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Can someone mark this for me? (1 Viewer)


New Member
May 28, 2018
I'm doing practice questions for Bio when I came across this one;

"Most offspring resemble their parents in a number of characteristics, but there are
often some characteristics in the offspring that are unexpected.

Explain, using examples, how genetics and the environment can affect the phenotype
of individuals."

It is worth 8 marks and this was my response in exam like conditions

Genetics and the environment directly affect the phenotype of an organism, as natural variation is a derivative of both factors.
Environmental factors can directly affect the phenotypical expression of an organism. If a person is exposed to radiation that is ionising in nature, their DNA sequences can be altered via the deletion of a base in their genome. When an affected indivudal gives birth, the childs genome will be mutated and this can lead to incorrect amino acid sequences that will result in the production of incorectly functioning proteins, thereby giving rise to abnormalities. For example, indivduals exposed to radiation during the cherynobyl incident have produced children with severe abnormalities and limited functioning as a direct result of radiation.

Variation is a result of inherited genetics as meiosis and fertilisation involve processes that produce variations within offspring. During meiosis, homologous chromosomes will overlap and interchange genetic information, increasing the variability in the chromosomes. After this and during Meiosis I, chromosomes will independently assort into two new cells, it is completely random what chromosome goes into what cell, thereby increasing variation again. In Meiosis II, random segregation occurs, chromosomes will seperate randomly into 4 gamete cells, this increases variation as there is no way of telling what chromosome will be in each gamete. Overall millions of gametes will be produced, and it is completely random what two will come together during fertilisation. Because of these processes, offspring will exhibit different phenotypes to their parents.

If someone could read over and give me some feedback, that would be awesome!


Sep 12, 2018
Sure! Awesome answer overall. I would give you 6 out of 8 if I was sticking to the marking guidelines.

There are multiple learning objectives incorporated in this question, a total of 7 for 8 marks.

One of them is getting you to define the term 'phenotype' as it is the main keyword of the question.

Another learning objective is the explain the concept of recessive genes (briefly) from the first line.

There are 5 other learning objectives embedded in this question which you have identified and addressed. Just include your response to the 2 learning objectives that you missed and you will get 100%! Well done!
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