To discover whether an animal showing the dominant trait is homozygous or heterozygous, it must be crossed with an animal that is:

Two tall pea plants are crossed, producing 105 tall plants & 32 short plants. The genotypes of the tall parent plants are:

A spotted dalmation is mated with a pure-white dalmation (ss) to deteremine whether its genotype is SS or Ss for spots. Three puppies are born, all with spots. We can conclude that the spotted dalmation is SS.

In mice brown (B) is dominant to white (b). A brown mouse is mated with a white mouse. Twelve brown mice are produced. The brown mouse's genotype is:

Two brown-eyed parents have a child with blue eyes. The best explanation is:

Which scenario best supports the conclusion that a black guinea pig's genotype is homozygous dominant?

Individuals with the same phenotype have the same genotype

In a test cross to determine whether a fruit fly is homozygous (WW) or heterozygous (Ww) for long wings, 7 long-winged flies & 1 short winged-fly are produced. Which is a valid conclusion?

In hamsters, long tails (L) are dominant to short tails (l). A student wishes to perform a test cross to determine whether a female long-tailed hamster is homozygous or heterozygous for tail length. She mates the hamster with a male long-tailed hamster & studies the offspring, which are 100% long-tailed. She concludes that the female hamster's genotype is "LL". What mistake(s) did the student make?

In African-violet plants, purple flowers are dominant to white flowers. You purchase an African-violet plant with white flowers. It's genotype could be represented as :