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?
In which stage of mitosis is the cell labelled X ?
Which sex chromosome(s) can be found in a human ovum?
Which of the following is an inherited disease that is due to a base substitution mutation in a gene?
The leaves of rice (Oryza sativa) may contain some vitamin A or its precursor beta-carotene, but in the edible rice grain this nutrient is not produced due to the absence of four enzymes required in the pathway. Using Agrobacterium tumefaciens as a vector, scientists successfully inserted genes into the beta-carotene pathway (two genes from daffodil and one gene from a bacterium) which allowed the rice grains to produce beta-carotene. They called this genetically modified plant Golden rice.
Identify the protein for which Gene 1 from daffodil codes.
Outline how the scientists would determine whether Gene 2 from daffodil had been taken up successfully by rice DNA.
Explain how Agrobacterium tumefaciens is used to produce genetically modified crop plants.
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?
Which characteristics are used to identify chromosomes when constructing a karyotype?
I. The length of the chromosome. II. The position of the centromere on the chromosome. III. The pattern of bands on the chromosome. IV. The position of the chromosome on the spindle.
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?
Which of the following involves complementary base pairing?
I. Transcription II. Translation III. Replication IV. Denaturation
Down syndrome can be detected before birth by chorionic villus sampling. From where are the cells for this test taken?