Practice Questions

TLS Online TPP Program

#Question id: 101

You have two bottles, each of which contains a white, crystalline substance. Your lab director tells you that one contains lactose and the other sucrose. Your job is to determine which bottle contains which sugar. Which procedure would you use?

#Biochemistry

Test both for solubility in water. Sucrose is very soluble; lactose is only minimally soluble.
Test for the ability to reduce Ag+. Only lactose will react.
Dissolve each in water and record the pH. Lactose is far more acidic than sucrose.
React each with bromine (Br2) water. Only sucrose will react.

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TLS Online TPP Program

#Question id: 39288

#Plant Biotechnology

Q. Assertion: Cybrids allow for the combination of mitochondria from one species with chloroplasts from a different species.

Reason: This combination can be used to overcome deleterious effects, such as chlorophyll deficiency, found in some alloplasmic lines.

TLS Online TPP Program

#Question id: 39289

#Plant Biotechnology

Q. Assertion:Brassica napus lines carrying Ogura (radish) cytoplasm are highly efficient for commercial growth in cold climates without any modifications.

Reason: The presence of radish chloroplasts in these lines causes chlorophyll deficiency under low temperatures.

TLS Online TPP Program

#Question id: 39290

#Plant Biotechnology

Q. Assertion: Protoplast fusion between CMS B. napus (with radish cytoplasm) and normal B. napus can produce healthy male sterile plants.

Reason: The resulting cybrids can retain the radish mitochondria (for CMS) while replacing the radish chloroplasts with B. napus chloroplasts.

TLS Online TPP Program

#Question id: 39291

#Plant Biotechnology

Q. Assertion: In plant breeding, cytoplasm transfer via somatic hybridization is significantly faster than conventional backcrossing.

Reason: Protoplast fusion can achieve in one year what typically takes 5–6 years through the backcrossing method.

TLS Online TPP Program

#Question id: 39292

#Plant Biotechnology

Q. Assertion: Symmetric hybrids allow for the transfer of genes between species that are sexually incompatible.

Reason: Somatic hybridization bypasses the requirements of pollination and fertilization, enabling fusion between even completely sterile lines like monoploids.

TLS Online TPP Program

#Question id: 39293

#Plant Biotechnology

Q. Assertion: Cybridization enables the creation of unique organelle combinations that cannot be produced through sexual reproduction.

Reason: Somatic fusion allows the mitochondria of one species to be combined with the chloroplasts of another, often resulting in recombinant organellar genomes.