CBSE Questions for Class 12 Medical Biology Strategies For Enhancement In Food Production Quiz 9 - MCQExams.com

Gonadotropin releasing hormone is a decapeptide that plays a vital role in regulating the reproductive processes. Release of this hormone from hypothalamus occurs in a pulsatile fashion and it is regulated by various internal and external signals. GnRH has its primary effects at the pituitary gonadotrope and stimulates the the gonadotropins luteinizing hormone (LH) and follicle-stimulating hormone (FSH).

A. Cauliflower

Pusa shubhra is a variety of cauliflower. It belongs to the third maturity group.  Curds are compact, slightly conical, creamish white in colour, non-ricey and non-leafy. It is suitable for the rainy season. Curds do not fade even under delayed harvesting and storage.

$$\textbf{Correct answer: A}$$ 

$$\textbf{Option (A):}$$ 

$$\bullet$$ In 1902, Professor Gottlieb Haberlandt first pointed out the possibilities of culturing isolated plant tissues. 

$$\bullet$$ He was the first person to consider culturing cells aseptically in a nutrient solution. 

$$\bullet$$ He is considered the father of plant tissue culture. 

$$\textbf{Option (B):}$$ 

$$\bullet$$ The experiment on plant tissue performed by Steward shows that in plants even mature cells can divide and differentiate again to produce a new plant. 

$$\bullet$$ This experiment defines the character of totipotency in the plant cell. 

$$\textbf{Option (C):}$$ 

$$\bullet$$ White's medium is one of the widely used medium in which the plants are grown specifically for root culture. 

$$\bullet$$ It has a low salt concentration with a higher concentration of magnesium sulphate. 

$$\bullet$$ This can also be used for the purpose of shoot culture and callus culture. 

$$\textbf{Option (D):}$$ 

$$\bullet$$ Murashige and Skoog medium is a plant growth medium in the laboratory which is used for the cultivation of plant cell culture. 

$$\bullet$$ MS media is a sucrose-containing medium where the plants grow. This media is widely used for the purpose of plant tissue culture even today. 

Hence, the correct answer is option (A).

Interspecific hybridization is the type of crossbreeding in which the hybridization takes place between the organisms of distinct species.

• Callus is defined as a group of cells derived from competent source tissue that is cultured under in vitro conditions to form an undifferentiated mass of cells.  
• Totipotency denotes the ability of a cell to generate an entire organism. For instance, if separated, each blastomere from a mouse 2-cell embryo is capable of developing into a complete organism. 
• An explant is a  cell, organ, or piece of tissue which has been transferred from animals or plants to a nutrient medium. 
• Embryoid bodies are aggregates of pluripotent cells that are induced to differentiate by a combination of a change in culture medium (removal of factors that support pluripotency) and allowing the cells to interact in three-dimensional structures. 

• Colostrum is rich in antibodies especially IgA.
• Chikungunya is caused Chikungunya virus and not bacteria.
• In the fermentation process, beer is obtained from barley while wine is obtained from grapes.
• Tissue culture has proved useful in obtaining virus-free plants by using apical meristematic tissue.