# BIOL4 Biology Unit 4 Exam - 13th June 2011 watch

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1. (Original post by SashaLuLu)
hey, does anybody reckon they could ask a 5 mark question on conservation? For example, the importance of it? if so what will you include?

Also, do you think they can ask a five marker on climate change, carbon dioxide and methane?

Thanks
5 Marker on conservation.....No WAY!
2. (Original post by Superlogon)
He's really good! Thanks!

say there is a five mark question and you get marks for saying:

1
2
3
4
5

1
3
4
5

now, does this mean that i will lose the marks for 3,4,5 because i didn't have a point for 2. resulting in me only getting the mark for 1? so one mark?

say there is a five mark question and you get marks for saying:

1
2
3
4
5

1
3
4
5

now, does this mean that i will lose the marks for 3,4,5 because i didn't have a point for 2. resulting in me only getting the mark for 1? so one mark?

No, you would get 4 marks as you've said 4 points. Each point is marked independently from each other.
5. (Original post by SashaLuLu)
No, you would get 4 marks as you've said 4 points. Each point is marked independently from each other.
oh thank goodness! it always confused me because they put in semi colons making me think that they all had to be related to each other.
6. can anyone explain jan 11 ques 5 b please??

no idea how to get right answer
7. (Original post by dents)
can anyone explain jan 11 ques 5 b please??

no idea how to get right answer
It is the value of the medium light intensity at 20 degrees + the value of respiration at the same temp. :

2.4 + 0.35 = 2.75

Good luck with the exam today...!!
8. can someone quickly do a 5 mark answer to:

Explain the importance of conservation in an ecosystem...
9. just a quick question. what is the experiment called when you put elodea in water to measure the rate of photosynthesis? and whats the experiment called when u place an organism in one of those tube things where is respires and there is a pressure change, measuring the rate of respiration?
10. (Original post by tehsponge)
Lol but I'm not revising... I'm sitting here just staring at the electron transport chain pages of NT.
How are you relaxed
That's actually my favourite part

All you need to remember is that reduced NAD and reduced FAD carry hydrogen atoms from the krebs cycle, link reaction and glycolysis and then transport the hydrogen protons through carrier proteins don't forget that the hydrogen atoms are reduced before they are transported to replace the electrons in the electron chain, oxygen is the final acceptor of the electron and reacts with protons diffusing out the ATP Synthase protein.

Chemiosmosis is basically the transport of these protons through the carrier proteins against a concentration gradient, so that the protons will move across a diffusion gradient through ATP Synthase which produces energy, ATP Synthase uses this energy for phosphorylation of ADP+Pi to form ATP.

In cases where there is no ATP Synthase such as in brown fat the protons will move through other protein channels and their energy is no longer converted to chemical energy but heat energy which heats the cell up.

NADH and FADH are recycled to be used again, and in anaerobic respiration NADH is recycled by converting pyruvate into lactate, in yeast it produced CO2 which means matter is lost therefore not reversible.

Glycolysis/kreb and link are relatively easy, just need to remember the carbon numbers(is what my book says) although I just went ahead and remembered the names just because I can.

(Original post by SK-mar)
can someone quickly do a 5 mark answer to:

Explain the importance of conservation in an ecosystem...
1. Conservation is the act of preventing complete succession(deflected succession)
2. If succession isn't deflected the ecosystem reaches a climax community which is similar to other climax communities
3. We want to preserve alleles to maintain diversity
4. diversity is useful because it means that plants are more likely to survive in the case of disruptions in abiotic factors/niches
5. consumers feed on the diversity of plants, therefore more food sources for different organisms, blablabla secondary consumers feed on primary consumers maintaining trophic level or something.
6. humans can use the alleles/genes for medicine, to develop cures and treatments to diseases, can be used for biotechnology, ethical reasons like preserving organisms.

It's not a very confident answer But I guess it will do.
11. (Original post by SK-mar)
just a quick question. what is the experiment called when you put elodea in water to measure the rate of photosynthesis? and whats the experiment called when u place an organism in one of those tube things where is respires and there is a pressure change, measuring the rate of respiration?
Respirometer?

