All Free Biology MCQs with Answers

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19844 questions · page 535 of 1985

5341. Which of the following products is prepared by recombinant DNA technology?

Moderate
  • A. Hepatitis B vaccine
  • B. Growth hormone
  • C. Insulin
  • D. All of the above

Explanation: Biotechnology products produced by bacteria, such as insulin, human growth hormone, tissue plasminogen activator, hemophilia factor Vm, and hepatitis B vaccine are now on the market.

Correct answer: All of the above

5342. The degradation of pollutants with the help of recombinant bacteria is called:

Moderate
  • A. Biofilters
  • B. Biodegradation
  • C. Biosorption
  • D. None of the above

Explanation: Biodegradation is the process by which microorganisms break down organic matter. Depending on the material, this can take days, weeks or even centuries. Products that biodegrade quickly are preferable to those that don't; their harmful contents can be broken down in a shorter period of time.

Correct answer: Biodegradation

5343. The bacteria used in industries for control of pollution are:

Moderate
  • A. Biosorption
  • B. Biodegradation
  • C. Biofilters
  • D. None of the above

Explanation: Biofiltration is a pollution control technique using a bioreactor containing living material to capture and biologically degrade pollutants. Common uses include processing waste water, capturing harmful chemicals or silt from surface runoff, and microbiotic oxidation of contaminants in air.

Correct answer: Biofilters

5344. The genes which cause self-destruction of bacteria are:

Moderate
  • A. Phage genes
  • B. Suicide genes
  • C. Recombinant genes
  • D. Plasmid genes

Explanation: In the field of genetics, a suicide gene is a gene that will cause a cell to kill itself through the process of apoptosis (programmed cell death). Activation of a suicide gene can cause death through a variety of pathways, but one important cellular "switch" to induce apoptosis is the p53 protein.

Correct answer: Suicide genes

5345. The bacteria are used in mining industry for:

Moderate
  • A. Biosorption
  • B. Biodegradation
  • C. Biofilters
  • D. Bioleaching

Explanation: Bioleaching (or biomining) is a process in mining and biohydrometallurgy (natural processes of interactions between microbes and minerals) that extracts valuable metals from a low-grade ore with the help of microorganisms such as bacteria or archaea.

Correct answer: Bioleaching

5346. The plant cells whose cell wall is removed are:

Moderate
  • A. Naked cells
  • B. Callous
  • C. Protoplast
  • D. All of the above

Explanation: Protoplasts are isolated cells produced by removing the surrounding cell wall either by mechanical means or by the use of cell wall degrading enzymes. Removal of the cell wall leaves the protoplast surrounded by the plasmalemma membrane.

Correct answer: Protoplast

5347. In which of the following plant pest and herb resistant genes are not used?

Moderate
  • A. Cotton
  • B. Corn
  • C. Yeast
  • D. Potato

Explanation: Some corn and cotton plants are both pest and herbicide resistant.

Correct answer: Yeast

5348. The acreage of transgenic plants in 1999 was:

Moderate
  • A. 50 million
  • B. 70 million
  • C. 90 million
  • D. 100 million

Explanation: In 1999 these transgenic crops were planted on more than 70 million acres worldwide and the acreage is expected to triple in about five years.

Correct answer: 70 million

5349. Green revolution was launched in:

Moderate
  • A. 1960
  • B. 1970
  • C. 1990
  • D. 2000

Explanation: World grain harvests have continued to rise since the 1960s when special high-yield hybrid plants were developed during the so called green revolution.

Correct answer: 1960

5350. Scientists are working on which of following to increase yield:

Moderate
  • A. Stomata
  • B. RuBP carboxylase
  • C. C4 cycle
  • D. All of the above

Explanation: All of these if improved helps in increasing the yield of crops.

Correct answer: All of the above