Biology Paper 1 Flashcards
1
Q
What do microscopes allow us to do?
A
Magnify
2
Q
What are light microscopes?
A
Light microscopes have a limited magnification and resolution
3
Q
What are electron microscopes?
A
Electron microscopes have a greater magnification and resolution
4
Q
What is the equation for magnification?
A
Magnification=image size/real size
5
Q
How do we calculate total magnification?
A
Total magnification= magnification of eyepiece lens x magnification of objective lens
6
Q
What are eukaryotes and prokaryotes?
A
Eukaryotes have their genetic material inside of a nucleus (animal and plant cells), Prokaryotes have their genetic material outside of a nucleus (bacterial cells)
7
Q
What is the difference between eukaryotes and prokaryotes?
A
Prokaryotes are a lot smaller than eukaryotes
8
Q
What is the function of the nucleus?
A
Contains the genetic material (DNA)
9
Q
What is the function of the cytoplasm?
A
Where chemical reactions take place
10
Q
What is the function of the cell membrane?
A
Controls what can leave and enter the cell
11
Q
What is the function of the mitochondria?
A
Where aerobic respiration takes place
12
Q
What is the function of the ribosomes?
A
Site of protein synthesis
13
Q
What are 3 features that plant cells have that animal cells don’t?
A
Chloroplasts, cell wall and a vacuole
14
Q
What is the function of the chloroplasts?
A
Contains chlorophyll- site of photosynthesis
15
Q
What is the function of the cell wall?
A
Contains cellulose which strengthens and supports the cell
16
Q
What is the function of the vacuole?
A
Contains cell sap which gives the plant cell its shape
17
Q
What is the function of the sperm cell?
A
To swim to the egg cell, we call this fertilisation
18
Q
What happens during fertilisation?
A
Genetic material of the egg cell and sperm cell combine
19
Q
How are sperm cells adapted for their function?
A
They have a long tail to help them swim
20
Q
Why are sperm cells packed full of mitochondria?
A
To provide energy for swimming
21
Q
Why do sperm cells contain enzymes?
A
To digest their way through the outer layer of the egg cell
22
Q
What is the job of a nerve cell?
A
To send electrical impulses around the body
23
Q
What is the function of the axon?
A
Carries electrical impulses from one part of the body to another
24
Q
What is the function of the myelin?
A
Insulates the axon and speeds up the transmission of nerves and impluses
25
What is the function of the synapses?
Junctions which allow the impulse to pass from one nerve to another
26
Why do muscles contain protein fibre?
To help muscles contract
27
What is the function of the muscle cells?
To contract and perform movement
28
How are muscle cells adapted for their function?
They have lots of mitochondria which provide energy for moving
29
What is the function of the root hair cell?
Absorb water and minerals from the soil
30
How are root hair cells adapted for their function?
They have a large surface area to absorb water and minerals more quickly
31
How does air get from the mouth and nose to the blood via the lungs?
When we breathe in, air travels down the trachea, the trachea then branches into two tubes called bronchi, which leads to the lungs, in the lungs these tubes split into smaller tubes called bronchioles, and on the end of the bronchioles, there is alveoli, where oxygen is diffused into the bloodstream. Carbon dioxide is a waste product, this is called gas exchange
32
3 ways the alveoli are adapted for efficient gas exchange
1) large surface area for the many tiny air sacs
2)thin walls for efficient gas exchange
3)surrounded by capillaries to increase contact between air and blood
33
What is a specialised cell?
a cell that carries out a particular function
34
What is a cell?
The basic building blocks that make up all living organisms
35
What is a tissue?
A group of similar cells that work together to carry out a particular function
36
What is an organ?
A group of different tissues that work together to perform a certain function
37
What is an organ system?
A group of organs working together to perform a particular function
38
What is osmosis?
The net movement of water particles from an area of high concentration to and area of low concentration through a partially permeable membrane
39
What is diffusion?
The net movement of particles from an area of high concentration to an area of low concentration
40
How does temperature affect the rate of diffusion?
As the temperature increases, so does the kinetic energy, so the particles can diffuse more quickly.
41
How does surface area affect the rate of diffusion?
As the surface area increases, the rate of diffusion also increases because there is more space for molecules to diffuse across the membrane
42
What is a less concentrated solution?
A solution that has a lower amount of solute dissolved in it
43
Complete the gaps in the sentence: the … the object or cell, the … the surface area:volume ratio
The larger the object or cell, the smaller the surface area to volume ratio
44
What is a concentration gradient?
A concentration gradient occurs when the concentration of particles is higher in one area than another
45
How does a concentration gradient affect the rate of diffusion?
The steeper the concentration gradient, the faster molecules will diffuse
46
What is active transport?
The net movement of particles from an area of low concentration to high concentration
47
Describe how root hair cells take in mineral ions
Root hair cells take in minerals through active transport
48
How do you calculate the surface area of a cube?
Surface area = length x width
49
How do you calculate the volume of a cube?
Volume=length x width x height
50
How do you calculate surface area:volume ratio
Surface area:volume ratio=surface area/volume
51
How are the villi adapted for diffusion?
