Introduction to Genetics

Which statement describes Mendel's hypotheses regarding gametes?

A gamete carries one allele for a gene.

Why did Gregor Mendel use peas in his experiments?

Peas have characteristics that have two forms.

The table below summarizes Mendel's results for the F2 generation. What number should replace the letter x in the "Seed color" row?

2,001

The flowchart below shows the three generations of a cross between a pea plant that has yellow pods and a pea plant that has green pods. Yellow pods are the dominant trait. The flowchart is missing the labels that describe the traits. In which squares should the phrase "Yellow pods" appear?

A, C, and D

If Mendel had crossed a true breeding dominant plant with a true breeding recessive plant, in which of the three generations is the recessive trait visible?

P generation and F2 generation

Cystic fibrosis is a genetic disorder. It is a recessive trait that is determined by two alleles. Suppose two parents each carry at least one recessive allele, but neither of them has cystic fibrosis. Which statement reflects the likelihood of a child of these parents having cystic fibrosis?

The child may or may not have the disease because a recessive gene from each parent may be passed on.

During an experiment, a scientist crosses a pea plant that has purple flowers with a pea plant that has white flowers. The plants that result from this cross in the F1 generation have both purple and white flowers. What can the scientist conclude?

The plants in the P generation were not true-breeding.

The table below summarizes the traits that Mendel examined during his experiments. What do these characteristics all have in common?

They can all be easily observed.

Scientists often use fruit flies as a method to test hypotheses about human genes. Why are fruit flies advantageous in the study of human inheritance?

They reproduce quickly and take up little space.

Mendel was able to study seven traits in all the pea plants in each generation. Which of his hypotheses allowed him to analyze each trait separately?

When gametes are formed, each gamete carries only one allele for the gene.

Nucleic acids offer variability because they contain alternate forms of genes called _____.

alleles

Mendel's pea plants had either purple or white flowers. This means that the plants

have two alleles for the gene.

What controls traits and inheritance?

nucleic acids

Which has the most control of traits and inheritance?

nucleic acids