GCSE AQA biology semi unofficial mark scheme of both units.

My answers from the test that I can remember from both units, It's going to be mixed together I don't have the time nor the effort to try and ask people to come up with an organised unofficial mark scheme so you can figure out from which units the questions come from. Please note answers that I have given could be potentially wrong and are just answers for you to confer with.

Bile question

Glycerol, is the by product. (1 mark)

2 variables to be kept the same? (2 marks)
-Same volume of milk (fat)
-Same amount of lipase used.

Why did the pH go down? (1 mark)

Because fatty acids were being produced as a result of digestion of fat.

How can you tell from the graph that bile helped digestion?(2 marks)

Because from the graph you can see a steeper slope that water, so faster digestion of fat.

All I can remember for this question, could be another end part but that's the main part.

Alleles & genetics.

Describe where the dna is found in human cells? (2 marks)

Dna found in the nuclear cells as nuclear Dna.

Minimum allele that needs to be present for polydactyly to be expressed?(1 mark)

Well considering it is a dominant condition, only one needs to be present.

Minimum allele that needs to be present for cystic fibrosis to be expressed? (1 mark)

It's recessive, so two.

Mendeleev's experiment.

The ratio I personally think it's 3:1 as the experiment is directly from his work which consisted of the same ratio esp from the genetic diagram. Also 729/228 = 3.1 makes sense for the ratio to be 3:1. (1 mark)

Give two reasons why his work wasn't accepted or on those lines which is what they were essentially asking for. (2 marks)

i) Because he wasn't a renowned scientist, a monk his work wasn't accepted.
ii) At the time inheritance factors weren't known and hence they didn't really appreciate how important Mendeleev work.

For the tick boxes, if you do the genetic diagram it was most definitely.(3 marks)

-Homo
-Homo
-Hetero


This is all I can remember for this.

Cardiac output.

5624 volume ml/blood min, units were given dw.

Explain why person two had a lower cardiac output? (2 mark)

Because his stroke volume was much lower, which meant a lower cardiac output.

Explain why person one ran faster than person two? (5 marks)

Because person one had a greater cardiac output this meant more blood flow to the muscles from the heart. Therefore a constant supply of glucose and oxygen reached the muscles allowing aerobic respiration to release energy compared to anaerobic which releases less energy and lactic acid. More energy released for running.

Fossils

Explain he formation of the fossil archaeopteryx? (2 marks)

The animal must first die, and the hard parts of the animal were not able to decay leaving a fossil.

Give two reasons why there were gaps in the record? (2 marks)

i) More fossils are yet to still be discovered.
ii)Fossil couldn't be formed because of decay.

Explain how species could be formed from the ancestor archaeopteryx? ( 4 marks)

You must first explain natural selection, and then speciation. So something like for e.g Variations in gene caused certain characteristics to be better suited for the environment these animals survived (natural selection) and passed their genes to the future generations. These animals would become so different that interbreeding successfully would not be viable so a specie has been formed. Isolation must be said at the start of this question though.

Cell structure

Mitochondria - Sight at which respiration occurs. (1 mark)

Ribosome - Where protein synthesis occurs. (1 mark)

Muscle cell magnification is 400. idk how many marks.

Explain why muscle cells cover the stomach? (2 marks)

Help to churn the food which would mix with the digestive enzymes.

Plants

Plants make glucose, energy can be released from glucose.
Explain how plants make energy? (2 marks)

Plants do photosynthesis which light is absorbed from the sun in the chlorophyll to produce glucose which then respiration occurs releasing energy.

Name the four uses of glucose in the plant? (4 marks)

i) To produce fat or oil storage
ii) To produce cellulose for cell wall.
iii) To produce protein.
iiii)??? - I don't know the fourth one to be honest, since they said glucose is needed for energy respiration already.

Kidney transplant and dialysis.

First graph asks you to draw what would happened to the urea concentration when dialysis occurs, because the urea concentration of the blood was 28 and urea is toxic all of that must be removed. So start of the graph would start from 28 to 0 at the end.(1 mark)

For the second graph, you've been told that 6 mmol was the average concentration which is what was given on the results table, so all you do on the graph is draw a flat line from 6 to the end of dialysis. (1 mark)

Explain why kidney rejection may occur? (3 marks)

Because the body would find the protein surface of the kidney foreign and therefore an antigen. It would use the immune system to fight against it and now they kindey has become rejected.

What could be done to reduce the chances of rejection? (1 mark)

immunosuppressants.

Explain how urine is produced? (5 marks)

Blood from the renal artery comes at high blood pressure into the bowman's capsule. Small molecules are filtered such as glucose, water, ions and urea. All of glucose is reabsorbed by atp (active transport), some of the water as needed by the body is reabsorbed by osmosis?. Ions as needed by the body by atp and no urea is absorbed. Urine has formed.

Sports Drinks.

