PATHWAYS REVION BIOLOGY Flashcards
1
Q
What is the function of the nucleus
A
contains genetic information and controls the functions of the cell
2
Q
What is the function of the cell membrane
A
controls what enters and leaves the cell
3
Q
What is the function of the cytoplasm
A
where many cell activities and chemical reactions take place
4
Q
What is the function of the mitochondria
A
site of aerobic repiration
5
Q
What is the function of the ribosome
A
site of protien synthesis
6
Q
What is the function of a chloroplast
A
where photosynthesis occurs
7
Q
What is the function of the vacuole
A
stores water and chemicals such as cell sap
8
Q
What is the function of the cell wall
A
strengthens and supports the cell
9
Q
what is a dna loop
A
a loop of dna not enclosed within a nucleus
10
Q
What is plasmid DNA
A
small circle of dna, may contain genes associated with antibiotic resistance
11
Q
which 3 organelles are found in plant cells but not in animal cells
A
chloroplast, vacuole,cell wall
12
Q
which 2 organelles are exclusive to bacterial cells
A
dna loop, plasmid dna
13
Q
how is a sperm cell adapted to its function
A
lots of mitochondria, has a flagellum
14
Q
how is a nerve cell adapted to its function
A
long to transmit electrical signals over a distance
15
Q
how is a muscle cell adapted to its function
A
protien fibres that can contract
16
Q
how is a root hair cell adapted to its function
A
large surface area to volume ratio, thin cell wall
17
Q
how is a xylem cell adapted to its function
A
waterproof cell wall, cells are hollow to allow water to move through
18
Q
how is a phloem cell adapted to its function
A
some cells have:
lots of mitochondria for active transport, very little cytoplasm so that sugars can move through easily
19
Q
what is the formula that links magnification image size and actual size
A
I
—- (I am)
AxM
20
Q
what is the resolution of a microscope
A
the ability of a microscope to distinguish detail
21
Q
what is magnification
A
the degree by which an object is enlarged
22
Q
name the different —–metres in oder of size from largest to smallest
A
centimeter, millimeter, micrometer, nanometre
(centi-milli-micro-nanno)
23
Q
describe how to make an onion slide
A
- Cut open an onion.
- Use forceps to peel a thin layer of epidermis from
the inside. - Lay the layer of epidermis on a microscope slide.
- Add a drop of iodine solution to the layer.
- Carefully place a coverslip over the layer.
- Observe it under a microscope to see onion cells.
24
Q
define diffusion
A
the net movement of particles from an area of high concentration to an area of low concentration
25
define osmosis
the net movement of water particles across a semi permeable membrane down the concentration gradient from an area of high concentration to low concentration. From a dilute solution to a concentrated solution.
26
define active transport
the movement of substances against the concentration, from an area of low concentration to high concentration. `it requires energy from respiration.
27
name 3 factors that affect diffusion
temperature, surface area of membrane they have to move across, the differences in the concentration gradients it moves from/to
28
what does an artery do
transports blood away from the heart
29
what is an adaptation of an artery
thick wall to withstand pressure
30
what does vein do
takes blood back to the heart
31
what is an adaptation of veins
has valves to prevent back flow of blood
32
what does a capillary do
exchange of substances between blood and cells
33
what is an adaptation of a capillary
one cell thick for quick diffusion of substances
34
define transpiration
the loss of water vapour from the leaves by evaporation from cells then out through the stomata
35
what is the transpiration stream
the movement of water from the roots up the stem to the leaves
36
define translocation
the movement of dissolved sugars around the plant
37
a name 4 factors that effect transpiration rates
temperature-increases the rate as the water evaporates quicker
humidity-decreases as the water evaporates slowly
wind speed- increasing wind speed increases the rate as water evaporates quicker
light- increasing light increases the rate as the stomata open more
38
what is the purpose of guard cells
they open the stomata in plants to allow gas exchange or close to prevent water loss
39
what is an adaptation of the epidermis in plants?
it is transparent to allow sunlight through to the cells below for photosynthesis
40
what do palisade mesophyll cells do
where most photosynthesis takes place. They have many chloroplasts to do so
41
What does the spongy mesophyll cells do
some photosyntheses, has air spaces for diffusion of oxygen and carbon dioxide.
42
what are the stomata
openings in the bottoms of leaves that allow oxygen and carbon dioxide to diffuse in and out of the plant
43
define cells
the basic building blocks that make up all living things
44
define tissue
a group of similar cells that work together to carry out a function
45
define organ
a group of different tissues that work together to perform a function
46
defin organ system
a group of organs that work together to perform a certain function
47
define multicellular organism
an organism made up of different organ systems
48
what is cell differenciation
the process in which cells become specialised to carry out s specific job
49
what is the role of the mouth in digestion
where digestion begins, enzymes released from the salivary glands break down starch into soluble sugars
50
what is the role of thestomach in digestion
one of the main organs where food is digested. It contains hydroclauric acid, which along with enzymes helps to break down food.
