BLG1501 Assignment 2 Semester 1 2026 (Answer Guide) 641006 – Due April 20 2026

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BLG1501 Assignment 2 Semester 1 2026 (Answer Guide) 641006 –
Due April 20 2026
VERIFIED AND CERTIFIED ANSWERS. WRITTEN IN REQUIRED FORMAT AND WITHIN
GIVEN GUIDELINES. IT IS GOOD TO USE AS A GUIDE AND FOR REFERENCE, NEVER
PLAGARIZE. Thank you and success in your academics.
UNISA, 2026




QUESTION 1

Monohybrid Cross Between a Purple Homozygous Flower and a White
Homozygous Flower

In this question, purple flower colour (P) is dominant over white flower colour (p). This
means that the allele P will mask the expression of p whenever both are present in a
heterozygous individual (Reece et al., 2018).

A homozygous purple flower therefore has the genotype PP, while a homozygous
white flower has the genotype pp.

Step 1: Parental (P) Generation

Purple homozygote × White homozygote

Genotypes:

PP × pp

The purple parent can only produce gametes carrying the allele P, while the white
parent can only produce gametes carrying the allele p.

Gametes:

 PP → P, P

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 pp → p, p

Step 2: F₁ Generation (First Filial Generation)

Using a Punnett square:


P P
p Pp Pp
p Pp Pp


All offspring have the genotype Pp.

Genotypic ratio (F₁)

100% Pp

Phenotypic ratio (F₁)

100% Purple flowers

This occurs because purple (P) is dominant over white (p), so even though the offspring
carry one recessive allele, it is not expressed (Mader, 2019).

Step 3: F₂ Generation

To determine the F₂ generation, we cross two F₁ individuals:

Pp × Pp

Each parent can produce two types of gametes: P and p.

Punnett square:


P p
P PP Pp