Question

1. You use PCR analysis on DNA from a couple and their developing fetus to screen for a genetic defect. You find that both parents have one large and two small DNA bands, while the fetus has only the large DNA band. The most likely explanation for these results is :

1. The infant is a heterozygote and the parents are both homozygotes
2. All three are heterozygotes
3. Both parents are heterozygotes, the fetus is a homozygote
4. You can not tell the allele combinations for the three individuals

2. Linus Pauling and coworkers used gel electrophoresis of hemoglobin to:

1. Show that red cells have lots of hemoglobin
2. To show heterozygotes could be told apart from homozygotes for HbA and HbS
3. Show hemoglobin is made up of two subunits
4. Show that the a-globin and b-globin genes are linked

   3. Creighton and McClintock with Zea mays(corn) and Curt Stern with Drosophila both developed experiments that provided experiment backing to Morgan’s hypothesis of gene linkage on a chromosome. The key aspect of their experiments was:

5. They each looked at three traits on a single chromosome to prove gene linkage
6. They used chromosome with cytological markers (visible in a karyotype) at both ends
7. They used two traits one to each side of the centromere to show linkage
8. They used two traits one close to each ends of the chromosome to show linkage

Answer 1

Answer -2 Option(b) because he observed that Hb from anemic person has different velocity than a haemoglobin from a normal person. Answer-3 Option(