Genetics And Plant Breeding - Study Mode

[#411] Gene control the production of enzyme was given by
Correct Answer

(A) E. L. Tatum

Explanation

Solution: Gene controls the production of enzymes given by E. L. Tatum. He shared half of the Nobel Prize in Physiology or Medicine in 1958 with George Beadle for showing that genes control individual steps in metabolism. Beadle and Tatum's key experiments involved exposing the bread mold Neurospora crassa to x-rays, causing mutations. In a series of experiments, they showed that these mutations caused changes in specific enzymes involved in metabolic pathways.

[#412] The number of bases in the single turn of the DNA helix is
Correct Answer

(C) 10

Explanation

Solution: The number of bases in the single turn of the DNA helix is 10. DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. DNA is a long polymer made from repeating units called nucleotides, each of which is usually symbolized by a single letter: either A, T, C, or G. DNA can be twisted like a rope in a process called DNA supercoiling. With DNA in its "relaxed" state, a strand usually circles the axis of the double helix once every 10 base pairs.

[#413] Male sterility promotes
Correct Answer

(B) Outbreeding

Explanation

Solution: Male sterility promotes Outbreeding. The presence of male sterility leads to heterozygosity in a species as it promotes outbreeding and reduces homozygosity due to the elimination of inbreeding. Male sterility results from the action of nuclear genes or cytoplasmic genes or both. Male sterility is caused due to pollen or anther abortion. Outbreeding refers to matings between individuals from different populations, subspecies, or species. Outbreeding can result in a decline in reproductive fitness known as outbreeding depression, but this is less common than inbreeding depression.

[#414] What is the frequency of getting AABBCC individuals from a mating of two AaBbCc individuals?
Correct Answer

(A) 1 / 64

Explanation

Solution: The frequency of getting AABBCC individuals from a mating of two AaBbCc individuals is 1 / 64 . The parents with genotype AaBbCc X AaBbCc gives 64 offsprings with different genotypes, but only 1 individual will have all dominant genes i.e. AABBCC. Genotype frequency in a population is the number of individuals with a given genotype divided by the total number of individuals in the population.

[#415] Centromere dividation occurs during which stage of Mitosis?
Correct Answer

(C) Anaphase

Explanation

Solution: Centromere division occurs during the Anaphase stage of Mitosis. It is the stage of mitosis after the process of metaphase when replicated chromosomes are split and the newly-copied chromosomes (daughter chromatids) are moved to opposite poles of the cell. The centromeres are split, and the sister chromatids are pulled toward the poles by kinetochore microtubules. They take on a V-shape or Y-shape as they are pulled to either pole.