HSC Biology Question Thread

[studybuddy7777]

Hi again:)
In the Communication topic there's a dot point that says a nerve is a bundle of neuronal fibres. Are neuronal fibres just neurones?

Hey imtrying,
These are sometimes also called axons, but in essence neuronal fibres and neurones are the same thing.

If we want to get specific: a neurone consist of axons, cell body and dendrites. So a neurone consists of neuronal fibres.

This may lead to the question: what is an axon? Simply put axons take information away from the cell body.

[imtrying]

Hey imtrying,
These are sometimes also called axons, but in essence neuronal fibres and neurones are the same thing.

If we want to get specific: a neurone consist of axons, cell body and dendrites. So a neurone consists of neuronal fibres.

This may lead to the question: what is an axon? Simply put axons take information away from the cell body.

Thanks!

[006609]

Hi!

I was wondering if you could explain the difference between prevention and control in terms of malaria?
I personally believe prevention has to do with vaccines and control with other measures such as mosquito nets and appropriate clothing. But
couldn't some control measures be regarded as prevention as well? Sorry, I've just gotten confused...

Thanks in advance!!

[Skidous]

Hi!

I was wondering if you could explain the difference between prevention and control in terms of malaria?
I personally believe prevention has to do with vaccines and control with other measures such as mosquito nets and appropriate clothing. But
couldn't some control measures be regarded as prevention as well? Sorry, I've just gotten confused...

Thanks in advance!!

Hey, so prevention is the use of antimalarial drugs (since there is not a vaccine for malaria yet) and other forms of protections such as repellents and long clothing (long-sleeves on shirts and pants)

Control has to deal with the maintenance of the vectors or causes for the disease. This in the past has been DDT and removal of swamps that promote mosquito growth but has changed to other methods such as the IRS as a preventative also seeks to help control malarial infections in Africa. Vector management plans are also set in place to control the spread of malaria by Anopheles

[Blissfulmelodii]

Hi!

I was wondering if you could explain the difference between prevention and control in terms of malaria?
I personally believe prevention has to do with vaccines and control with other measures such as mosquito nets and appropriate clothing. But
couldn't some control measures be regarded as prevention as well? Sorry, I've just gotten confused...

Thanks in advance!!

For malaria prevention would be not allowing mosquito's to bite humans (and that's your mosquito nets, protective clothing, insect repellent etc) and the control would be breaking the plasmodium's life cycle (so draining swamps, killing mosquito's with insecticides etc)

As for the actual terms of prevention and control don't take my word for it but I think that has more to do with short term vs long term fixes... Prevention is looking at an immediate way to stop from catching the disease while control is looking at long term measures to stop the spread

[Skidous]

Just answered a question if a facebook page that may help some people out

"Hi, I just answered Q31 of 2011 HSC. I included biological understanding surrounding the mutagenic nature of radiation through Beadle and Tatum, knowledge of polypeptide sequences and bacterial/microflora imbalances - when I checked sample answers only polypeptides were mentioned. The marking criteria did not give specific examples - Am I technically correct? Because these advancements were the most obvious at the time for me, does it matter what scientists or what historical advancements I include?
Thanks for your time"


My response to this was

Well you are not incorrect with the first 2 but what you should base it around is not Beadle and Tatum and other scientists such as Pasteur and Koch who discovered that microbes and pathogens caused diseases and not spontaneous generation/miasma theory. And you could also talk about the discovery of penicillin by Alexander Fleming to the development of other antibiotics as well as how their misuse has lead to antibiotic resistant bacteria such as MRSA and VRSA.

Hope this helps you guys

[Skidous]

Hey imtrying,
These are sometimes also called axons, but in essence neuronal fibres and neurones are the same thing.

If we want to get specific: a neurone consist of axons, cell body and dendrites. So a neurone consists of neuronal fibres.

This may lead to the question: what is an axon? Simply put axons take information away from the cell body.

Actually no, that is incorrect

A NERUONE is a single nerve cell containing the soma, axon and dendrites

A Neruonal Fibre is a collection of axons from many nerones. This what a Nerve is.

