Genetics And Plant Breeding - Study Mode

[#596] Organism having one chromosome pair less to the normal somatic complement of the species is
Correct Answer

(B) Nullisomic

Explanation

Solution: An organism having one chromosome pair less than the normal somatic complement of the species is Nullisomic. Nullisomic is a genetic condition involving the lack of both the normal chromosomal pairs for a species (2n-2). Humans with this condition will not survive. Nullisomy is caused by non-disjunction, during meiosis that causes two of the gametes to have no chromosomal material, leaving the other two gametes to have double the amount of chromosomal material.

[#597] Autopolyploidy is known as
Correct Answer

(B) Simple polyploidy

Explanation

Solution: Autopolyploidy is known as Simple polyploidy. Polyploidy is a mutation in which offspring have a multiple of some ancestral set of chromosomes. Polyploidy can occur either within a species (autopolyploidy) or between different species. An individual or strain whose chromosome complement consists of more than two complete copies of the genome of a single ancestral species.

[#598] An exchange of genetic material between homologous chromosomes is called
Correct Answer

(C) Crossing over

Explanation

Solution: An exchange of genetic material between homologous chromosomes is called Crossing over. crossing over is the exchange of genetic material during sexual reproduction between two homologous chromosome's non-sister chromatids that results in recombinant chromosomes. It is one of the final phases of genetic recombination, which occurs in the pachytene stage of prophase I of meiosis during a process called synapsis. The linked frequency of crossing over between two gene loci (markers) is the crossing-over value.

[#599] Match the following columns: Column I Column II a. Plasma membrane 1. Water potential b. Cellulose cell wall 2. Solute potential c. DPD 3. Permeable d. Osmotic pressure 4. Semipermeable
Correct Answer

(B) a-4, b-3, c-1, d-2

Explanation

Solution: a. Plasma membrane is semi-permeable. It is a type of biological or synthetic, the polymeric membrane that will allow certain molecules or ions to pass through it by osmosis. b. Cellulose cell wall is permeable. The cell wall of most plant cells is freely permeable to small molecules including small proteins, with size exclusion estimated to be 30 - 60 kDa. c. DPD and water potential is closely linked. The water potential has the same magnitude as DPD (Diffusion pressure deficit) but with a negative sign. d. Osmotic pressure and solute potential. Osmotic pressure is directly proportional to the solute potential. If the solute concentration of a solution increases, the potential for the water in that solution to undergo osmosis decreases.

[#600] "The ability of a gene to express itself in an individual that carries it" is defined as
Correct Answer

(B) Penetrance

Explanation

Solution: "The ability of a gene to express itself in an individual that carries it" is defined as Penetrance. The ability of a gene to express itself in an individual that carries it is called penetrance. Penetrance is the percentage of animals of a specific genotype who express the phenotype associated with that underlying genotype.