51
what is the role of the small intestine in digestion
starch and protien are further broken down by enzymes and lipids begin to be broken down.
52
how is the small intestine adapted for the absorption of nutrients
its has many microvilli and villi which are finger like projections which have thin cell walls for diffusion, mitochondria for active transport and give the intestine a very high surface area also for diffusion
53
what is the role of the liver in digestion
makes bile which released into the small intestine to aid in the digestion of lipids. It is also alkali and neutralises the acid from the stomach
54
what is the role of the large intestine in digestion
where water is absorbed from undigested food. forms faces.
55
what is an enzyme
a biological catalyst which speeds ip the rate of reactions without being used up.
56
define substrate in the context of enzymes
the chemical that fits into the active site of an enzyme
57
define denatured
when the active site of an enzyme deforms and the substrate can no longer fit in. Can be caused by temprature or PH
58
what does amylase break down
starch
59
where is amylase made
the salivary glands, the pancreas, the small intestine
60
what does lipase break down
fats
61
where is lipase made
the small intestine, the pancreas
62
what does protease break down
protiens
63
where is protease made
stomach, pancreas, small intestine
64
what is stored in the gallbladder
bile
65
what is the food test for starch
add iodine , if starch is present it will go from orange/brown to lue/black
66
what is the food test for protein
blue buret turns purple for proteins.
67
what is the food test for glucose
add blue Benedict's solution. Place in a hot water bath. If sugars are present it will go:
green for a little
yellow, orange
brick red for a lot
68
what is the food test for lipids
add ethanol and decant into water. If positive it will go cloudy white
69
what is the word equation for photosynthesis
carbon dioxide + water ------> glucose + oxygen
70
what is the symbol equation for photosynthesis
6CO2+6H2O→C6H12O6+6O2
71
why doesn't photosynthesis happen in the dark
there is no light energy from the sun to power the reaction
72
how does carbon dioxide enter the plant for photosynthesis?
through the stomata
73
how is some of the oxygen produced by the plant used
in respiration
74
how does excess oxygen escape the plant
through the stomata
75
what are some uses of glucose in plants?
produces cellulose ( makes the cell wall in cells)
makes amino acids to make protiens
converted into lipids for energy in seeds
converted into starch, an energy store in cells
76
why are leaves greeen
they contain chlorophyll, a green pigment which helps absorb sunlight
77
why are leaves wide
to help absorb the maximum amount of sunlight
78
what temperature do the enzymes needed for photosynthesis denature?
45 degrees C
78
what are veins in plants
they consist of xylem and phloem and transport water and sugars around the plant
79
what is a sign of magnesium deficiency in plants?
lower leaves turning yellow, starting at the bottom of the plant
80
what is a sign of nitrogen deficiency in plants
weak stems and poor growth
81
what is a use of magnesium in plants
used to make chlorophyll
82
what is a use of nitrogen in plants
used to make proteins which helps to make leaves
83
how do you investigate the rate of photosynthesis as a practical?
investigate the rate of photosynthesis under different light intensities. Submerge a piece of pondweed in water, place a lamp at varying distances and count the number of bubbles produced over a set period.
84
how are greenhouses useful for growing plants?
made of glass to trap heat
84
what is an independent variable
what you change
84
what is a control variable
what you keep the same
85
what is a dependant variable
what you measure
86
who can farmers provide lots of light to their plants when the sun isnt out
use of artificial light is prominent to give plants more time for photosynthesis
87
how are paraffin heaters useful for growing plants
they burn Fuels which releases heat, and also produces carbo dioxide which helps maximise photosynthesis
88
what is respiration
a chemical reaction that releases energy
89
is respiration endothermic or exothermic?
exothermic because it releases energy
90
what is the word equation for AEROBIC respiration
glucose+oxygen----->carbon dioxide+water
91
why does the body go into using anaerobic respiration?
is there Is little/ no oxygen available for aerobic respiration
92
what is the word equation for ANAEROBIC respiration
glucose---->lactic acid
93
what is anaerobic respiration referred to in yeast and bacteria
fermentation
94
what is the word equation for fermentation
glucose--->carbon dioxide+ethanol+energy
95
what are some uses of fermentation
carbon dioxide and ethanol useful in brewing alcohol
carbon dioxide causes bread to rise
96
what is oxygen debt?
when lactic acid builds up in the body due to anaerobic respiration, oxygen is needed to break it down
97
define metabolism
the sum of all the chemical reactions that go on inside an organism's body or cell