Explain why the person after the second run would be the first one to be exhausted? (2 marks)

Because sport drink B contains the lowest amount of glucose, less respiration would be able to be done and hence less energy release for movement can be done.

Explain how a person could be ill if the person drinks too much of a sports drink? (3 marks)

Sports drinks are rich in glucose and therefore this would increase the concentration of glucose in the blood. For a diabetic who can not control their glucose in the blood, this would cause a high blood sugar levels and could make the person ill.

Temperature regulation (3 marks)

Thermoregulatory centre in the brain has receptors which are sensitive to temperature. Can detect the temperature of blood flowing through the brain.

Blood

Two substances that the blood carries other than oxygen and glucose? (2 marks)

i) Water
ii) Carbon dioxide

I can't quite word the next question but I'm fairly sure the answer was. (2 marks)

i)Platelets
ii)Plasma

What's the type of tissue the heart is made up of? (1 mark)

Muscle.

Explain how the oxygen gets into the blood? (2 marks)

Diffusion of oxygen from the lungs by alveoli, oxygen reacts with the haemoglobin in the rbc, to form haemoglobin.

Lungs

What's the flexible rubber sheet? (1 mark)

It's the diaphragm.

Explain why the balloons inflate when the flexible rubber sheet is pushed downwards? (3 marks)

Pushing it downwards caused the volume of air in the jar to increase, this caused the pressure to lower and hence air would be forced in.

Waste question

Explain why on a world scale waste has been increasing? (2 marks)

i)Population of the world has been increasing.
ii)Increase in standard of living.

Calculate the recycled, if memory does me well it's 41.4%. (1 mark)

For and against question, that was simple enough as long as you refer to the table, but also no data was given in the table to show if any of the waste was reused, could be a potential mark.

Photosynthesis of plants allows sequestering of carbon dioxide, give another way? (1 mark)

Oceans allowing carbon dioxide to dissolve.



Fusarium

What gas substance was released into the fermenter for aerobic respiration? (1 mark)

Oxygen.

What substance was put into the fermenter for aerobic respiration? (1 mark)

Glucose.

Give two advantages of mycroprotein ( 2 marks)

i) Vegetarians are able to eat mycroprotein.
ii) Cheaper than killing animals.

Fish question, not sure with how it was worded or anything but. (2 marks).

Lots of gill filaments, therefore an increase in surface area and hence faster and more absorption.

If people can remember any more, please leave a comment and I'll try my best to add it on.

Cell structure

Mitochondria - Sight at which respiration occurs. (1 mark)

Anyone online to revise , need help , pm me

What do you need help on hun?

My answers from the test that I can remember from both units, It's going to be mixed together I don't have the time nor the effort to try and ask people to come up with an organised unofficial mark scheme so you can figure out from which units the questions come from. Please note answers that I have given could be potentially wrong and are just answers for you to confer with.

Bile question

Glycerol, is the by product. (1 mark)

2 variables to be kept the same? (2 marks)
-Same volume of milk (fat)
-Same amount of lipase used.

Why did the pH go down? (1 mark)

Because fatty acids were being produced as a result of digestion of fat.

How can you tell from the graph that bile helped digestion?(2 marks)

Because from the graph you can see a steeper slope that water, so faster digestion of fat.

All I can remember for this question, could be another end part but that's the main part.

Alleles & genetics.

Describe where the dna is found in human cells? (2 marks)

Dna found in the nuclear cells as nuclear Dna.

Minimum allele that needs to be present for polydactyly to be expressed?(1 mark)

Well considering it is a dominant condition, only one needs to be present.

Minimum allele that needs to be present for cystic fibrosis to be expressed? (1 mark)

It's recessive, so two.

Mendeleev's experiment.

The ratio I personally think it's 3:1 as the experiment is directly from his work which consisted of the same ratio esp from the genetic diagram. Also 729/228 = 3.1 makes sense for the ratio to be 3:1. (1 mark)

Give two reasons why his work wasn't accepted or on those lines which is what they were essentially asking for. (2 marks)

i) Because he wasn't a renowned scientist, a monk his work wasn't accepted.
ii) At the time inheritance factors weren't known and hence they didn't really appreciate how important Mendeleev work.

For the tick boxes, if you do the genetic diagram it was most definitely.(3 marks)

-Homo
-Homo
-Hetero


This is all I can remember for this.

Cardiac output.

5624 volume ml/blood min, units were given dw.

Explain why person two had a lower cardiac output? (2 mark)

Because his stroke volume was much lower, which meant a lower cardiac output.

Explain why person one ran faster than person two? (5 marks)

Because person one had a greater cardiac output this meant more blood flow to the muscles from the heart. Therefore a constant supply of glucose and oxygen reached the muscles allowing aerobic respiration to release energy compared to anaerobic which releases less energy and lactic acid. More energy released for running.

Fossils

Explain he formation of the fossil archaeopteryx? (2 marks)

The animal must first die, and the hard parts of the animal were not able to decay leaving a fossil.

