MCQ-5: Inheritance

A pure-breeding white rat was crossed with a pure-breeding black rat. All their offspring were black.
One of the offspring was bred with a pure-breeding white rat.
What is the most likely percentage of black rats in the offspring?

An organism is heterozygous for a gene with the alleles T and t.
Which diagram represents a diploid cell from this organism?

Red-green colour blindness is a sex-linked characteristic caused by a recessive allele.
Which prediction can be made about the children of a woman who is colour-blind and a man with normal vision?

What is the role of mRNA?

The diagram shows the formation of new diploid cells.

What do arrows X and Y represent?

A man marries a woman who has a different blood group from him. They have two children. The children have different blood groups from each other and different blood groups from their parents.
What are the genotypes of the parent’s blood groups?

Sickle-cell anaemia is a genetic disease that is caused by the allele Hb^S.
Hb^A is the normal allele.
A woman does not have the symptoms of the disease but her brother does show symptoms.
If her mother and father do not have symptoms, which statement is correct?

A sperm cell from a domestic cat contains 19 chromosomes.
If this cell fertilises an egg, which zygote is produced?

The diagram shows a cell of an organism. The nucleus contains 12 chromosomes.

After it divides by mitosis, how many chromosomes would be present in one of the daughter cells?

Pure-breeding black-feathered chickens are mated with pure-breeding white-feathered chickens. All of the individuals in the offspring in the F1 generation have both black and white feathers.
What will be the ratio of offspring phenotypes when two of the F1 generation chickens are crossed?

Which name is given to different versions of a gene?

Which feature of meiosis ensures that the zygote is diploid?

Which genotypes result in a person having blood group A?

How many chromosomes are there in each of the human cells shown in the table?

The diagram shows a diploid cell and alleles R and r on one pair of chromosomes.

When this cell divides by mitosis, which daughter cells will be produced?

The diagram shows breeding rats where the allele for grey fur is dominant to white fur.

Which two individuals are definitely heterozygous for fur colour?

The diagram shows a genetic cross between a male bird with black feathers and a female bird with white feathers. All of the offspring have blue feathers.

Two of the blue offspring are crossed.
Which row shows the correct phenotype percentages for the cross?

A haploid nucleus is defined as one that contains

Sickle-cell anaemia is caused by a mutation in the haemoglobin gene.
The normal base sequence is shown in 1, and the sickle-cell base sequence is shown in 2.

1. TGA GGA CTC CTC
2. TGA GGA CAC CTC

What causes the change in the DNA?

In cats, the allele for short hair is dominant to the allele for long hair. A short-haired cat gives birth to five kittens. Two of them have long hair.
Which statement must be correct?