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Pseudogenes are the remains of broken genes which are unable to function and can be considered to be genetic fossils - VCE - SSCE Biology - Question 8 - 2007 - Paper 1
Question 8
Pseudogenes are the remains of broken genes which are unable to function and can be considered to be genetic fossils. Some are relics of genes lost through evolution... show full transcript
Worked Solution & Example Answer:Pseudogenes are the remains of broken genes which are unable to function and can be considered to be genetic fossils - VCE - SSCE Biology - Question 8 - 2007 - Paper 1
Step 1
a. What is one possible consequence of the loss of gene G in primates?
Answer
The loss of gene G in primates may lead to an inability to synthesize Vitamin C, which means that these organisms must obtain this essential vitamin through their diet, rather than being able to produce it endogenously.
Step 2
b. From the graph, what can be concluded about the importance of smell to the survival of these four groups?
Answer
From the graph, it can be concluded that smell is most important to dogs and mice, while it appears to be less crucial for apes and humans. This suggests that the evolutionary pressures related to smell may have differed among these species.
Step 3
c. Would you expect to find any change in the numbers of smell pseudogenes in apes and monkeys able to distinguish colours? Explain why.
Answer
Yes, it is expected that apes and monkeys that can distinguish colours may have a higher number of functional smell receptor genes compared to those that cannot. This is because the ability to distinguish colours might correlate with a more refined sense of smell, leading to the preservation of essential genes that contribute to olfactory functions.
Step 4
d. Why are pseudogenes able to accumulate mutations that do not exist in functional genes?
Answer
Pseudogenes are non-functional segments of DNA that arise from the decay of functional genes. Since they no longer code for proteins, mutations in their sequences do not affect the organism's phenotype. This provides a relaxed selection pressure, allowing these pseudogenes to accumulate a variety of mutations over time without negative consequences.