Hey all,
Hopefully you managed to have a go at the HSC homework questions from Monday. Here are the answers to them. As always, questions go out on a Monday and answers on a Friday.
2021 HSC biology multiple choice
The top response this week was 19 out of 20 in 12 minutes, so congratulations!
Biology
Here’s the interactive biology HSC 2020 multiple choice quiz
This 2019 HSC biology 5 mark question was answered fairly well in the responses that my students submitted.
Explain the loss of biodiversity that may result from TWO biotechnologies used in agriculture.
Artificial insemination involves collecting and manually injecting sperm into the female reproductive tract. This allows for selectively breeding two organisms of the same species with favourable traits. For example, impregnating a female cow, mare, without requiring the stallion, male cow, to be in the same location. Artificial insemination can increase biodiversity at the genetic level as it allows crosses that would not normally occur due to distance or physical differences. However, sperm from the same male often ends up being used many times leading to increased levels of these genes within the population i.e. decreased genetic diversity.
Transgenic species in agriculture initially increase genetic diversity by crossing genes from one species to another e.g. Bt cotton that has a gene from a bacteria to produce insect toxin. A disadvantage is that transgenic organisms are usually cloned which reduces biodiversity as it means large areas of crop are genetically identical. Additionally, gene flow from BT crops to normal native crops can lead to loss of non-transgenic species hence decreasing biodiversity.
Physics
This questions was poorly answered in 2016 for physics
B - contains a split ring commutator.
Chemistry
The following question is from 2016 HSC Q29 and is greater for chemistry calculation practice.
a) Deionised
b) 54.3%
Mathematics Advanced
A challenging multiple choice from the 2020 HSC math exam
D
Mathematics Extension
This question was surprisingly challenging for a lot of students in 2021 HSC
A is the answer
Really appreciate if you share with others to help us grow!
From,
Joshua Mills