Question

1.1) Which of the genes control development in Drosophila through the regulation of the expression of other genes? (can select more than one)

a) TATA‑box genes

b)egg‑polarity genes

c) homeobox genes

d) segmentation genes

e)MADS‑box genes

1.2 ) Which statements about apoptosis, or programmed cell death, is incorrect?

a)it is controlled by genes that can be activated in most cells

b)it is distinct from necrosis

c) it results in the spillage of cell contents

d) it is a normal part of development

e) it can be inactivated in some cancers

1.3 ) Select the reason that best describes how the immune system responds to the nearly endless variety of nonnative antigens with only a limited set of genes.

a)Error‑prone ribosomes present in B cells allow for higher rates of protein diversity.

b)Recombination occurs within the genes that encode antibodies in each B cell.

c) Differential expression of antibody‑encoding genes results in antibody variability.

d) Diverse chaperone proteins encourage alternative folding of antibody tertiary structure.

Answer 1

1.1 Both options c and e are correct. Homeotic genes and MAD box genes help in controlling regulation of other genes in Drosophila. Homeotic genes regulate the development of anatomical structures whereas MAD box genes regulate embryogenesis in Drosophila.

1.2 The statement which is incorrect about apoptosis is option a i.e. it is controlled by genes that can be activated in most cells. Apoptosis is programmed cell death and is under strict control and regulations. Some specific genes responsible for apoptosis are activated in specific cells which is strictly controlled.

1.3 The correct answer is option b i.e. Recombination occurs within the genes that encode antibodies in each B cell. Antibody diversity is achieved via rearrangements of B cells through site specific genetic recombination.