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The student recorded the weight of over 10000 bean seeds and graphically presented the data as shown below - VCE - SSCE Biology - Question 26 - 2014 - Paper 1
Question 26
The student recorded the weight of over 10000 bean seeds and graphically presented the data as shown below. The seeds came from bean plants grown in identical enviro... show full transcript
Worked Solution & Example Answer:The student recorded the weight of over 10000 bean seeds and graphically presented the data as shown below - VCE - SSCE Biology - Question 26 - 2014 - Paper 1
Step 1
Explain how seed weight varies because all bean plants are homozygous for seed weight.
Answer
Homozygosity in plants means that both alleles for seed weight are identical. This results in a uniform expression of the trait, leading to consistently similar seed weights across the population. As a result, there is reduced variation in seed weight since all seeds will express this specific characteristic uniformly.
Step 2
Explain how seed weight varies because many genes contribute to determining the weight of the seed.
Answer
Seed weight is a polygenic trait, meaning it is influenced by multiple genes. Each gene can have a small effect on the phenotype, and their interactions can create a range of seed weights. This genetic architecture leads to variation in seed weight among different plants, as the combination of alleles inherited can produce diverse phenotypes.
Step 3
Explain how seed weight varies because the bean plants grew in soil with similar moisture content.
Answer
When the bean plants are grown in soil with similar moisture content, it helps limit environmental variation that could affect seed weight. Consistent moisture levels ensure that all plants receive adequate water, leading to more uniform growth conditions. However, while it reduces variability from water stress, it doesn’t eliminate genetic variability, which can still influence seed weight.
Step 4
Explain how seed weight varies because the bean plants grew at different temperatures.
Answer
Temperature is a crucial environmental factor that can influence plant growth and seed development. Different temperatures can affect metabolic rates, nutrient uptake, and overall plant health, leading to variations in seed weight. For example, higher temperatures may accelerate growth but could also stress the plants, resulting in smaller or lighter seeds, while optimal temperatures may promote healthy development leading to heavier seeds.