AQA AS BIOLOGY PAPER 1 7401 MAY 2024
COMBINED QUESTIONS AND CORRECT
ANSWERS ALREADY GRADED A+
GUARANTEED PASS
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
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
- balances the concentrations of solution in and outside a cell
what increases the rate of diffusion and osmosis?
temperature, surface area, difference in concentrations
COMBINED QUESTIONS AND CORRECT
ANSWERS ALREADY GRADED A+
GUARANTEED PASS
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
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
- balances the concentrations of solution in and outside a cell
what increases the rate of diffusion and osmosis?
temperature, surface area, difference in concentrations
