For the generation of transgenic plants in crop improvement, one important gene X was expressed in a crop plant. Out of 30 transgenic rice plants generated, 22 showed high levels of gene X expression. However, rest 8 lines displayed low levels of expression. One explanation of such observation may be:

• suppression effect of the transgenic

• knock-down effect of the gene X.

• gene silencing effect

• co-suppression effect of the transgene

22.

Stem cells are widely used for their regenerative property and capacity to differentiate into different lineages. A person with a damaged liver approaches a stem cell therapist. Which of the following therapeutic strategies would be the safest?

• procuring adult liver cells from a healthy donor and grafting them into the patient.

• transforming skin cells from the patient into iPS cells and using them for further differentiation and grafting in the liver.

• injecting embryonic stem cells into the damaged liver.

• injecting cord blood cells into the liver directly

A plot of soil contaminated with diesel oil was inoculated with oyster mushrooms. After 4 weeks, more than 95% of the polycyclic aromatic hydrocarbons had been reduced to non-toxic compounds. This process is called

• phytoremediation

• chemoremediation

• mycoremediation

• zooremediation

One aims to find out the role of a gene product in macrophages by using a transgenic mouse expressing the genes under a promoter. Which of the following is the most appropriate promoter?

• Actin promoter

• MHC Class II promoter

• Mac-1/ CD 11b promoter

• IL-2 promoter

Which of the following genes was engineered in the "Flavr Savr" transgenic tomato variety?

• 1-Amino cyclopropane-1-carboxylic acid synthase

• 1-Amino cyclopropane-1-carboxylic acid oxidase

• Expansin

• Polygalactouronase

For developing transgenic mice, embryonic stem cells are engineered to express the transgene. These cells are selected by

• novobiocin

• neomycin

• tetracycline

• penicillin

Microbial leaching involves the process of dissolution of metals from ore breaking rocks using micro-organisms. Which one of the following bacteria helps in leaching copper from its ore?

• Acidithiobacillus ferroxidans

• Pseudomonas putida

• Deinococcus radiodurans

• Rhodopseudomonos capsulate

In a study of sexual isolation in a species of salamander, scientists brought together males and females from different populations and from the same population. they observed the frequency of mating and calculated a sexual isolation index. One graph shows the relationship between mating frequency and genetic distance, and the other shows the relationship between sexual isolation index and geographic isolation.

Choose the appropriate terms for X₁, Y₁, X₂, and Y₂ in the figures above

• X₁= geographic distance; Y₁ = sexual isolation index; X₂ = gentic distance; Y₂ = mating frequency

• X₁= geographic distance; Y₁ = mating frequency; X₂ = gentic distance; Y₂ = sexual isolation index

• X₁= gentic distance; Y₁ = mating frequency; X₂ = sexual isolation index; Y₂ = geographic distance

• X₁= gentic distance; Y₁ = geographic distance; X₂ = sexual isolation index; Y₂ = mating distance

In an experiment that has continued for more than 50 years, corn has been propagated by breeding only from plants with the highest amount of oil in the seeds. The average oil content is now much greater than any of the plants in the original population.

The following hypotheses were proposed as explanations for this observation.

(A) Mutations occurred increased the oil content in seeds.

(B) Plants with high oil content were stimulated to produce offspring with more oil in their seeds.

(C) The breeding led to increased frequency of alleles at multiple loci, so that new combinations of genes for even higher oil content were formed.

Which of the following represents a combination of correct statements?

• (A) and (B) only

• (A) and (C) only

• (B) and (C) only

• (A), (B), and (C)

While attempting to create a disease model of poliomyelitis in mice, it was found that mice cannot be infected with the said virus. Since human beings are susceptible to this viral infection, which kind of transgenic mouse model that can be infected with polio virus? Select the right approach from below:

• A mouse expressing surface protein of polio virus.

• A mouse expressing the human receptor gene which makes cell surface protein for docking and internalization of poliovirus.

• A mouse expressing human MHC class II invariant chain.

• A mouse expressing human receptor gene which makes cell surface protein for docking and internalization of poliovirus along with a gene designed to express surface protein of this virus at puberty.