A diseased man marries a normal woman. They get three daughters and five sons. All the daughters were diseased and the sons were normal. The gene of this disease is:
1. Sex-linked dominant
2. Sex-linked recessive
3. Sex-limited character
4. Autosomal dominant
Which of the following discoveries resulted in a Nobel Prize:
1. X-rays induce sex-linked recessive lethal mutations
2. Cytoplasmic inheritance
3. Recombination of linked genes
4. Genetic engineering
The recessive genes located on X-chromosomes in humans are always:
1. Sub-lethal
2. Expressed in males
3. Expressed in females
4. Lethal