In pea plants, purple flowers are dominant over white flowers. The phenotype ratio of purple to white flowers in a population of
five plants is 4:1. How many plants have white flowers? 1
2
4
5
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In some lizard species, a short tail is recessive and a long tail is dominant. According to the principle of dominance:
a lizard with a TT genotype will have a short tail
a lizard with a tt genotype will have a long tail
a lizard with a Tt genotype will have a short tail
a lizard with a tt genotype will have a short tail
1. 1 Since the ratio is purple flowers to white flowers, and the ratio is 4:1 out of 5 plants, there is 1 white flower. Remember that, in a ratio, the first number is the first one mentioned, and the second number is the second one mentioned.
2. A lizard with a tt genotype with have a short tail Since the short tail is recessive, it can be represented with a lowercase letter (t), and since the long tail is dominant, it can be represented with a capital letter (T). Because the long tail gene is dominant, if even one capital T is present in a genotype, the lizard will have a long tail. You can label the different kinds of genotypes if it helps.
TT - long tail, since both genes are for a long tail Tt - long tail, since one gene is for a long tail, and the long tail is dominant tt - short tail, since both genes are for a short tail
