AQA GCSE Biology exam For Exam ...,
Exercises of Biology
Eukaryotic cells - ANSWER-Cells with genetic material (DNA) enclosed in a nucleus, including plant and
animal cells.
Prokaryotic cells - ANSWER-Cells with genetic material (DNA) not enclosed in a nucleus, such as
bacterial cells, which are much smaller in comparison.
Genetic material in prokaryotic cells - ANSWER-A single loop of DNA that may also have small rings of
DNA called plasmids.
Order of magnitude - ANSWER-A power to the base 10 used to quantify and compare size, where 10
(10^1) times bigger equals 1 order of magnitude bigger.
Diameter of amoeba - ANSWER-10 μm = 10 x 10^-6 m.
Diameter of egg cell - ANSWER-0.1 mm = 0.1 x 10^-3 m.
Difference in orders of magnitude - ANSWER-Calculated as 5 - 4 = 1.
Diameter of liver cell - ANSWER-2.5 x 10^-5 m.
Diameter of bacterial cell - ANSWER-2.0 x 10^-7 m.
Liver cell size comparison - ANSWER-The liver cell is 125 times larger than the bacterial cell, which is
approximately 100, equating to 2 orders of magnitude larger.
Cell membrane - ANSWER-Controls movement of substances in and out of the cell.
Cytoplasm - ANSWER-Gel-like substance where chemical reactions take place.
Nucleus - ANSWER-Contains genetic material (DNA) and controls activities of the cell.
Mitochondria - ANSWER-Site of aerobic respiration that releases energy from glucose.
Ribosomes - ANSWER-Site of protein synthesis.
Cell wall - ANSWER-Made of cellulose, strengthens the cell; algal cells also have one.
Chloroplasts - ANSWER-Contain chlorophyll to absorb light for photosynthesis to make glucose.
Permanent vacuole - ANSWER-Filled with cell sap to help keep the cell turgid and support the plant.
Sub-cellular structures in animal cells - ANSWER-Include cell membrane, cytoplasm, DNA, ribosomes,
and nucleus.
Sub-cellular structures in plant cells - ANSWER-Include cell membrane, cytoplasm, DNA, ribosomes,
nucleus, mitochondria, cell wall, chloroplasts, and permanent vacuole.
, Sub-cellular structures in bacterial cells - ANSWER-Include cell membrane, cytoplasm, DNA, ribosomes,
and plasmids.
Bacterial cells - ANSWER-They have no sub-cellular structures surrounded by a membrane, eg.
nucleus, mitochondria.
Cell wall - ANSWER-Just like any other wall, the cell wall provides strength.
Cell membrane - ANSWER-What controls what moves in and out of a cell.
Red blood cell (RBC) - ANSWER-RBC has no nucleus, plant cell does.
Plant cell - ANSWER-Plant cell has a cell wall, RBC does not.
Chloroplasts - ANSWER-RBC does not contain chloroplasts or chlorophyll, plant cell does.
Permanent vacuole - ANSWER-RBC has no (permanent) vacuole, plant cell does.
Haemoglobin - ANSWER-RBC contains haemoglobin, plant cell does not.
Light microscope - ANSWER-Use a light microscope to observe, draw and label a selection of plant and
animal cells.
Microscope slide preparation - ANSWER-Peel off thin layer of tissue using forceps, place on water
drop on slide.
Stain - ANSWER-To make sub-cellular structures visible.
Thin layer of onion tissue - ANSWER-To let light pass through.
Cover slip - ANSWER-Lowered at an angle to avoid trapping air bubbles.
Total magnification calculation - ANSWER-Magnification of eyepiece lens x magnification of objective
lens eg. 10 x 4 = 40.
Field of view measurement - ANSWER-Measure diameter of field of view by using microscope to
observe a transparent ruler.
Scientific drawing rules - ANSWER-No sketching or shading - only use clear, continuous lines (with a
sharp pencil).
Magnification scale - ANSWER-Include a magnification scale (eg. x 400).
Labeling features - ANSWER-Label important features eg. nucleus.
Safety measure during cell sampling - ANSWER-Wear gloves / wash hands because stain is an irritant.
Disinfecting work surfaces - ANSWER-To prevent spread of possible infection.
Higher power objective lens - ANSWER-Use a higher power objective lens (or use an electron
microscope but a student wouldn't have access).
Sperm cell - ANSWER-Long tail / flagellum → allows sperm to swim / move towards egg.
Nerve cell - ANSWER-Long → carry electrical impulses / signals over long distances.
Muscle cell - ANSWER-Many mitochondria → ↑ rate of respiration to release energy for contraction.
