This set of Cell Biology Multiple Choice Questions & Answers (MCQs) focuses on “Gene Expression Control – Processing-level Control”.
1. Which of the following is not a proximal promoter element?
Explanation: There are three proximal promoter elements TATA, CAAT and GC boxes. They are called so because of their presence at 100 to 150 base pairs upstream from the gene.
2. Deletion maps are used to determine sites in the genome which interact with ___________________
a) transcription factors
Explanation: Deletion maps are used by the researchers to determine which sites in the genome interact with a particular transcription factor. In this procedure, cells are transfected with altered DNA molecules that contain deletions.
3. Which type of enzymes is used in DNA footprinting?
a) RNA-digesting enzymes
b) RNA polymerases
c) DNA polymerases
d) DNA-digesting enzymes
Explanation: DNA-digesting enzymes are used in DNA footprinting to determine the genetic sequences that are protected by transcription factors. The basic principle of the technique is that when transcription factors bind to a particular sequence, it protects the sequence from digestion by nucleases.
4. Which enzyme is used to kill the cells in genome-wide location analysis?
Explanation: Genome-wide analysis is the technique used to simultaneously monitor all the sites in the genome that carry out a particular activity. Formaldehyde is used to kill the cells and cross-link the transcription factors.
5. Chromatin immuno-precipitation is induced by _____________________
Explanation: Chromatin immuno-precipitation (also known as ChIP) is induced by the addition of antibodies specific for transcription factors. The technique can be used to detect which antibodies bind to which DNA sequences.
6. Microarrays used in the ChIP experiments contain non-coding DNA.
Explanation: Microarrays used in the chromatin immuno-precipitation contain DNA sequences prepared from the intergenic sequences. Intergenic sequences are the non-coding, regulatory regions of the genetic sequence.
7. Analogues of glucocorticoids are prescribed as ________________ agents.
Explanation: Glucocorticoids are a group of steroid hormones, synthesized by the adrenal gland. Analogues of glucocorticoids such as prednisolone are prescribed as anti-inflammatory agents.
8. Glucocorticoids are released during periods of __________________
c) climate change
Explanation: Glucocorticoids are released during periods of stress and physical injury. To be able to respond to these hormones, a cell must contain specific receptors called the glucocorticoid receptor (GR).
9. Expression of genes is also regulated by distant DNA elements called _________________
Explanation: In addition to proximal and distant promoter elements, expression of genes is also controlled by distant DNA elements called enhancers that extend 200 base pairs in length.
10. Which of the following majorly influences the activity of genes during early mammalian development?
a) temperature changes
Explanation: Whether a gene remains active or inactive during mammalian development depends solely on whether they were brought into the zygote by egg or sperm.
11. Prader-Willi syndrome (PWS) is caused due to disturbances in which of the following chromosomes?
Explanation: Prader-Willi syndrome (PWS) is an inherited neurological disorder caused due to a deletion in the imprinted genes of chromosome 15 inherited from the father. It is characterized by mental retardation, obesity and underdevelopment of gonads.
12. A single gene can encode two or more related proteins by the process of _________________
a) gene silencing
b) alternative splicing
Explanation: Alternative splicing regulates gene expression at the level of RNA processing. It helps a gene encode more two or more related proteins.
13. RNA editing is the mechanism in which specific amino acids are converted after _______________
Explanation: RNA editing is the process taking place after the RNA is transcribed where specific nucleotides are converted to other nucleotides, generating amino acid substitutions.
14. RNA editing is particularly important in the ________________
a) digestive system
b) reproductive system
c) nervous system
d) circulatory system
Explanation: RNA editing is not as widespread as alternative splicing but it is particularly important in nervous system. A significant number of neural messages have one or more adenines converted to inosines.
15. Which of the following products of RNA editing plays an important role in the absorption of fats?
a) apolipoprotein B-48
b) apolipoprotein B-44
c) apolipoprotein B-30
d) apolipoprotein B- 34
Explanation: A shortened version of the protein, apolipoprotein B-48 is generated as a result of RNA editing. This protein is produced in the small intestines, responsible for the absorption of fats.
Sanfoundry Global Education & Learning Series – Cell Biology.
To practice all areas of Cell Biology, here is complete set of 1000+ Multiple Choice Questions and Answers.