What is the definition of an allele?

A gene is...

What is the law of dominance?

What is the definition of heterozygous?

In cats, the allele for stripes (S) is dominant over the allele for no stripes (s). Two heterozygous cats are bred. If the female cat has a litter of 8, predict how many kittens will have no stripes.

In guinea pigs, the allele for short hair (H) is dominant and the allele for long hair (h) is recessive. When a dominant homozygous male and a heterozygous female are bred together, what is the predicted phenotypic ratio for the offspring?

What word is used to describe a thread-like structure of DNA that carries genes?

When carrying out a test cross, what is the organism of unknown genotype always crossed with?

Cystic fibrosis is a lung disease caused by a recessive allele, c.

Two healthy parents produce a child with cystic fibrosis.

Which of the following statements must be true?

Which process involves meiosis?

State the genotype of person P

A man of genotype I^AI^o and woman of genotype I^BI^o have a child.

What is the chance that the child will have the same blood group as one of its parents?

Which of the following statements are true of codominance?

I. Both alleles are expressed in a person who is heterozygous

II. More than two phenotypes are usually possible

III. The ABO blood group system is an example of it

Gary and Fiona are both healthy but produce a child with a genetic disease caused by a recessive allele.

Which of the following must be true?

Albinism is humans us caused by a recessive allele. It causes the skin and hair to appear white.

Parents who do not have this condition produce a child with abinism.

What is the probability that their second child will be born with albinism?

The pedigree chart shows the inheritance of a genetic disorder in a family.

What conclusion can be made about this genetic disease?

Which of the following genotypes are possible for a person of blood group A?

I. I^A I^A

II. I^A I^B

III. I^A I^O

Coat colour in a certain mammal is determined by two codominant alleles of a gene.

Allele B produces a black coat and allele W produces a white coat.

What would you expect the phenotype to be of a mammal who is heterozygous for this gene?

Patrick is blood group AB.

Samantha is blood group A. However, her father was blood group O.

They have a child.

What is the probability that this child has the same blood group as Patrick or Samantha?

In a certain plant, the allele fo white fruit (W) is dominant over the allele for yellow fruit (w).

A white-fruited plant was crossed with a yellow-fruited plant.

About half of the offspring were white-fruited and the other half were yellow-fruited.

Which genotypes did the parent plants have?

The pedigree chart shows the inheritance of a genetic disorder in a family.

It is caused by a recessive allele.

Which person in this pedigree chart has two possible genotypes?

The diagram shows the inheritance of coat colour in pigs through three generations.

What is the most likely explanation of how coat colour in pigs is inherited?

I. codominant alleles are involved

II. sandy pigs are heterozygous

III. the allele for a red coat is dominant

One alternative form of a gene is called_______________

this image is an example of

What term is used to describe the alleles that a person carries for a gene

Which of the following is true of a recessive allele?

I. it is only expressed if the dominant allele is absent

II. two copies are needed to show its feature

III. it always causes a genetic disease

How many alleles for each gene are carried in the sex cells (gametes)?

Tall (T) is dominant over dwarf (t) in a species of plant. A tall plant has an unknown genotype. Which plant should it be crossed with to ascertain this?

A brown eyed man of genotype Bb marries a blue eyed woman. What is the chance that their third child is brown eyed?

A couple has 6 children but of them, 5 were boys. What reason explains why this deviates from the expected 3 boys : 3 girls ratio?

A couple has had 1 child, who is a boy. Which of the following statements is true?

Coat color in a dog breed is determined by incomplete dominance where three colors are produced (Brown, tan and white), and the brown coat allele (B) has incomplete dominance over the white coat allele (b). Which offspring ratio would be expected from a cross between a brown dog and a white dog?

Human blood type is determined by multiple alleles (A, B, and O). Which ratio would result from a cross between a man with Type AB blood and a woman with Type O blood?