Give two reasons why there were gaps in the record? (2 marks)

i) More fossils are yet to still be discovered.
ii)Fossil couldn't be formed because of decay.

Explain how species could be formed from the ancestor archaeopteryx? ( 4 marks)

You must first explain natural selection, and then speciation. So something like for e.g Variations in gene caused certain characteristics to be better suited for the environment these animals survived (natural selection) and passed their genes to the future generations. These animals would become so different that interbreeding successfully would not be viable so a specie has been formed. Isolation must be said at the start of this question though.

Cell structure

Mitochondria - Sight at which respiration occurs. (1 mark)

Ribosome - Where protein synthesis occurs. (1 mark)

Muscle cell magnification is 400. idk how many marks.

Explain why muscle cells cover the stomach? (2 marks)

Help to churn the food which would mix with the digestive enzymes.

Plants

Plants make glucose, energy can be released from glucose.
Explain how plants make energy? (2 marks)

Plants do photosynthesis which light is absorbed from the sun in the chlorophyll to produce glucose which then respiration occurs releasing energy.

Name the four uses of glucose in the plant? (4 marks)

i) To produce fat or oil storage
ii) To produce cellulose for cell wall.
iii) To produce protein.
iiii)??? - I don't know the fourth one to be honest, since they said glucose is needed for energy respiration already.

Kidney transplant and dialysis.

First graph asks you to draw what would happened to the urea concentration when dialysis occurs, because the urea concentration of the blood was 28 and urea is toxic all of that must be removed. So start of the graph would start from 28 to 0 at the end.(1 mark)

For the second graph, you've been told that 6 mmol was the average concentration which is what was given on the results table, so all you do on the graph is draw a flat line from 6 to the end of dialysis. (1 mark)

Explain why kidney rejection may occur? (3 marks)

Because the body would find the protein surface of the kidney foreign and therefore an antigen. It would use the immune system to fight against it and now they kindey has become rejected.

What could be done to reduce the chances of rejection? (1 mark)

immunosuppressants.

Explain how urine is produced? (5 marks)

Blood from the renal artery comes at high blood pressure into the bowman's capsule. Small molecules are filtered such as glucose, water, ions and urea. All of glucose is reabsorbed by atp (active transport), some of the water as needed by the body is reabsorbed by osmosis?. Ions as needed by the body by atp and no urea is absorbed. Urine has formed.

Sports Drinks.

Explain why the person after the second run would be the first one to be exhausted? (2 marks)

Because sport drink B contains the lowest amount of glucose, less respiration would be able to be done and hence less energy release for movement can be done.

Explain how a person could be ill if the person drinks too much of a sports drink? (3 marks)

Sports drinks are rich in glucose and therefore this would increase the concentration of glucose in the blood. For a diabetic who can not control their glucose in the blood, this would cause a high blood sugar levels and could make the person ill.

Temperature regulation (3 marks)

Thermoregulatory centre in the brain has receptors which are sensitive to temperature. Can detect the temperature of blood flowing through the brain.

Blood

Two substances that the blood carries other than oxygen and glucose? (2 marks)

i) Water
ii) Carbon dioxide

I can't quite word the next question but I'm fairly sure the answer was. (2 marks)

i)Platelets
ii)Plasma

What's the type of tissue the heart is made up of? (1 mark)

Muscle.

Explain how the oxygen gets into the blood? (2 marks)

Diffusion of oxygen from the lungs by alveoli, oxygen reacts with the haemoglobin in the rbc, to form haemoglobin.

Lungs

What's the flexible rubber sheet? (1 mark)

It's the diaphragm.

Explain why the balloons inflate when the flexible rubber sheet is pushed downwards? (3 marks)

Pushing it downwards caused the volume of air in the jar to increase, this caused the pressure to lower and hence air would be forced in.

Waste question

Explain why on a world scale waste has been increasing? (2 marks)

i)Population of the world has been increasing.
ii)Increase in standard of living.

Calculate the recycled, if memory does me well it's 41.4%. (1 mark)

For and against question, that was simple enough as long as you refer to the table, but also no data was given in the table to show if any of the waste was reused, could be a potential mark.

Photosynthesis of plants allows sequestering of carbon dioxide, give another way? (1 mark)

Oceans allowing carbon dioxide to dissolve.



Fusarium

What gas substance was released into the fermenter for aerobic respiration? (1 mark)

Oxygen.

What substance was put into the fermenter for aerobic respiration? (1 mark)

Glucose.

Give two advantages of mycroprotein ( 2 marks)

i) Vegetarians are able to eat mycroprotein.
ii) Cheaper than killing animals.

Fish question, not sure with how it was worded or anything but. (2 marks).

Lots of gill filaments, therefore an increase in surface area and hence faster and more absorption.

If people can remember any more, please leave a comment and I'll try my best to add it on.

Gcse aqa core science physics , are you doing this exam ? Pm me

Oh no sorry im not hun