Photo AI
Long before the development of agricultural crops, hunter-gatherers in southern Africa would pick the tastiest nutty fruits of the marula tree and scatter them around their camps - VCE - SSCE Biology - Question 9 - 2010 - Paper 1
Question 9
Long before the development of agricultural crops, hunter-gatherers in southern Africa would pick the tastiest nutty fruits of the marula tree and scatter them aroun... show full transcript
Worked Solution & Example Answer:Long before the development of agricultural crops, hunter-gatherers in southern Africa would pick the tastiest nutty fruits of the marula tree and scatter them around their camps - VCE - SSCE Biology - Question 9 - 2010 - Paper 1
Step 1
Explain how this practice is an example of selective breeding.
Answer
This practice exemplifies selective breeding as humans choose the best-producing marula trees based on their fruit quality. The selective agent in this case is the humans who, through their choices, decide which trees to cultivate. The phenotypic characteristic being acted upon is the taste and nutritional quality of the fruits, as tastier fruits are selected for propagation.
Step 2
What can you infer about the genotype of trees propagated through marcotting?
Answer
The genotype of trees propagated through marcotting is identical or nearly identical since marcotting involves cloning a branch from an existing tree. This means that the plants are genetically identical or clones, representing a pure breeding genotype.
Step 3
Outline one disadvantage of a plantation of marula trees grown through marcotting compared to a natural population of marula trees.
Answer
One major disadvantage is the lack of genetic diversity. In a plantation of marula trees grown through marcotting, should a disease occur, the entire plantation may be susceptible to the same disease due to the identical genetic makeup, potentially leading to total loss. In contrast, a natural population would likely have a greater variety of genotypes, some of which may have resistance to specific diseases.
Step 4
Should the fruit from marcotted marula trees be labelled as genetically modified (GM)? Explain why.
Answer
The fruit from marcotted marula trees should not be labelled as genetically modified because marcotting is a form of asexual reproduction that does not alter the genes of the plant. There has been no genetic alteration; rather, the process involves simply propagating a plant through cloning without introducing foreign DNA or altering the genetic structure.