VCE Biology Questions Thread

lune777 so when mentioning gRNA or sgRNA When it is working naturally in bacteria you would say gRNA (that's when its acting as an adaptive immune system against invading pathogens) but when its used for gene editing for example in plants you would say sgRNA because its the sgRNA is synthetically made in labs. Hope that made sense

Mango If you look at past exams they always like to throw in questions about the inputs and outputs of both photosynthesis and cellular respiration

S007 I think also more than anything one of the bio tutors on atar notes said to like memorise model answers so just look through vcaa questions that are about CRISPR for example and just memorise the way they want the process to be said for example look at the citrus canker question from the 2023 biology exam I think it'll be helpful to try it out and then look at the answer and kind of get the gist of the way they want you to explain the process

sarah99 because its in charge of making a lot of trp so when its stoped from getting translated quite a few trp amino acids are not made so that means less trp is produced and basically the amount of trp is regulated therefore the bacteria can conserve energy. hope that answered ur q

If anyone could please answer any of these questions that would be a great help
1) Can only viruses of the same strain undergo antigenic shift? E.g. can it only be 2 influenza viruses from different organisms?
2) How do vestigial structures become non-functional?
3) If an organism migrates but doesn't interbreed with members of a new population, will it not affect the gene pool?
4) Does protein synthesis include folding into hierarchial structures or only transcription & translation?

Any help would be really greatly appreciated!!!!

1) so viruses from the same type can undergo antigenic shift. and it happens when two strains from the same type of virus but different strains infect the same host cell. and a new combination of the virus is made. Influenza is a common virus type that undergoes antigenic shift. When an influenza strain from one organism transfers to another organism this is called zoonosis and there is a high chance that the virus will undergo antigenic shift if that organism is also infected at that time and they both have different strains AND it infects the same host cell.

2) A structure can become vestigial when an organism is no longer subjected to the selection pressures that originally maintained its function. Over time, if the structure is no longer advantageous or necessary for survival due to changes in the environment or the development of a new, more efficient mechanism (through natural selection), it may lose its original function and become vestigial.

3) so emigration effects the gene pool. if an organism moves from a population, the population that it moved from will be affected (as an allele is lost so, that gene pool of that population will will therefore decrease as the genetic diversity decreased AND the gene pool is really affected especially when that organism had rare alleles) but the population that it moved to will not be affected unless if it does interbreed and produce a viable fertile offspring then yeah the genetic diversity will increase and that will play a role in the gene pool (basically bigger gene pool).

4) Yes, the folding of hierarchical structures is an essential part of protein synthesis and is specifically related to the process of a protein achieving its final functional form. After a protein is synthesized through translation, it undergoes a series of folding steps to acquire its proper three-dimensional structure (tertiary structure determines its function) which determines its function.

Thank you so much!! Really appreciate your in depth response - you really know your stuff !!

helloo I'm a bit confused as to why question 35 on 2023 NHT is D?

just curious which answer did you pick instead of D?

lune777

B cant be right bc animals in water existed before land animals

lune777 So they kinda did a trick to that question. It says ground surface at the top meaning that its the oldest and it makes sense that dinosaurs skull would be one of the oldest. And the really detailed fossil should be at the top as we can see it is the least decomposed as it has a lot of details to it compared to the other fossils shown.

sarah99 yeah i don't rlly get that one too lol

lune777 NOOO soorry my explantion wasnt clear its the youngest THE MOST DETAILED IS alwaysss the youngest REEMEMBER THAT. and the question flipped the layers sort of by ground surface they mean the lowest layer and then u go up (but in the question ur going down) so they basically try to trick people. i hope this made more sense.