To produce gametes
56
How many cell divisions happen in mitosis and meiosis?
Mitosis - 1
Meiosis - 2
57
How many daughter cells are there in meiosis and mitosis?
Meiosis - 4
Mitosis - 2
58
Does mitosis or meiosis produce genetic variation?
Meiosis
59
Where does a baby grow?
Uterus
60
Where is sperm made?
Testes
61
What is the amnion and what is the purpose of it?
It contains amniotic fluid, which protects the baby
62
What is the role of the placenta?
Allows the exchange of materials
63
What are some examples of products the embryo needs and waste products?
Needs : oxygen, glucose, vitamins
Waste : urea, carbon dioxide, alcohol
64
What is progesterone?
The hormone that maintains pregnancy
65
What are hormones?
Chemical messengers sent from the glands
66
What is FSH and where is it released?
- causes the egg to develop
- released from the pituitary gland
67
What is LH and where is it released from?
- causes ovulation
- released from the pituitary gland
68
What does oestrogen do and where is it released from?
- repairs the uterus lining
- released from ovaries
69
What does progesterone do and where is it released?
- maintains the uterus lining
- released from ovaries
70
What is diffusion?
Movement of particles from an area of high concentration to low concentration
71
What is osmosis?
The movement of free particles from an area of high water concentration to an area of low water concentration
72
Where is bile produced and stored?
Produced in the liver
Stored in the gall bladder
73
What is the role of bile?
- neutralises stomach acid
- emulsifies lipids
74
What is the word equation for anaerobic respiration in humans and plants?
Glucose -> lactic acid
75
What is the structure of the phloem?
- Sieve plates
- Cells are alive
- Companion cell
- Movement of fluids in both directions
- No lignin
76
What is the structure of the xylem?
- No end walls
- Cells are dead
- Movement of fluids in one directions
- Water and mineral ions
77
What is transpiration?
The loss of water by evaporation from the leaves
78
What do root hair cells do?
Absorb water and mineral ions
79
Where are most of the stomata found?
Lower epidermis
80
Why do stomata need to open?
To allow CO2 to diffuse in for photosynthesis
81
What will speed up water loss?
- high temperatures
- high wind
- low humidity
- high light intensity
82
What is a potometer?
A device to measure transpiration
83
What is excretion?
The removal of chemical waste
84
Why is the upper epidermis transparent?
To let more light in
85
During the daytime what is overall excreted the most?
Oxygen
86
During nighttime what is averagely excreted the most?
Carbon dioxide
87
What colour is the hydrocarbonate indicator with little and lots of CO2?
Little - purple
Lots - yellow
88
Why is it important to have aseptic conditions in a fermenter and how do they do this?
- Unwanted bacteria will use up supplies and compete with the good bacteria
- Clean with steam before and after use
89
Why is it important to add air and nutrients to the fermenter regularly?
- allows oxygen in for respiration
- amino acids for growth
- glucose for respiration
90
Word equation for anaerobic respiration in yeast?
Glucose -> ethanol + carbon dioxide
91
Why is milk pasteurised at 85-90?
To kill any harmful microorganism or those that would turn it into curds and whey
92
Why is milk homogenised?
To disperse any fat globules
93
Why is the milk cooled to 40-45?
So it can be inoculated with the starter culture of lactobacillus bacteria without being denatured by high temperatures.
94
Why is the culture incubated for multiple hours?
To allow the lactobacillus to digest the milk proteins and ferment the lactose to lactic acid
95
Why does the yoghurt become thick?
bacteria digest lactose forming lactic acid, the pH becomes acidic making the milk proteins coagulate
96
Why is the yoghurt cooled to 5 degrees and stirred?
To make it a smooth consistency and so that flavourings can be added without ruining the taste
97
What are phosphates used for?
Making DNA and cell membranes
98
What is potassium used for?
Respiration and photosynthesis
99
What is magnesium used for?
Making chlorophyll
100
What are nitrates used for?
Making protiens
101
How do you work out magnification?
Length of image/actual length
102
What is active transport?
The movement of particles from a low to high concentration against a concentration gradient
103
What is the deficiency of Vitamin C called?
Scurvy
104
What does vitamin c do?
Growth and repair of cells
105
What causes rickets?
Lack of vitamin D
106
What is vitamin D needed for?
Helps regulate calcium and phosphates in the body
107
What is the deficiency of iron called?
Anaemia
108
What is iron needed for?
Growth and development
109
How does tar irritate the lungs?
Reduce surface in the alveoli
Irritate the delicate lining on the inside of lungs and increase production in mucus
110
How does heat from cigarettes damage lungs?
- burns away cilia so it is not swept away
- mucus accumulates
- it must be coughed up regularly
- this will cause damage to alveoli
111
How does smoking affect the circulatory system?
Creates carboxyhaemoglobin
Means that oxyhaemoglobin can’t bind
112
What is emphysema?
The alveoli become weak and thin
Reduces lung surface area
Reduces elasticity of lung tissue, making breathing painful and difficult
113
Amylase -> starch ->?
Maltose ->glucose
114
Pepsin - protein ->
Polypetides
115
Trypsin - polypeptides ->
Amino acids
116
Where is amylase produced?
Pancreas
117
Where is trypsin produced?
Pancreas
118
Where is lipase produced?
Pancreas
119
Where do amylase and trypsin work?
Duodenum
120
Where is maltase made?
Ileum wall
121
Where does lipase work?
Small intestine
122
What are proteases?
Enzymes that break down proteins
123
What is the optimum pH of pepsin?
2
124
What is the optimum pH of trypsin?
7
125
What can a lack of calcium lead to?
Osteoporosis
