biology unit 3/4

Hey Guys, what is two primary types of genes?

yr12student22
I'm pretty sure the two primary types of genes we need to know about are structural and regulatory genes.

what are the biological consequence of increased genetic diversity? and what are the biological consequences of decreased genetic diversity?

yr12student22
Increased genetic diversity results in higher adaptive potential and lower chance of inbreeding. Conversely, decreased genetic diversity results in lower adaptive potential and a higher chance of inbreeding.

atarwonders
A second advantage could be prevents the overproduction of proteins which could accumulate in the cell

what happens to the resulting protein in silent mutation or nonsense?

AnanyaSharma you do need to know the ATP numbers (you'll see this in practice exams), but I don't think it's necessary for the other compounds like NADH and FADH2 (although, it can be helpful to understand the processes of aerobic cellular respiration. Also, just to note, the new ATP numbers are 30 or 32 ATP for aerobic cellular respiration (2 for glycolysis, 2 for the Krebs cycle, and 26 or 28 for the electron transport chain). You also need to say "or" instead of "-" from what I've heard.

God Yeah one of them is to save energy and resources and prevent production of a gene product when its not needed
And the second is to produce sufficient quantities of a specific gene product ex- ATP synthase in muscle cells that undergo high rates off aerobic cellular respiration due to their large ATP requirement

yr12student22 In a silent mutation theres no change to the protein’s 3D tertiary structure as the single base substitution still codes for the same amino acid due to the degeneracy of the genetic code.
With missense although there’s a change of one amino acid- it does not entirely change the 3D tertiary protein structure due to misfolding as a result of different interactions between the variable R groups of amino acids in the polypeptide chain. This wont be as significant of an effect compared to framshifts where the protein becomes non functional

Hey guys, i am really struggling with natural selection and selective breeding. can someone please give me a example that summaries it.

yr12student22

the main difference is what is acting as the selection pressure.

For natural selection, take the example of grey and black moths in an environment, the selection pressure is the predators who may see the grey moths better when they are against darker bark on trees. This will allow for the moths to be 'fitter' since they are selected by their environment.

for artificial selection think of cows being bred to produce more meat. Humans are the selection pressure selecting more meaty cows to breed together. In the end, they aren't necessarily 'fitter'.

Do mutations or genetic drift have a greater effect on the gene pool?
Thanks

chemistry1111 Genetic drift since it tends to have a more profound and drastic effect on the gene pool, since the bottleneck effect wipes out much of a population and the founders effect can drastically reduce the gene pool its allele frequency due to migrating populations not genetically reflecting the many alleles found in the initial population (both populations, initial and founded, are usually greatly impacted). The effect of genetic drift can be even more pronounced in small populations, causing some to become extinct. Mutations occur all the time and are often quite small or random. Since they tend to only occur in one individual, they don't suddenly change the entire gene pool. Obviously, natural selection will alter the allele frequencies in response to a mutation and its possible advantages or disadvantages will alter the gene pool. However, you'd need a lot of mutations to have a sudden and drastic impact, and changes tend to occur gradually over time. Genetic drift is usually more sudden in its impact. The level of impact of mutations simply isn't the same as genetic drift tends to be. That said, I might be wrong, but that's sort of what I've been taught.

what's the relationship between the pathogen and antigen?

yr12student22 The antigen is a "body part" of the pathogen that your immune system recognises as foreign. Antigens can be proteins expressed by the pathogen, although there can be self-antigens produced by the body of someone affected by an autoimmune disease

what's the relationship between innate and inflammatory response?

atarwonders they consist of one big polypeptide (heavy chain) and one small polypeptide (light chain). They also have specific variable regions, which are complementary to the antigen. (the same as a normal antibody)

atarwonders Hi there! For this question the main point is about prior immunity so for 3 marks I’d say :—

1. The British population had been frequently exposed to the small pox virus before, whereas indigenous Australians were exposed to the small pox virus for the first time upon European arrival
2. Hence the indigenous Australians did not have any prior natural active immunity, and did not produce antibodies and memory cells against the small pox virus unlike the British
3. This caused the indigenous Australians to be more likely to experience severe symptoms of the viral infection causing a much greater number of deaths and infection cases than the British population
   (Make sure you use comparative statements here because it’s about the immunity of indigenous Australians VS the British population) hope this helps!

chemistry1111 Naive T cells undergo clonal expansion and selection to form cytotoxic T cells or memory T cells

What is the underlying difference between a rule based approach and consequences based approach?

Example would really be nice

spicynuggets
Consequences-based approach = Aims to maximise the positive outcomes while minimising the negative outcomes.

• Suggests that individuals should be driven by consideration for the consequences that are likely to result.
• Often emphasises the surrounding circumstances of an action, and may sometimes allow an individual to break the rules in order to achieve the greatest good for the greatest number of stakeholders.

Duty/rule-based approach = Promotes the responsibility of the agent above all else, and places importance on the duty of each individual.

• Suggests that individuals should be driven by a fundamental duty to act in a certain way.
• Aim is to follow set rules and responsibilities, with less regard for the consequences that may result.

Is rational drug design in the new study design?

Could someone please explain the function of the PAM sequence?

biology nope. That was from the last study design, so you can ignore these questions!

biology ok. So, the PAM sequence is a sequence of nucleotides called the protospacer adjacent motif (usually NNG, with N being any nucleotide). Viral DNA has many PAM sequences. When the protospacer is cut out of the viral DNA that has been injected into the bacteria, this is done a little after the PAM site by Cas1 and Cas2 (just other restriction endonucleases). The purpose of the PAM site is for the Cas9 cutting part of the CRISPR-Cas9 process. When the Cas9 enzymes identifies viral DNA and a PAM region on it, it opens up the DNA and sees whether or not the gRNA is complementary to the sequence of bases upstream from the PAM sequence but on the opposite strand. If the gRNA is complementary to the viral DNA section after the PAM sequence, it will cut the DNA on both strands just upstream from the PAM. However, if the gRNA does not match the viral sequence, Cas9 closes the viral DNA and continues to search for another PAM site (it can take multiple goes to find the right one since there are lots of PAM sites). So in summary, the PAM site is like a recognition tool or tag for Cas9 to search for and identify, allowing it to check the viral DNA with the gRNA before making a cut. Hope that makes sense!

_sophiestudies_ Thankyou so much!

for photosynthesis do you say the light dependent stage is the grana or thylakoid?

what is the role of rubisco?

clazah a granum is a stack of thylakoids, so u can say either i think

does anyone have access education biology exam

Is it okay to write exam in pencil