(Original post by SK-mar)
can someone quickly do a 5 mark answer to:

Explain the importance of conservation in an ecosystem...
Wouldn't that be talking about niches and genetic diversity and how it's all so brilliant?
12. can anybody explain what biomass is + dry biomass?
13. By the way I posted this in another thread but nobody seems to be posting there anymore.
Correct me if I'm wrong, as usual.
(Original post by Zetsubeau)
Genes are a section of DNA that is responsible for a characteristic. This is by coding for a protein such as an enzyme, etc. Genes are carried on chromosomes. They can be expressed (exons) or not expressed (introns).
An organisms genetic code is given during reproduction. When the reproduction is asexual: simple! The genetics of the parent are identical to the child/daughter. When it's sexual, the gametes carry half the genetics each and form a zygote which contains a split of genes. This is where expression is slightly more complex.
When a gene (genotype) is expressed, it creates a phenotype (a characteristic, e.g. blue eyes, brown hair, formation of proto-oncogenes, etc.). When a genotype causes a phenotype, it is dominant. Other genes are often carried which also have a phenotype, but may be dominant or recessive. If it is recessive, the dominant gene is expressed and the recessive is not. When a gene is present but not expressed, it's being carried. The organism is a carrier. Sometimes both are expressed, however, causing a co-dominance (such as AB bloodtype). When a gene is sex-linked, it's carried on the Y chromosome, as that's the chromosome that varies between sexes. This means it's only present in one sex.
(Original post by SashaLuLu)
can anybody explain what biomass is + dry biomass?
Biomass the the weight of the organism. Dry is the organism's weight without water.
14. (Original post by Kishanpatel)
It is the value of the medium light intensity at 20 degrees + the value of respiration at the same temp. :

2.4 + 0.35 = 2.75

Good luck with the exam today...!!
cheers

all i did wrong was in my rush to quickly finish paper kept on looking at the wrong axis but didnt realise, hope i dont do that in exam.

gud luk.
15. (Original post by Stratos)
1. Conservation is the act of preventing complete succession(deflected succession)
2. If succession isn't deflected the ecosystem reaches a climax community which is similar to other climax communities
3. We want to preserve alleles to maintain diversity
4. diversity is useful because it means that plants are more likely to survive in the case of disruptions in abiotic factors/niches
5. consumers feed on the diversity of plants, therefore more food sources for different organisms, blablabla secondary consumers feed on primary consumers maintaining trophic level or something.
6. humans can use the alleles/genes for medicine, to develop cures and treatments to diseases, can be used for biotechnology, ethical reasons like preserving organisms.

It's not a very confident answer But I guess it will do.
That's what I thought. Good.

Side note though: ethics isn't a major point.
16. (Original post by SashaLuLu)
can anybody explain what biomass is + dry biomass?
According to NT: 'biomass is the total mass of living material in a specific area at a given time. It is usually measured as dry biomass because the amount of water in an organism is very variable'

hope that helped
17. (Original post by Zetsubeau)
Genes are a section of DNA that is responsible for a characteristic. This is by coding for a protein such as an enzyme, etc. Genes are carried on chromosomes. They can be expressed (exons) or not expressed (introns).
An organisms genetic code is given during reproduction. When the reproduction is asexual: simple! The genetics of the parent are identical to the child/daughter. When it's sexual, the gametes carry half the genetics each and form a zygote which contains a split of genes. This is where expression is slightly more complex.
When a gene (genotype) is expressed, it creates a phenotype (a characteristic, e.g. blue eyes, brown hair, formation of proto-oncogenes, etc.). When a genotype causes a phenotype, it is dominant. Other genes are often carried which also have a phenotype, but may be dominant or recessive. If it is recessive, the dominant gene is expressed and the recessive is not. When a gene is present but not expressed, it's being carried. The organism is a carrier. Sometimes both are expressed, however, causing a co-dominance (such as AB bloodtype). When a gene is sex-linked, it's carried on the Y chromosome, as that's the chromosome that varies between sexes. This means it's only present in one sex.
Firstly exons and introns are merely bases in a mRNA sequence they aren't genes in themselves, a gene contains introns when it hasn't been edited yet basically and a edited gene contains exons only.

And sex-linked genes merely mean that the gene is present on a heterosomal chromosome(X or Y) it and can be present in both genders, but it more likely to be present in males e.g. in colour blindness.

But the rest sounds fine I guess.
18. (Original post by Stratos)
Firstly exons and introns are merely bases in a mRNA sequence they aren't genes in themselves, a gene contains introns when it hasn't been edited yet basically and a edited gene contains exons only.

And sex-linked genes merely mean that the gene is present on a heterosomal chromosome(X or Y) it and can be present in both genders, but it more likely to be present in males e.g. in colour blindness.

But the rest sounds fine I guess.
Good enough. Sex-linkage is a bit confusing to me but it's not a big deal, I understand it well enough.
19. Heyyy can someome help me... ive seen this Q a couple of times and i really cant find the answer!

What are the advantages of using a pyramid of biomass/measuring in biomass???
20. (Original post by Abby :))
Heyyy can someome help me... ive seen this Q a couple of times and i really cant find the answer!

What are the advantages of using a pyramid of biomass/measuring in biomass???
Energy is lost between each consumer? I think.

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