Answer:
Explanation:
For number 4, it tells you that purple body color is dominant to blue.
When an allele is dominant over another allele (alleles are different forms of genes, represented using letters) that means only one dominant allele needs to be present to express the dominant phenotype (phenotype is the physical appearance determined by genotype). Since purple is dominant, we use a capital "P" to represent it. Since blue is not dominant, it is called recessive, so we use a lower-case "p" to represent it.
The first genotype they give you, it is "PP", and since at least one big P is there, the phenotype is purple.
The second genotype they give you is "Pp", and since there is at least one capital P, the phenotype is also purple. It does not matter that the second allele is a lower-case, because as long as there is a capital P present, it will masks the presence of the lower-case (recessive) allele.
The third genotype is "pp", both are lower-case, so there is not dominant allele to mask the recessive ones. So, the phenotype is blue. The recessive phenotype will only be phenotypically present if the genotype is homozygous recessive.
Homozygous - having both of the same alleles (PP or pp)
In which PP is known as homozygous dominant, because it is made from the dominant allele. And pp is known as homozygous recessive, because it is made from the recessive allele.
Heterozygous - having one dominant and one recessive allele (Pp)
Note: It does that really matter what letter you use, the importance is whether it is a capital or not because that tells you if it is dominant or recessive.
The same for square shape. It says that square is dominant over round, so a capital letter is used to represent square (S), and a lower-case to represent round (s).
Therefore, the phenotype would be:
Square, Square, round, respectively.
Number 5 is asking you to go from the phenotype (physical look) to the genotype.
Tall head is (T) and dominant to short (t).
Tall = could be PP or Pp (homozygous dominant or heterozygous). It could be both since in both genotypes at least one dominant allele is present, so it will result in a dominant phenotype.
Short = tt. It is "tt" because it is recessive, and the only way to physically show the recessive phenotype is to have a homozygous recessive genotype.
Green is dominant over blue, so again.
Green body - the genotypes could be GG or Gg. At long as there is one capital (dominant) allele.
Yellow body - gg (it is recessive, so it cannot have a capital "G", or that would masks the recessive g).
Hope this helps.
