What are all the possible phenotypes of children born to a mother with blood group AB and a father with blood group A?

What technique was used by John Cairns to measure the length of the DNA molecule in Escherichia coli?

Two restriction endonucleases (EcoRI and BamHI) were used to cut a DNA sample into smaller fragments. These were then subjected to gel electrophoresis and the results are shown. The lengths of the DNA fragments are measured in kilobases (kb). One kilobase is 1000 DNA bases.

Which statement is supported by the data?

In cats, black coat colour is dominant over gray. A female black cat, whose mother is gray, mates with a gray male. What is the predicted ratio of phenotypes in the offspring?

Creeper in chickens is a condition in which the chickens are born with very short legs. The creeper allele (C) is dominant over the normal allele (c). Embryos which are homozygous for the dominant allele fail to develop into viable chickens and die before they hatch. What phenotypic ratio would you expect in the live offspring of a cross between two creeper chickens?

Huntington’s disease is an autosomal dominant genetic disease. What are the chances of two parents that are heterozygous for the gene having a child with Huntington’s disease?

Down syndrome can be detected before birth by chorionic villus sampling. From where are the cells for this test taken?

Which technique is used to amplify very small samples of DNA?

Which is a characteristic of the pairs of sister chromatids that are visible during meiosis?