HSC Biology Question Thread

[trainstation]

I'm having trouble understanding T cells and B cells in Search for better health. How do they interact, what happens when they do, what do these cells do and what are the processes involved?

[Rathin]

I'm having trouble understanding T cells and B cells in Search for better health. How do they interact, what happens when they do, what do these cells do and what are the processes involved?

- Helper T cells help B cells to produce more antibodies by secreting INTERLEUKIN
- Suppressor T cells stop the production of Cytotoxic (killer) T cells and B cells
- The secretion of INTERLEUKIN by helper T cells also helps differentiate the change from a B cell to a Plasma B cell in response to an antigen to produce antibodies.

[sophiegmaher]

Hey! I can't find any answers to the discussion questions of the kidney dissection prac to check my own. Any ideas?
1. Explain how the colour of each region relates to its blood supply
2. Demonstrate, using an analogy, how the kidney functions to excrete waste

[jabuibui]

What are actually adenine, guanine, cytosine and thymine? I know together they are codes and together they make nitrogen bases for nucleotides. Are they individual amino acids that comes together to make a bigger amino acids? or like bases?

Thanks 

[Quantum44]

What are actually adenine, guanine, cytosine and thymine? I know together they are codes and together they make nitrogen bases for nucleotides. Are they individual amino acids that comes together to make a bigger amino acids? or like bases?

Thanks 

Adenine, guanine, cytosine and thymine are nitrogenous bases that form part of a nucleotide. The other parts of a nucleotide are the phosphate group and pentose sugar which is deoxyribose in the case of DNA. DNA is a polymer and hence each DNA strand is formed from a long chain of nucleotides. Since DNA is a double helix, there must be two strands of DNA with the nucleotides in each strand being complementary and able to bond via hydrogen bonding. In DNA, adenine bonds with thymine and cytosine bonds with guanine. So in DNA, if one strand is ATTCCG, the complementary strand must be TAAGGC.

[sophiegmaher]

Hey guys! I'm not sure about the answers to these discussion questions from the kidney dissection prac. Any ideas?
1. Explain how the colour of each region relates to its blood supply (cortex, medulla, pelvis)
2. Demonstrate, using an analogy, how the kidney functions to excrete waste

[geminii]

Hey guys! I'm not sure about the answers to these discussion questions from the kidney dissection prac. Any ideas?
1. Explain how the colour of each region relates to its blood supply (cortex, medulla, pelvis)
2. Demonstrate, using an analogy, how the kidney functions to excrete waste

All I know for 1, is that the darker the colour of the region, the greater the blood supply to that area. I'm not too familiar with the parts of the kidney (since it wasn't part of last year's biology study design), but I think for this question you need to say that '(name of region) is a darker shade of red, therefore it has a greater blood supply.'

[vox nihili]

Hey guys! I'm not sure about the answers to these discussion questions from the kidney dissection prac. Any ideas?
1. Explain how the colour of each region relates to its blood supply (cortex, medulla, pelvis)
2. Demonstrate, using an analogy, how the kidney functions to excrete waste

All I know for 1, is that the darker the colour of the region, the greater the blood supply to that area. I'm not too familiar with the parts of the kidney (since it wasn't part of last year's biology study design), but I think for this question you need to say that '(name of region) is a darker shade of red, therefore it has a greater blood supply.'

1. I'd be interested to hear other people's thoughts, as I don't know the answer to #1 myself, but I don't think it has to do with the blood supply. The cortex of the kidney contains the glomeruli, which are—at least macroscopically—vast spaces filled with blood; whereas the majority of the cross-sectional area of the medulla is dominated by tubules, namely the LOH and the CD.

2. Would love to hear your thoughts on this first, give it a crack

[Aussie1Italia2]

Hello!

I pleading for some help with Enantiostasis and more specifically Osmoconformers and Osmoregulators. I just don't understand the difference between the two.

So some help would be much appreciated, thank you!

Arrivederci!

[sweetcheeks]

Hello!

I pleading for some help with Enantiostasis and more specifically Osmoconformers and Osmoregulators. I just don't understand the difference between the two.

So some help would be much appreciated, thank you!

Arrivederci!

Osmoconformers will have an internal osmotic pressure that is the same as their external environment. This means that they will be isotonic compared to the environment. If the osmoconformer enters an environment that has a higher salinity, its body will become isotonic with the environment. As the environment changes, osmoconformers will change with it

Osmoregulators will maintain tight tolerances of their internal environment rather than go with the changing environment. If an osmoregulator enters an environment with higher salinity, it will actively attempt to oppose the osmotic pressure of the environment. It will actively pump out salts. Osmoregulators attempt to keep stable conditions in the face of changing environments.

Conformers accept and embrace the osmotic change, whilst regulators actively oppose the change.

[janemurray]

Good model of a feedback system (MAB module)?? PLEASE & THANKYOU

[Skidous]

Good model of a feedback system (MAB module)?? PLEASE & THANKYOU

Hope this image helps

[stephjones]

could someone help me with this question?

List the advantages of excreting nitrogenous wastes as each of the following: ammonia, urea, uric acid, guanine.

i've been stuck on it for hours haha

[stephanieazzopardi]

could someone help me with this question?

List the advantages of excreting nitrogenous wastes as each of the following: ammonia, urea, uric acid, guanine.

i've been stuck on it for hours haha

Hi Steph!
So this isn't a direct syllabus dot point so it requires you to think a little bit about what you have learned about each of the different nitrogenous waste products. Here is what I think:

• Ammonia: can be excreted by some aquatic animals into their surroundings extremely fast in order to avoid a lethal accumulation of the toxic waste in their tissue. It can be excreted fast due to its simple formation from amino acids through deamination
• Urea: is far less toxic than ammonia and can accumulate in high concentrations without becoming toxic and causing tissue damage. Thus, It can also be excreted in a more concentrated form to allow for water retention depending on the organisms needs
• Uric acid: low toxicity, no water lost when excreted
• Guanine: similar to uric acid, it is the major nitrogenous waste product in arachnids

I hope this helps

[stephjones]

yes thank you so much that's wonderful!!