To simplify it: Neuron-Nerve Cell
Neuronal Fibres- Many Neurons

[imtrying]

when it comes to the electrochemical changes that occur in the membranes of neurons, what initially stimulates the movement of ions?
also, i noticed that extra clarification on my last question, thanks:)

[Sssssrr]

hi,
when a dotpoint say 'process information from secondary sources', does that mean that they'll provide information in the exam which we interpret, or do we have to go in with info already memorised to answer the question?
thanks!

[Skidous]

when it comes to the electrochemical changes that occur in the membranes of neurons, what initially stimulates the movement of ions?
also, i noticed that extra clarification on my last question, thanks:)

There are actually 3 channels on a neuron that allows Na to enter the membrane

Ligand-Gated Channels:  Respond to neurotransmitters
Mechanically-Gated Channels: They open to physically motion such as stretching it
Voltage-Gated Channels: These open once the membrane threshold is reached (-55mV)

Once one part of the membrane reaches peak depolarisation (40mV) this stimulates other voltage gated channels along the neuron to also open and then move that change along the neuron to the synapses

After this the sodium channels close and the Potassium channels open letting out too much of the Potassium where the membrane is in hyperpolarisation (-75mv) and the Sodium Potassium pump brings the membrane back to resting potential (-70mV)

Nb action potential is a all-or-none effect where if the stimuli does not cause the membrane to reach -55mV then a graded potential occurs where it is only in the localised area and the membrane quickly returns to its resting potential

Another NB this all takes place in the span of 4 MILLOSECONDS! Now if only wifi was that fast

Hope this helps

[Blissfulmelodii]

hi,
when a dotpoint say 'process information from secondary sources', does that mean that they'll provide information in the exam which we interpret, or do we have to go in with info already memorised to answer the question?
thanks!

Usually when they say something about secondary sources it means you need to go and do your own research. In the exam they would have specific questions for you to integrate that knowledge. For example blood testing technology is something that you go and research about and i have seen questions asking about pulse oximeter etc.

[Skidous]

hi,
when a dotpoint say 'process information from secondary sources', does that mean that they'll provide information in the exam which we interpret, or do we have to go in with info already memorised to answer the question?
thanks!

When it talks about processing secondary sources you will normally relate it to 2 parts

1: The actual research (so your own knowledge from past research tasks or assessments/exams)
2: The analysis of that secondary source (validity, reliability and accuracy)

Validity: is who has written the secondary source (qualifications- do they work in the field you are researching, do they have bias, are they well known)
Reliability: Cross-Referencing the info gathered with other valid sources (if it's the same then the source is valid)
Accuracy: Relevance to the task (is it helpful, does it answer your question, is it recent data [usually gathered within the last 5-10 years] and is it reliable and valid)

Hope this helps

[imtrying]

Very sorry to keep asking questions in different posts...im finding the neuron thing a bit confusing.
Whats the go with synapses and neurotransmitters? Would i be right in saying that when the impulse reaches the synapse at the end of the axon, a neurotransmitter is released and this allows the electrical impulse to be changed to a chemical one as it crosses the synapse and then back to electrical impulse at the dendrites?

[:3]

Very sorry to keep asking questions in different posts...im finding the neuron thing a bit confusing.
Whats the go with synapses and neurotransmitters? Would i be right in saying that when the impulse reaches the synapse at the end of the axon, a neurotransmitter is released and this allows the electrical impulse to be changed to a chemical one as it crosses the synapse and then back to electrical impulse at the dendrites?

Precisely. Except, that the neurotransmitter diffuses to the next dendrite and stimulates a new, but same electrical impulse at the dendrites.

[Blissfulmelodii]

Precisely. Except, that the neurotransmitter diffuses to the next dendrite and stimulates a new, but same electrical impulse at the dendrites.

Is it concerning that my class is also doing communication yet I am not understanding any of this?? Honestly the only thing that makes sense to me from that topic is the eye and ear stuff...