Genetics And Plant Breeding - Study Mode

[#771] Which of the following is a cytokinin?
Correct Answer

(B) Zeatin

Explanation

Solution: Zeatin is a cytokinin among the given options. Cytokinins (CK) are a class of plant hormones that promote cell division, or cytokinesis, in plant roots and shoots. Zeatin is a cytokinin derived from adenine, which occurs in the form of a cis- and a trans-isomer and conjugates. Zeatin was discovered in immature corn kernels from the genus Zea. It promotes the growth of lateral buds and when sprayed on meristems stimulates cell division to produce bushier plants.

[#772] Osmotic pressure in a vacuolated plant cell is usually
Correct Answer

(A) Equal to TP

Explanation

Solution: Osmotic pressure in a vacuolated plant cell is usually equal to TP. Osmotic pressure is the main cause of support in many plants. When a plant cell is in a hypotonic environment, the osmotic entry of water raises the turgor pressure exerted against the cell wall until the pressure prevents more water from coming into the cell. Here, OP becomes equal to TP. Vacuolated plant cells behave like ideal osmometers and plasmolytic contraction of the protoplast is also a concerned.

[#773] Law of homologus series' is given by
Correct Answer

(D) Vavilov

Explanation

Solution: The Law of homologous series' is given by Vavilov . The law of homologous series was formulated by N. I. Vavilov in 1920. The Journal of Genetics published Vavilov's paper in 1922. This law established a parallel variability of homologous characters in taxonomically near species. The Law of homologous series states that a particular variation observed in a crop species is also expected to be available in its related species.

[#774] The term chromosome was given by
Correct Answer

(C) Waldayer

Explanation

Solution: The term chromosome was given by Waldayer . A chromosome is a long DNA molecule with part or all of the genetic material of an organism. Most eukaryotic chromosomes include packaging proteins called histones which, aided by chaperone proteins, bind to and condense the DNA molecule to maintain its integrity. W. Waldeyer coined the term "chromosome" in 1888.

[#775] DNA polymerase I was discovered by
Correct Answer

(C) Kornberg

Explanation

Solution: DNA polymerase I was discovered by Kornberg . Arthur Kornberg, a prolific researcher who described his career as a “love affair with enzymes,” discovered DNA polymerase, an enzyme critical to DNA replication. For his discovery, Kornberg shared the 1959 Nobel Prize in Physiology or Medicine with Severo Ochoa, who discovered RNA polymerase I. this enzyme is also referred to as Kornberg enzyme.