This set of Biochemistry Multiple Choice Questions & Answers (MCQs) focuses on “Regulation of Transcription by Steroid Hormones”.
1. How do steroid hormones produce their effects in cells?
a) By activating key enzymes in metabolic pathway
b) By binding to intracellular receptors and promoting transcription of specific genes
c) By promoting degradation of specific m-RNAs
d) By activating translation of certain m-RNAs
Explanation: Steroid hormones produce their effects in cells by binding to intracellular receptors and promoting transcription of specific genes.
2. An example of positive regulator
b) Lac 1 gene
c) Trp operon
d) Met operon
Explanation: Lac 1 gene, Trp operon and Met operon are negative regulators.
3. An example of negative regulator
b) Lac 1 gene
c) Nuclear receptors
d) Phosphorylated STAT proteins
Explanation: CAP, Nuclear receptors and Phosphorylated STAT proteins are positive regulators.
4. Steroid regulatory proteins mediate the act by binding at
a) Zinc finger motif
b) Leucine zipper motif
c) Helix turn helix motif
d) Histone helix motif
Explanation: Steroid regulatory proteins mediate the act by binding at zinc finger motif.
5. Which out of the following statements is true about gene regulation in bacteria?
a) Repressor protein blocks transcription by binding to operator sequence
b) Activator proteins bind near promoters and increase the efficiency of transcription
c) Enhancers commonly regulate transcription
d) Genes with related functions are often grouped together and have a single start codon
Explanation: A repressor binds at operator element and regulates transcription negatively.
6. Steroid hormones receptor binds to
a) Hormone response elements in m-RNA
b) Hormone response elements in DNA
c) Hormone response elements in proteins
d) Ribosomes to stimulate translation
e) Cell membrane thereby increases permeability
Explanation: Hormone response elements are short sequence of DNA where steroid hormone receptors bind.
7. Mode of action of steroid hormones involve
a) Stimulation of DNA replication
b) Stimulation of m-RNA transcription
c) Inhibition of protein synthesis
d) Secondary messenger
Explanation: Steroid hormones involve in the stimulation of m-RNA transcription, affecting the gene expression.
8. The drug antagonist of estrogen is
Explanation: Tanoxifen is an antagonist of estrogen.
9. The drug used to terminate early pregnancies is
Explanation: Metformin, Glucophage and victoza are the drugs to cure diabetes.
10. Plasma membrane protein predicted to have seen 7 transmembrane helices segment binds
b) Thyroid stimulating hormone
d) Follicle stimulating hormone
Explanation: Progesterone hormone is a steroid hormone, can diffuse through cell membranes.
Sanfoundry Global Education & Learning Series – Biochemistry.
To practice all areas of Biochemistry, here is complete set of 1000+ Multiple Choice Questions and Answers.