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Edexcel IGCSE Biology 1B Unofficial Mark Scheme

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Original post by jack_harrison
I'm guessing what would get you 4 marks is something along these lines:

Fungi use saprophytic/saprotrophic nutrition. They secrete enzymes such as amylase which break down/digest the log into soluble products (such as glucose for respiration) which are then reabsorbed by the fungi via active transport.


Thanks for your answer. I wasnt aware of the technical name of Saprotrophic nutrition and this is what i put: Fungi release enzymes outside their body. This breaks down particles for example proteins into amino acids (i didnt say starch to glucose) As fungi due this they respire more since they need more energy. (Didnt include bit aboht absorbing soluble products back into cell). I know my answer wasnt very good. But how many mark(s) would i get for this answer do u think?
Original post by WillElliot
Thanks for your answer. I wasnt aware of the technical name of Saprotrophic nutrition and this is what i put: Fungi release enzymes outside their body. This breaks down particles for example proteins into amino acids (i didnt say starch to glucose) As fungi due this they respire more since they need more energy. (Didnt include bit aboht absorbing soluble products back into cell). I know my answer wasnt very good. But how many mark(s) would i get for this answer do u think?


To be honest I reckon that'd be a solid 3 marks maybe even 4 but it's in the examiner's hands from here :l I think there'd be a mark for secretion of enzymes, a mark for break down maybe the example of digestion and possibly the respiration too.
(edited 6 years ago)
Original post by jack_harrison
I'm guessing what would get you 4 marks is something along these lines:

Fungi use saprophytic/saprotrophic nutrition. They secrete enzymes such as amylase which break down/digest the log into soluble products (such as glucose for respiration) which are then reabsorbed by the fungi via active transport.


Thank u for answer. I forgot about the technical name of Saprotrophic nutrition, and this is what i put: Fungi secrete enzymes outside their body, which break down particles (forgot to mention sugars and glucose) such as proteins into amino acids. They also break down Carbon in the dead trees and as they decompose they need more energy so respire at a higher rate and they release Co2. (I forgot to mention ABSORBING DIGESTED PARTICLES and forgot to use the phrase 'insoluble into soluble' ) What mark would u give my answer and could u tell me for which points u would give me the mark for. THANKS FOR UR HELP
i think it was gg
Original post by ChezPlayz
Would you get the marks if you spelt it as 'Hemoglobin'


Spelling pretty much doesn't matter in biology as long as its phonetic so you'll be fine.
Except for mitosis and meiosis cause they could look like each other i guess.
Can anyone advise how many marks the sperm calculation question was and the quadrat calculation question? And any other maths questions?
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Avatar for RixRox
RixRox
1
Original post by JMR2017
Smoking: Health hazard, should not smoke in public buildings. Contains Carcinogens, e.g tar, carbon monoxide (attatches to haemoglobin better than oxygen) carcinogens lead to lung cancer


Emphysema
Bronchitis
Original post by LlamaLlama1730
Correct me if Im wrong, for the tick boxes in the starch glucose question I think it was

All no for starch
No, Yes, Yes, No for glucose


Starch | Glucose
1 No | No
2 No | No
3 No | Yes
4 No | No
Original post by RixRox
Emphysema
Bronchitis


- Health Hazard:
- Carcinogens (cancer-causing compounds) present
- Unhealthy especially for children (undeveloped immune systems)
- Can be a safety hazard (could catch fire)

I'm sure, if you were a non-smoker, it would be very difficult to reach them types of diseases, however, you will probably still get one mark, not two as they are diseases linking to the same organ (lung).
Original post by Mehnaz Arabi
i think it was gg


Correct.
gg - Homozygous Recessive.

The recessive allele, g did not cause the disease.

The percentage for the question afterwards would then be 0%
and the question beforehand which asked about the amount of individuals with both X and Y chromosomes would be all of the males so would therefore be 8.
Original post by ihs0201
Posted from TSR Mobile

Wasn't the maltase one no as maltase is for maltose to glucose not starch to glucose?

Yup it was supposed to be no. Because maltase does not digest starch
Original post by WillElliot
Thank u for answer. I forgot about the technical name of Saprotrophic nutrition, and this is what i put: Fungi secrete enzymes outside their body, which break down particles (forgot to mention sugars and glucose) such as proteins into amino acids. They also break down Carbon in the dead trees and as they decompose they need more energy so respire at a higher rate and they release Co2. (I forgot to mention ABSORBING DIGESTED PARTICLES and forgot to use the phrase 'insoluble into soluble' ) What mark would u give my answer and could u tell me for which points u would give me the mark for. THANKS FOR UR HELP


Marking Overall:
- Saprotrophic Nutrition (1 mark)
- The fungi secrete digestive enzymes (1 mark)
- These digestive enzymes then break down large molecules into small molecules such as proteins to amino acids, starch to glucose (starch -> maltose using amylase, maltose -> glucose using maltase) (1-2 marks)
- They then use these smaller molecules for growth, repair and energy release through respiration (1 mark)
- This process of respiration also releases CO2 into the atmosphere whilst the fungi use up oxygen in the atmosphere (maybe 1 mark)
Original post by Aggrawalkriti
Yup it was supposed to be no. Because maltase does not digest starch


Correct - exactly what I was thinking.
Starch -> Maltose by Amylase
Maltose -> Glucose by Maltase

Therefore, Maltase is shown to not be able to break down Starch so no Glucose is found in the solution.
Original post by JMR2017
Starting with Q1

Parts of Lung; Windpipe, Bronchus, Bronchiole
Lung like a tree because both have many branches

When you inhale, Pressure decreases, Volume increases, Diaphragm pulls downwards and contracts, air drawn in, internal IC muscles relax, exterior IC muscles contract.

If anyone has answers to any other questions, post below, I will try to keep adding more questions.


Thank You, feels good to know that something I wrote for the paper was correct.
I wrote bronchiole, but many said it was alveoli
why opt yes [3rd one]for glucose?
Original post by LlamaLlama1730
Correct me if Im wrong, for the tick boxes in the starch glucose question I think it was

All no for starch
No, Yes, Yes, No for glucose

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