1) single layer of surface cells
2) very good blood supply
3) thin wall for short diffusion distance
52
How are leaves adapted for efficient gas exchange?
1) large surface area
2) thin for short diffusion distance
3) many stomata
53
What is the order of organs in the digestive system?
Mouth, oesophagus, stomach, pancreas, liver, small intestine, large intestine, anus
54
What are enzymes?
Proteins that act as biological catalysts
55
How does an enzyme break down a substrate?
An enzyme breaks down a substrate through the lock and key theory, a substrate collides with the active site of an enzyme and becomes attached, the enzyme then breakdown the substrate
56
How does temperature affect enzyme activity?
Increasing temperature -> speeds up enzyme activity
57
How does pH affect enzyme activity?
pH value increases -> decreases enzyme activity
58
How do we investigate the effect of pH on enzyme activity?
Using a syringe, add amylase solution and buffer solution to a test tube, then immediately sit the test tube in a water bath and set a stop clock for 5 minutes
59
What is an independent variable?
The thing you change
60
What is a dependant variable?
The thing you measure
61
What is a control variable?
The thing you keep the same
62
What is the independent, dependant and control variable in the investigation of effect of pH on enzyme activity?
Independent= pH level
Dependant= enzyme activity
Control=amount of substrate used
63
What is the substrate and product of carbohydrase and where is it made?
Substrate=starch
Product=glucose
Made in= mouth, pancreas and small in intestine
64
What is the substrate and product of protease and where is it made?
Substrate= proteins
Product=amino acids
Made in= stomach, pancreas and small intestine
65
What is the substrate and product of lipase and where is it made?
Substrate= lipids
Product= glycerol and fatty acids
Made in= pancreas
66
What are the 2 uses of bile in digestion?
1) to carry away waste
2) to break down fats
67
What is a communicable disease?
A disease that can be spread from person to person
68
What is a non communicable disease?
A disease that cannot be spread from person to person
69
What is health?
The state of physical and mental well being
70
What is a pathogen?
A microorganism that causes disease
71
What are the 4 types of pathogens?
Bacteria, viruses, fungi, protists
72
How does bacteria make us feel ill?
Bacteria reproduces very rapidly and releases toxins which damage our tissues
73
How do viruses make us feel ill?
Viruses live and reproduce inside our cells, causing cell damage when they burst out the cell
74
How are pathogens spread?
1) air
2) water
3) direct contact
75
How can we reduce the spread of pathogens?
1) washing hands
2) providing clean drinking water
3) self isolation
4) vaccination
76
What are symptoms of measles?
Fever, skin rash
77
How is measles spread
In droplets
78
What type of pathogen are measles and HIV?
Viruses
79
What are symptoms of HIV?
flu like symptoms, damaged immune system
80
What can be used to stop HIV getting worse?
Antiretroviral drugs
81
How is HIV spread?
through sexual contact
82
How do we prevent getting HIV?
wearing protection during sexual intercourse
83
What type of pathogen are salmonella and gonorrhoea?
Bacteria
84
How is salmonella spread?
Digesting infected food
85
What are symptoms of salmonella?
Fever, stomach pain, vomiting and diarrhoea
86
How do we prevent salmonella spreading?
Vaccinating chickens
87
How is gonorrhoea spread?
Through sexual intercourse
88
What are symptoms of gonorrhoea?
Yellow/green discharge, pain when urinating
89
How do we prevent gonorrhoea?
Wearing protection
90
What type of pathogen is malaria?
Protist
91
What are symptoms of malaria?
Fever
92
How is malaria spread?
Through mosquitoes
93
How can we prevent the spread of malaria?
Stopping vectors from breeding
94
How does skin protect us?
It forms a protective layer, produces an oily substance which kills bacteria, forms scabs when skin is broken
95
How does the nose protect us?
Nose hairs trap pathogens
96
How do the lungs protect us?
They have cilia which trap pathogens
97
How does the stomach protect us?
Hydrochloric acid kills bacteria
98
What does the immune system do?
Destroy pathogens and protects us if the same bacteria tries to infect us again
99
What do white blood cells do?
Ingest and destroy pathogens
100
What do white blood cells do?
Sticks to pathogens and destroys them
101
What do antitoxins do?
Stick to toxins and prevents them from damaging cells
102
What is the function of the upper epidermis?
To let light through
103
What is the function of the waxy cuticle?
Waterproof layer
104
What if the function of the palisade layer?
Where most photosynthesis occurs
105
What is the function of the phloem?
Transports water
106
What is the function of the xylem?
Transports water and other mineral salts
107
What is the function of the spongy metoprolol layer?
Where gas exchange occurs
108
What is the function of the guard cells?
Control water loss
109
What is the function of the stomata?
Regulate gas exchange between the plant and the environment
110
What is antibiotic resistance?
When bacteria can no longer be killed by an antibiotic
111
Can antibiotics kill viruses?
No
112
What is heard immunity
When a large part of the population are vaccinated against a disease, this can reduce the chance of people coming into contact with specific pathogens
