** 2013 Biology HL Before/After **

yoppo

RML wrote: »

In relation to an enzyme, explain the term optimum activity.
What did you guys write for this?

The conditions at which an enzyme works best at.

Phoenix Wright

CatEyed92 wrote: »

I have studied hard this year and so far I have sat english, geography and biology.
State exams are screwing people out of college places this year from the looks of things....
There was never a year things were so experimental or badly phrased!!

/rant

SQ were very unfair tbh

I thought the question on vegetation propagation was very unclear

SecondMan

RML wrote: »

In relation to an enzyme, explain the term optimum activity.
What did you guys write for this?

The conditions that an enzyme works best at ( eg. Temp, pH)

Lucan Bohs

These 2 parts on Q14c I couldn't get..

Name a compound which is used as a carbon source in the fermentation referred to in part (ii)..

Name the compound from which the immobilising beads are formed in the laboratory

RML

State two ways in which growth regulators in plants are similar to hormones in animals.

This one??

yoppo

Lucan Bohs wrote: »

These 2 parts on Q14c I couldn't get..

Name a compound which is used as a carbon source in the fermentation referred to in part (ii)..

Name the compound from which the immobilising beads are formed in the laboratory

glucose

sodium alginate

woopah92

Lucan Bohs wrote: »

These 2 parts on Q14c I couldn't get..

Name a compound which is used as a carbon source in the fermentation referred to in part (ii)..

Name the compound from which the immobilising beads are formed in the laboratory

I couldn't decide of they were looking for glucose or a pyruvate molecule for the first one :pac:

And the other one is sodium/calcium alginate

Slow Show

What did people say for the question on getting sick at hospitals/at home? I wrote a load for it, I'd say the right answer was in there somewhere but it'd be good to see what everyone else said.

yoppo

RML wrote: »

State two ways in which growth regulators in plants are similar to hormones in animals.

This one??

Both are chemical and both are made in one area and effect a different area...

That's what I wrote!

SecondMan

RML wrote: »

State two ways in which growth regulators in plants are similar to hormones in animals.

This one??

Slowly comes into affect
Slow movement through tissues

David1994

Slow Show wrote: »

What did people say for the question on getting sick at hospitals/at home? I wrote a load for it, I'd say the right answer was in there somewhere but it'd be good to see what everyone else said.

I did the same thing.Literally had about 10 lines of writing on it and praying I got the marks in their somewhere :P

RML

State a function of one of the structures, other than chromosomes, that you have labelled in your diagram of metaphase.
How does the structure carry out this function?

I kinda had the same answer for both of them. Spindle fibres isnt??

yoppo

Slow Show wrote: »

What did people say for the question on getting sick at hospitals/at home? I wrote a load for it, I'd say the right answer was in there somewhere but it'd be good to see what everyone else said.

I said at home you have antibodies for any antigens present. At a hospital you encounter new antigens that you haven't encountered before and your body has to product antibodies against these antigens...

I could be wrong!

Lucan Bohs

RML wrote: »

State two ways in which growth regulators in plants are similar to hormones in animals.

This one??

I said long lasting and slower action :pac:

Lucan Bohs

yoppo wrote: »

I said at home you have antibodies for any antigens present. At a hospital you encounter new antigens that you haven't encountered before and your body has to product antibodies against these antigens...

I could be wrong!

Same idea as me

weirdspider

Slow Show wrote: »

What did people say for the question on getting sick at hospitals/at home? I wrote a load for it, I'd say the right answer was in there somewhere but it'd be good to see what everyone else said.

I said hospitals are full of people with various bacterial infections so one is likely to come in contact with a bacterial infection that their immune system has never fought off. Then I said this doesn't arise at home since any bacteria present there you are likely to be immune to.
Thats one of those vague questions that they'd accept any properly backed up answer

peekachoo

RML wrote: »

State a function of one of the structures, other than chromosomes, that you have labelled in your diagram of metaphase.
How does the structure carry out this function?

