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In a species of mammal, two inherited phenotypes exist – spiky hair and smooth hair - VCE - SSCE Biology - Question 3 - 2011 - Paper 1
Question 3
In a species of mammal, two inherited phenotypes exist – spiky hair and smooth hair. A scientist set out to produce a clone of a spiky-haired male (organism M). a. ... show full transcript
Worked Solution & Example Answer:In a species of mammal, two inherited phenotypes exist – spiky hair and smooth hair - VCE - SSCE Biology - Question 3 - 2011 - Paper 1
Step 1
a. i. Which living cell from male M would provide the nucleus to start this procedure – one of its somatic cells or one of its sperm cells?
Answer
The nucleus should be taken from one of the somatic cells of male M. Somatic cells are diploid and contain two sets of chromosomes, including the genes responsible for the spiky-haired phenotype, making them suitable for cloning.
Step 2
a. ii. Explain your answer.
Answer
Somatic cells contain a complete set of chromosomes, including all necessary genetic information for producing an individual, whereas sperm cells are haploid and only carry half of the organism's genetic information. Therefore, using a somatic cell nucleus ensures that the clone will have the full genetic complement required to express the spiky-haired trait.
Step 3
b. i. What procedure must this egg undergo before the nucleus from organism M is added?
Answer
Before the nucleus from organism M is added, the egg must undergo enucleation, which is the removal of its nucleus. This is essential to ensure that the genetic material from the egg does not interfere with that from the donor organism M.
Step 4
b. ii. Explain why this procedure must occur.
Answer
This procedure must occur to prevent the egg's genetic material from contributing to the development of the clone. By removing the egg's nucleus, the resulting zygote will only have the genetic information from the somatic cell of organism M, ensuring that the clone develops with the intended phenotype without any influence from the egg cell's genetics.
Step 5
c. Which of the three organisms – M, P or R – will the cloned organism most closely resemble in terms of all other traits?
Answer
The cloned organism will most closely resemble organism M in terms of all traits. Since the clone is created using the somatic cell nucleus from organism M, it inherits the complete genetic makeup from M. Organism P contributes only maternal factors through the egg but does not contribute the fundamental genetic information.