Exercises of Biology
Eukaryotic cells - ANSWER-Cells with genetic material (DNA) enclosed in a nucleus, including plant and
animal cells.
Prokaryotic cells - ANSWER-Cells with genetic material (DNA) not enclosed in a nucleus, such as
bacterial cells, which are much smaller in comparison.
Genetic material in prokaryotic cells - ANSWER-A single loop of DNA that may also have small rings of
DNA called plasmids.
Order of magnitude - ANSWER-A power to the base 10 used to quantify and compare size, where 10
(10^1) times bigger equals 1 order of magnitude bigger.
Diameter of amoeba - ANSWER-10 μm = 10 x 10^-6 m.
Diameter of egg cell - ANSWER-0.1 mm = 0.1 x 10^-3 m.
Difference in orders of magnitude - ANSWER-Calculated as 5 - 4 = 1.
Diameter of liver cell - ANSWER-2.5 x 10^-5 m.
Diameter of bacterial cell - ANSWER-2.0 x 10^-7 m.
Liver cell size comparison - ANSWER-The liver cell is 125 times larger than the bacterial cell, which is
approximately 100, equating to 2 orders of magnitude larger.
Cell membrane - ANSWER-Controls movement of substances in and out of the cell.
Cytoplasm - ANSWER-Gel-like substance where chemical reactions take place.
Nucleus - ANSWER-Contains genetic material (DNA) and controls activities of the cell.
Mitochondria - ANSWER-Site of aerobic respiration that releases energy from glucose.
Ribosomes - ANSWER-Site of protein synthesis.
Cell wall - ANSWER-Made of cellulose, strengthens the cell; algal cells also have one.
Chloroplasts - ANSWER-Contain chlorophyll to absorb light for photosynthesis to make glucose.
Permanent vacuole - ANSWER-Filled with cell sap to help keep the cell turgid and support the plant.
Sub-cellular structures in animal cells - ANSWER-Include cell membrane, cytoplasm, DNA, ribosomes,
and nucleus.
Sub-cellular structures in plant cells - ANSWER-Include cell membrane, cytoplasm, DNA, ribosomes,
nucleus, mitochondria, cell wall, chloroplasts, and permanent vacuole.
, Sub-cellular structures in bacterial cells - ANSWER-Include cell membrane, cytoplasm, DNA, ribosomes,
and plasmids.
Bacterial cells - ANSWER-They have no sub-cellular structures surrounded by a membrane, eg.
nucleus, mitochondria.
Cell wall - ANSWER-Just like any other wall, the cell wall provides strength.
Cell membrane - ANSWER-What controls what moves in and out of a cell.
Red blood cell (RBC) - ANSWER-RBC has no nucleus, plant cell does.
Plant cell - ANSWER-Plant cell has a cell wall, RBC does not.
Chloroplasts - ANSWER-RBC does not contain chloroplasts or chlorophyll, plant cell does.
Permanent vacuole - ANSWER-RBC has no (permanent) vacuole, plant cell does.
Haemoglobin - ANSWER-RBC contains haemoglobin, plant cell does not.
Light microscope - ANSWER-Use a light microscope to observe, draw and label a selection of plant and
animal cells.
Microscope slide preparation - ANSWER-Peel off thin layer of tissue using forceps, place on water
drop on slide.
Stain - ANSWER-To make sub-cellular structures visible.
Thin layer of onion tissue - ANSWER-To let light pass through.
Cover slip - ANSWER-Lowered at an angle to avoid trapping air bubbles.
Total magnification calculation - ANSWER-Magnification of eyepiece lens x magnification of objective
lens eg. 10 x 4 = 40.
Field of view measurement - ANSWER-Measure diameter of field of view by using microscope to
observe a transparent ruler.
Scientific drawing rules - ANSWER-No sketching or shading - only use clear, continuous lines (with a
sharp pencil).
Magnification scale - ANSWER-Include a magnification scale (eg. x 400).
Labeling features - ANSWER-Label important features eg. nucleus.
Safety measure during cell sampling - ANSWER-Wear gloves / wash hands because stain is an irritant.
Disinfecting work surfaces - ANSWER-To prevent spread of possible infection.
Higher power objective lens - ANSWER-Use a higher power objective lens (or use an electron
microscope but a student wouldn't have access).
Sperm cell - ANSWER-Long tail / flagellum → allows sperm to swim / move towards egg.
Nerve cell - ANSWER-Long → carry electrical impulses / signals over long distances.
Muscle cell - ANSWER-Many mitochondria → ↑ rate of respiration to release energy for contraction.
