Biology Test 316

Correct Answer :- b

Explanation : In mammals, including humans, insulin is synthesised as prohormone which needs to be processed before it becomes a fully mature and functional hormone. It contains an extra stretch called the C peptide which is removed during maturation into insulin. Therefore, post translational modification is not possible in bacterial cell.

Electrophoresis is a technique used to separate charged molecules, such as DNA, RNA, and proteins, based on their size and charge. Molecules are moved through a gel matrix under the influence of an electric field, allowing their separation.

Agrobacterium tumefaciens is a bacterium that naturally transfers part of its DNA (T-DNA) into plant cells, causing crown gall disease. Scientists use this mechanism as a vector to transfer foreign genes into plant cells, making it a tool for creating genetically modified plants.

PCR is a technique used to amplify DNA, involving denaturation, annealing, and extension steps, and can generate millions of copies of a specific DNA segment. However, cutting DNA into fragments is not a feature of PCR; this is performed by restriction enzymes.

The primary advantage of using GMOs in agriculture is that they can lead to increased yields and reduced pesticide use. Genetically modified crops can be engineered for pest resistance, herbicide tolerance, and improved nutritional content, among other traits, which can contribute to more sustainable agricultural practices.

The assertion is true as the F1 generation from a cross between two pure-breeding parents for two traits will indeed show only the dominant phenotype for each trait. The reason correctly explains this observation because, in a heterozygous condition, the dominant allele will mask the presence of the recessive allele, which is Mendel's law of dominance.

The assertion is correct as the presence of the Y chromosome in humans indeed determines the male sex. The reason accurately explains this because the SRY gene, located on the Y chromosome, triggers the development of male physical characteristics, making it the correct explanation for the assertion.

The assertion is true because blood type AB is an example of co-dominance where both alleles (A and B) express themselves fully in the phenotype. The reason correctly explains this phenomenon, as individuals with blood type AB indeed produce both A and B antigens on their red blood cells, making it the correct explanation for the assertion.