I kinda had the same answer for both of them. Spindle fibres isnt??

yeah I said spindles and their function was to hold the chromatids at the equator of the cell

Jackobyte

RML wrote: »

Vegetative Propagation

I didn't know what this question was asking. "What is the name given to this type of asexual reproduction?" I couldn't tell whether they meant specifically relating to runners (I said adventitious rooting) or just asexual in general (vegetative propagation). I had both down but left the wrong one there. They are unlikely to give me the benefit either as I had vegetative propagation, runners, and layering all crossed out.

Glee_GG wrote: »

Draw a graph for heat denaturation of an enzyme, there is no graph?!

RML wrote: »

I just drew a graph similar to the pH and the rate of reaction, the temperature on the x-axis and volume of froth on the y-axis.

Yeah, this was how I answered it as well, with temperatures ranging from 0 to about 60 or so, and zero activity at the higher and lower temperatures. Glad I did an extra experiment anyway.

0mega wrote: »

6 was correct.

So 2n=6 is six chromosomes normally, but has undergone DNA replication just before mitosis so now has 6 pairs lining up along the equator? That was what I thought and absolutely everyone said I had done it wrong after the exam. Class!

sganyfx wrote: »

Dog - It's metabolism as it is an endotherm
Lizard - It's environment as it is an exotherm.

If they are getting very fussy to fix the bell curve, they could be awkward with this. Exotherm is the old term and has been replaced by ectotherm AFAIK.

Lucan Bohs wrote: »

Short Q 4 was a bitch. Did any one get it?

How could you tell it was a modified stem a) externally and b) viewing it under a microscope?

I said external was the visible axillary bud.

Lucan Bohs

Suggest a role of parasite in grand scheme of nature?

I said population control!

evancunny95

Lucan Bohs wrote: »

Suggest a role of parasite in grand scheme of nature?

I said population control!

As did I

Jackobyte

Lucan Bohs wrote: »

Suggest a role of parasite in grand scheme of nature?

I said population control!

I went with Natural selection which is more or less the same concept :P

Lucan Bohs

For 15c drawing the prey line of the graph, I threw the prey line as going up when predators decreased and going down when predators increased (ie the opposite of the line they gave you). Is this what youse did?

HungryEmperor

But parasites don't kill their hosts so how is it population control?

RML

Give the role of the enzyme RNA polymerase.

Joins mRNA to the DNA strand??

Aircontrol

Slow Show wrote: »

Short Q 4 was a bitch. Did any one get it?

How could you tell it was a modified stem a) externally and b) viewing it under a microscope?

I went a bit mad for externally and was like 'presence lenticels (can you even see them), petioles, attached to leaves blah blah' under the microscope I said vascular bundles arranged in rings.
Daughter cell haploid or diploid?
Haplod. For the reason I just pretty much explained it was meiosis blah blah not sure how I worded it but think it was OK.

Evidence that sexual reproduction had taken place?
Presence of fruit I think?

One method to produce new plants?
Grafting/layering/cutting/micropropagation?

Anyone confirm/find fault with this?

The daughter cell developed by Mitosis, considering the new plant was attached to the old plant. It didn't develop sexually. For that reason it was Diploid. My bio teacher confirmed this after the exam. Correct me if I'm wrong though

kevin12345

Lucan Bohs wrote: »

Suggest a role of parasite in grand scheme of nature?

I said population control!

I'm pretty sure I saw in the marking schemes when they asked it a while ago the answers were population control and recycling (because you can have parasitic fungi.)

Jackobyte

HungryEmperor wrote: »

But parasites don't kill their hosts so how is it population control?

They may kill off the weakest and those suffering from other illnesses anyway?

Lucan Bohs

HungryEmperor wrote: »

But parasites don't kill their hosts so how is it population control?

You could presume they lead to a deterioration in health and therefore death?!

Slow Show

Getting really frustrated with this paper and the fear that I just missed out on an A1, ugh I have French tomorrow really need to stop this.

internet_user

Lucan Bohs wrote: »

For 15c drawing the prey line of the graph, I threw the prey line as going up when predators decreased and going down when predators increased (ie the opposite of the line they gave you). Is this what youse did?

i had done it going the same way as the predators and i did it pen! when i thought about i realised its the way you're after saying and i had to tipex it all out, it looked really messy i hope i dont lose marks for that