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Biology unit 5 january 2019 'scientific article'

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Reply 40

Hridita Bal

You might find this link helpful
Michael Rosbash speaks himself!
https://youtu.be/ZktzYgkhrYM

Reply 41

The Korean girl

Original post by Hedaya Mahrous

A bunch of thanks
That really helped me in dealing with the article but I have some doubts regarding ur analysis to the article-related predicted questions..
So could u please help in clarifying these doubts:

"Para 4 : stored energy of plants - hydrolysis of starch"
(any idea about the steps of the process of STARCH HYDROLYSIS??)

"photoreceptor in plants - IAA for growth"
(how is the phytochromes (photoreceptors) in the plant leaves related to the growth caused by IAA?)

"Para 11 ; clock gene, isolating the gene - restriction enzyme"
(what are the steps of the process of isolating the clock gene?? Are they the same as the steps of gene modification studied in the syllabus??)

"Para 12; identifying the clock gene- the scientist may have used the ' human genome project'"
(how this identification could be done??)

"Para 14; sequencing the gene- also human genome project"
(can u plz state the steps of gene sequencing?)

"Para 15; gene expression"
(I could not understand what should we know about gene expression or how the question could come?)

"Box 3 ; I'm not sure if they are referring the protein kinase cascade to ' regulated protein phosphorylation'"
(what is the protein kinase cascade, it is not in the syllabus, can u explain it briefly please).

"Para 17- different organisms have diff gene/ protein ( may ask ethical questions??)"
(HOW?? Can u state an example).

"Para 19; Hypothalamus Rod cells, rhodopsin (may ask ocular dominance column)"
(what is the ocular dominance column??)

Thanks in advance.
I wish u the best of luck.

1. Starch- hydrolysis of 1-4 (1-6) glycosidic bonds to produce alpha glucose

2. depends on what plant it is, if it's a long day plant, high Pfr concentration maintained stimulates the plant to release IAA, the IAA accumulates to non illuminated side of the plant, breaks the hydrogen bonds between the cellulose in the cell wall, the cell wall becomes stretchy. The water moves into the cell by osmosis, cell elongation occurs, the cell grows/ bends toward the light.

3. Btw for para 11 and 12, any gene is isolated using a specific restriction enzyme but to 'identify' the gene, gel electrophoresis is used ( compare the bands produced with the known sample), the 'human genome project' is to compare the sequence of the bases, to see any difference in the seq of base for any genes. ( also the position of the gene in the DNA)

4. Gene expression is done by the transcription factors binding to the promoter region of a specific gene, switching on the gene. The switched on gene will be transcribed and translated into protein. To turn off the gene, the transcription factor simply removes from the DNA or the repressor attaches to the transcription factor.

5. Box 3- The lipid based hormone such a thyroxine and steroid can bind to the receptor on the cell membrane, enter into the nucleus and bind/ activate the transcription factor, but protein based hormone cannot enter into the cell, instead, when it binds to the receptor on the cell membrane, the process called protein kinase cascade occurs, resulting in production of secondary messenger which will act as the activator of the transcription factor, ( so overall, in both case, the transcription factor is activated!)

6. WE humans don't have the EXACT same protein with all the mammals, for example, the poison of the frog binds to the sodium ion channel of neurons of human, inhibiting the sodium ion channel to close but the poison doesn't bind to the sodium ion channel in the neuron of the frog itself. This is because the shape of the sodium ion channel ( which is a protein) is different.

For the ethical question, its just my guess, there's been something you need to answer like- harming the animals are wrong, the experiment will kill/harm/blind the animal, animals have rights!! ect

7. The ocular dominance column is in the visual cortex ( the cerebrum) During the critical period, which is a period of time the brain is sensitive to stimulus the synapse forms, neural connection forms with brain and the eye, the bleaching of rhodopsin causes events ( I'll assume you know the events), the impulse is sent to the ocular columns in the visual cortex. If the left eye of the baby had cataract, less light enters into the eye, less impulse is sent to the brain through the optic nerve. The synapse is destroyed/ weakened and the neural connection is not formed/ less than the right eye. The neurons of the right eye overlapping in the ocular column of the left eye is dominated. Therefore, the ocular column of the right eye is larger than the left eye.

For the hypothalamus, in para 19, it says that rod cells sends day and night messages, not the impulse, to the SCN but for blind people, no impulse is sent to the SCN ( from the rod cell ) so they lose the sync with the outside world. ( I think the main point is that the SCN is in the part of hypothalamus, not the visual cortex as this is not something related to vision but circadian rhythm)

(edited 5 years ago)

Reply 42

The Korean girl

Original post by Hridita Bal

Did you mean that IAA are photoreceptors?
Phytochromes like Pfr amd Pr are the photoreceptors
IAA is a chemical
And well done! You prepared well!😁

Nah, the concentration of Pr or Pfr stimulates the release of IAA.

yeas I've worked hard but still scared because I got a weak mental :colondollar:

Reply 43

The Korean girl

Original post by Hridita Bal

You might find this link helpful
Michael Rosbash speaks himself!
https://youtu.be/ZktzYgkhrYM

Ah I got it, the PER is not the pump but it creates the concentration gradient across the membrane!!

(edited 5 years ago)

Reply 44

Hridita Bal

Original post by The Korean girl

Nah, the concentration of Pr or Pfr stimulates the release of IAA.

yeas I've worked hard but still scared because I got a weak mental :colondollar:

Pr and Pfr stimulates flowering or germination
IAA is a chemical made in the meristem cells of the shoot tip right?

Reply 45

The Korean girl

Original post by Hridita Bal

Pr and Pfr stimulates flowering or germination
IAA is a chemical made in the meristem cells of the shoot tip right?

yes, IAA is released from the tip of the shoot. Florigen for blooming flower, IAA for phototropism and cell elongation(growth) Both can be stimulated by Pr and Pfr concentration

(edited 5 years ago)

Reply 46

Hedaya Mahrous

Thank u so much
that was extremely helpful

and yeah did anyone got the marking scheme for october 2018

(edited 5 years ago)

Reply 47

colourlessness

Original post by Hedaya Mahrous

Thank u so much
that was extremely helpful

and yeah did anyone got the marking scheme for october 2018

this is the oct 18 mark scheme :smile:

WBI05_01_rms_20190124.pdf147.8KB

Goddammit 🙁

what on earth was that paper?????

Reply 50

kclhopefully

how did it go?

Original post by NoIdeaWthImdoing

Goddammit 🙁

Reply 51

potatoking007

how did you guys do in yourexam? grade boundary predictions?

Reply 52

kclhopefully

Original post by potatoking007

how did you guys do in yourexam? grade boundary predictions?

it was bad

Reply 53

colourlessness

i feel like grade boundaries are gonna be pretty high

Reply 54

NoIdeaWthImdoing

I found it hard. How was it for you guys?

Reply 55

Hridita Bal

Original post by colourlessness

i feel like grade boundaries are gonna be pretty high

Did your exam go well then?

Reply 56

colourlessness

Original post by Hridita Bal

Did your exam go well then?

it kinda did. it went okay

Reply 57

FutureStripper

I missed so many 4 mark questions on that Reading study.Question 7 was horrid. I didnt find the rest to be too hard.

Reply 58

The Korean girl

No core temperature control, slow twitch fast twitch, athlete and many typical questions came out! So many neurons and brain. I did finish the paper and it was fine for me too. But no one can guarantee how many marks I've saved from the number 7, the the respirometer question's the only mark I'm sure getting full marks in no.7 hahah