1|Page
AQA BIOLOGY PAPER 1 QUESTIONS AND ANSWERS FOR
EXAM PREPARATION
EXACT AND ACCURATE LATEST EXAM VERSION TEST BANK
Differences between light microscope and electron microscope
Light: are cheap to make and they allow you to see the outline of cells
Electron: Very expensive, however you can visualise finer details (including sub-cellular structures) due to
higher resolution and greater resolving power
Equation for magnification
Magnification = image size / real size
Differences between Eukaryotic and prokaryotic cells
Eukaryotes have a nucleus in which their DNA is found and prokaryotic cells have no nucleus or DNA
(Plant and Animal cells)
Prokaryotes don't have a nucleus and their DNA is in loops call plasmids (Bacteria)
what does a cell membrane do and what is it
semi-permeable, controls what enters and leaves
what does a cell wall do and what is it
made of cellulose, providing rigid structure
what is cytoplasm and what happens in it
liquid that makes up the cell, where most chemical reactions take place
What does the mitochondria do?
where respiration takes place, releasing energy for the cell to function
what does chloroplasts do
contain green pigment chlorophyll, where photosynthesis takes place
what does ribosomes do
synthesises proteins
What does the vacuole do?
where cell sap and minerals are stored
difference between diploid and haploid
,2|Page
diploid: 23 pairs of chromosomes, 46 (human cells)
haploid: just 23 chromosomes, gametes (sperm/eggs)
what is mitosis
division of cells for growth and repair
process of mitosis
1. nucleus dissolves, genetic material is duplicated
2. two sets of chromosomes more to different sides
3. mitochondria and other organelles are duplicated
4. the cell divides producing two genetically identical diploid cells (new nuclei are formed in each)
What can stem cells do and where are they found
can specialise to perform specific functions.
found in human and animal embryos and plant meristems
what can stem cells in bone marrow be specialised into
only specialise into blood cells
advantages of stem cells
treat a wide range of diseases
disadvantages of stem cells
rejection by the body's immune system
cells can mutate e.g can turn into cancer cells
what can embryonic stem cells do
can develop into any type of body cell
ethical issues for embryonic stem cells
involves the embryo being destroyed
what's diffusion
• movement of particles from an area of high to low concentration
• down a concentration gradient
• passive: requires no energy
what's osmosis
• diffusion of water across a semi-permeable membrane
, 3|Page
• balances the concentrations of solution in and outside a cell
what increases the rate of diffusion and osmosis
temperature, surface area, difference in concentrations
osmosis practical: potatoes
• weigh and place identical cylinders from the same potato in sugar solutions of varying concentrations
• after a set time, remove excess water and reweigh
what's active transport
• movement of particles through a membrane
via CARRIER PROTEINS
• requires energy, and so can move them against the concentration gradient
body levels organisation eg. cell…
cells > tissues > organs > organ systems
process of digestion starting with (teeth stomach liver pancreas intestines)
• teeth break down food. saliva contains amylase (enzyme)
• the stomach contains hydrochloric acid and enzymes that chemically break down food
• the liver produces bile, which breaks down lipids to form droplets, increasing their surface area
• pancreas secretes amylase, breaks down starch into glucose
• water absorbed into blood by large intestine
• nutrients (like glucose) absorbed into blood by villi in the small intestine
what are enzymes
special proteins, biological catalysts
effect of temperature and pH on enzymes
rate increases until the enzyme denatures (active site changes shape), can't work at optimum rate
what's carbohydrase
breaks down large carbohydrates into simple sugars
what's protease
breaks down proteins into amino acids
what are lipases
breaks down lipids into glycerol and fatty acids
AQA BIOLOGY PAPER 1 QUESTIONS AND ANSWERS FOR
EXAM PREPARATION
EXACT AND ACCURATE LATEST EXAM VERSION TEST BANK
Differences between light microscope and electron microscope
Light: are cheap to make and they allow you to see the outline of cells
Electron: Very expensive, however you can visualise finer details (including sub-cellular structures) due to
higher resolution and greater resolving power
Equation for magnification
Magnification = image size / real size
Differences between Eukaryotic and prokaryotic cells
Eukaryotes have a nucleus in which their DNA is found and prokaryotic cells have no nucleus or DNA
(Plant and Animal cells)
Prokaryotes don't have a nucleus and their DNA is in loops call plasmids (Bacteria)
what does a cell membrane do and what is it
semi-permeable, controls what enters and leaves
what does a cell wall do and what is it
made of cellulose, providing rigid structure
what is cytoplasm and what happens in it
liquid that makes up the cell, where most chemical reactions take place
What does the mitochondria do?
where respiration takes place, releasing energy for the cell to function
what does chloroplasts do
contain green pigment chlorophyll, where photosynthesis takes place
what does ribosomes do
synthesises proteins
What does the vacuole do?
where cell sap and minerals are stored
difference between diploid and haploid
,2|Page
diploid: 23 pairs of chromosomes, 46 (human cells)
haploid: just 23 chromosomes, gametes (sperm/eggs)
what is mitosis
division of cells for growth and repair
process of mitosis
1. nucleus dissolves, genetic material is duplicated
2. two sets of chromosomes more to different sides
3. mitochondria and other organelles are duplicated
4. the cell divides producing two genetically identical diploid cells (new nuclei are formed in each)
What can stem cells do and where are they found
can specialise to perform specific functions.
found in human and animal embryos and plant meristems
what can stem cells in bone marrow be specialised into
only specialise into blood cells
advantages of stem cells
treat a wide range of diseases
disadvantages of stem cells
rejection by the body's immune system
cells can mutate e.g can turn into cancer cells
what can embryonic stem cells do
can develop into any type of body cell
ethical issues for embryonic stem cells
involves the embryo being destroyed
what's diffusion
• movement of particles from an area of high to low concentration
• down a concentration gradient
• passive: requires no energy
what's osmosis
• diffusion of water across a semi-permeable membrane
, 3|Page
• balances the concentrations of solution in and outside a cell
what increases the rate of diffusion and osmosis
temperature, surface area, difference in concentrations
osmosis practical: potatoes
• weigh and place identical cylinders from the same potato in sugar solutions of varying concentrations
• after a set time, remove excess water and reweigh
what's active transport
• movement of particles through a membrane
via CARRIER PROTEINS
• requires energy, and so can move them against the concentration gradient
body levels organisation eg. cell…
cells > tissues > organs > organ systems
process of digestion starting with (teeth stomach liver pancreas intestines)
• teeth break down food. saliva contains amylase (enzyme)
• the stomach contains hydrochloric acid and enzymes that chemically break down food
• the liver produces bile, which breaks down lipids to form droplets, increasing their surface area
• pancreas secretes amylase, breaks down starch into glucose
• water absorbed into blood by large intestine
• nutrients (like glucose) absorbed into blood by villi in the small intestine
what are enzymes
special proteins, biological catalysts
effect of temperature and pH on enzymes
rate increases until the enzyme denatures (active site changes shape), can't work at optimum rate
what's carbohydrase
breaks down large carbohydrates into simple sugars
what's protease
breaks down proteins into amino acids
what are lipases
breaks down lipids into glycerol and fatty acids
