The number of different phenotypes that would be expected in the offspring of a cross between plant 1 and plant 2 is:
A - VCE - SSCE Biology - Question 30 - 2014 - Paper 1
Question 30
The number of different phenotypes that would be expected in the offspring of a cross between plant 1 and plant 2 is:
A. 2
B. 4
C. 6
D. 8
Worked Solution & Example Answer:The number of different phenotypes that would be expected in the offspring of a cross between plant 1 and plant 2 is:
A - VCE - SSCE Biology - Question 30 - 2014 - Paper 1
Step 1
Determine the cross of plant 1 and plant 2
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Answer
To calculate the number of different phenotypes resulting from the cross between two plants, we often look at the genetic makeup of the plants in question. Typically, this involves understanding whether each plant is homozygous or heterozygous for the traits being considered.
Step 2
Analyze the genotypes
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Answer
Assuming plant 1 has genotype Aa and plant 2 also has genotype Aa, where 'A' and 'a' represent different alleles of the same gene, we can use a Punnett square to find the possible combinations in their offspring.
Step 3
Construct the Punnett square
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Answer
The Punnett square for Aa x Aa would yield the following combinations:
AA (homozygous dominant)
Aa (heterozygous)
aa (homozygous recessive)
This results in 3 distinct genotypes.
Step 4
Count the phenotypes
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Answer
In this scenario, both AA and Aa display the dominant phenotype, while aa displays the recessive phenotype. Thus, we expect 2 distinct phenotypes from this cross: dominant and recessive.
Step 5
Final consideration
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Answer
However, if there are multiple traits or more complex inheritance patterns involved, the number of phenotypes could be higher. But based on typical monohybrid crosses, the expected answer would be 4 phenotypes, with some considering variations if multiple traits are involved.
