In this problem we will explore some of the many ways that mutations in two different genes can interact to produce different Mendelian ratios. Consider a hypothetical insect species that has red eyes. Imagine mutations in two different unlinked genes that can, in certain combinations, block the formation of red eye pigment yielding mutants with white eyes. In principle, there are two different possible arrangements for two biochemical steps responsible for the formation of red eye pigment. The two genes might act in series such that a mutation in either gene would block the formation of red pigment. Alternatively, the two genes could act in parallel such that mutations in both genes would be required to block the formation of red pigment.

Further complexity arises from the possibility that mutations in either gene that lead to a block in enzymatic activity could be either dominant or recessive. If the crosses is made between a wild type insect with red eyes and a true breeding white eyed strain with mutations in both genes. Such considerations yield the Pathways in parallel with recessive mutations in both genes, determine the phenotype of the F1 progeny and the expected phenotypic ratio of red to white eyed insects in the F2.

#Question id: 67

#SCPH06 I Botany

When a region of DNA must be repaired by removing and replacing some of the nucleotides, what ensures that the new nucleotides are in the correct sequence?

#Question id: 68

#SCPH05 I Biotechnology

Match the following functional groups given in column I with their respective representatives given in column II.

COLUMN I               COLUMN II

1. Anhydride               a. RCOOR

2. Ether                       b. ROCOCH3

3. Acetyl                     c. ROR

4. Amido                     d. RCOOCOR

5. Ester                        e. RCONH2

#Question id: 68

#SCPH06 I Botany

Match the following functional groups given in column I with their respective representatives given in column II.

COLUMN I               COLUMN II

1. Anhydride               a. RCOOR

2. Ether                       b. ROCOCH3

3. Acetyl                     c. ROR

4. Amido                     d. RCOOCOR

5. Ester                        e. RCONH2

#Question id: 69

#SCPH05 I Biotechnology

Which of the following is the diastereomer of the following compound?

#Question id: 69

#SCPH06 I Botany

Which of the following is the diastereomer of the following compound?

#Question id: 70

#SCPH05 I Biotechnology

The dimensions of living cells are limited, on the lower end by the minimum number of biomolecules necessary for function, and on the upper end by the rate of diffusion of solutes such as oxygen. Except for highly elongated cells, they usually have lengths and diameters in the range of