AQA A Level Biology Paper 1 Questions And Answers
Mitosis acronym
Cell grows and carrys out its normal function
Interphase
Cells grow to normal size. Organelles replicate and genes are expressed to make
proteins needed.
Interphase G1
DNA and histones replicated.
Interphase S
Spindle fibres are made
Interphase G2
1. DNA winds up making chromosones from chromatin.
2. Centrioles appear at opposite poles of the cell. 3. Nucleolus disappears
Prophase (3)
1. Nuclear envelope disappears.
2. Chromosomes align along the equator of the cell.
3. Spindle fibres connect centrioles to chromosomes
Metaphase (3)
1. Microtubules contract pulling daughter chromosomes to opposite poles of the
cell.
Anaphase (1)
1. Spindle fibres disperse.
,2. Nuclear envelope forms.
3. Chromatids uncoil to chromatin
Telophase (3)
1. Cytoplasm constricts separating the cells into two.
2. Membrane forms creating two new genetically identical daughter cells.
Cytokinesis (2) number of cells in mitosis/total number of cells
Mitotic index
1. Circular DNA replicates and both copies attach to the cell membrane.
2. Plasmids also replicate.
Binary fission 1 (2)
Cell membrane grows between the two DNA molecules and pinches them inwards
dividing the cell into 2.
Binary Fission 2 (1)
1. Cell wall forms, dividing the two genetically identical daughter cells.
2. Same circular DNA.
Binary Fission 3
1. Attach to host cell via attachment protein and inject nucleic acid into the cell.
2. This gives the instructions to construct the virus
Virus Replication 1 (2)
1. The virus is then assembled and leaves the cell, taking the phospholipid bilayer
with it.
2. This creates holes in the cell and kills it.
Virus Replication 2 (2)
Fluid: All the components can move around. Mosaic: Many different components
all fit together
, Fluid mosaic Structure [Fluid][Mosaic] (2)
The passive movement of particles from a high concentration to a region of low
concentration, down a concentration gradient.
Diffusion
The passive transport of large molecules such as amino acids and sugars, but they
require integral proteins to pass through.
Facilitated Diffusion
Small, non-polar molecules (excluding water) freely diffuses in and out of cells
through gaps between phospholipids.
Simple Lipid Diffusion
The passive movement of water molecules across a partially permeable
membrane from a high water potential to a low water potential, down a
concentration gradient. (Distilled water = 0Ψ)
Osmosis
Equal concentration solution to the cell
Isotonic
Solution of higher concentration to cell.
Hypertonic
Solution of a lower concentration to cell.
Hypotonic
The movement of substances across a cell membrane through a carrier protein
against a concentration gradient, from a high to low concentration with the
expenditure of ATP.
Active transport
Mitosis acronym
Cell grows and carrys out its normal function
Interphase
Cells grow to normal size. Organelles replicate and genes are expressed to make
proteins needed.
Interphase G1
DNA and histones replicated.
Interphase S
Spindle fibres are made
Interphase G2
1. DNA winds up making chromosones from chromatin.
2. Centrioles appear at opposite poles of the cell. 3. Nucleolus disappears
Prophase (3)
1. Nuclear envelope disappears.
2. Chromosomes align along the equator of the cell.
3. Spindle fibres connect centrioles to chromosomes
Metaphase (3)
1. Microtubules contract pulling daughter chromosomes to opposite poles of the
cell.
Anaphase (1)
1. Spindle fibres disperse.
,2. Nuclear envelope forms.
3. Chromatids uncoil to chromatin
Telophase (3)
1. Cytoplasm constricts separating the cells into two.
2. Membrane forms creating two new genetically identical daughter cells.
Cytokinesis (2) number of cells in mitosis/total number of cells
Mitotic index
1. Circular DNA replicates and both copies attach to the cell membrane.
2. Plasmids also replicate.
Binary fission 1 (2)
Cell membrane grows between the two DNA molecules and pinches them inwards
dividing the cell into 2.
Binary Fission 2 (1)
1. Cell wall forms, dividing the two genetically identical daughter cells.
2. Same circular DNA.
Binary Fission 3
1. Attach to host cell via attachment protein and inject nucleic acid into the cell.
2. This gives the instructions to construct the virus
Virus Replication 1 (2)
1. The virus is then assembled and leaves the cell, taking the phospholipid bilayer
with it.
2. This creates holes in the cell and kills it.
Virus Replication 2 (2)
Fluid: All the components can move around. Mosaic: Many different components
all fit together
, Fluid mosaic Structure [Fluid][Mosaic] (2)
The passive movement of particles from a high concentration to a region of low
concentration, down a concentration gradient.
Diffusion
The passive transport of large molecules such as amino acids and sugars, but they
require integral proteins to pass through.
Facilitated Diffusion
Small, non-polar molecules (excluding water) freely diffuses in and out of cells
through gaps between phospholipids.
Simple Lipid Diffusion
The passive movement of water molecules across a partially permeable
membrane from a high water potential to a low water potential, down a
concentration gradient. (Distilled water = 0Ψ)
Osmosis
Equal concentration solution to the cell
Isotonic
Solution of higher concentration to cell.
Hypertonic
Solution of a lower concentration to cell.
Hypotonic
The movement of substances across a cell membrane through a carrier protein
against a concentration gradient, from a high to low concentration with the
expenditure of ATP.
Active transport
