CBSE Questions for Class 12 Medical Biology Strategies For Enhancement In Food Production Quiz 1 - MCQExams.com

• Colostrum is a milky fluid that comes from the breasts of mammals the first few days after giving birth before true milk comes and is rich in proteins, carbohydrates, fats, vitamins, minerals, and antibodies (not antigens). So, statement A is incorrect.
• Chikungunya is caused by the chikungunya virus (not bacteria). So, statement B is incorrect.
• Tissue culture has proved useful in obtaining virus-free plants. This is correct.

• Interspecific hybridization refers to a cross between two individuals of two different species or different genera to bring their characters together in the hybrid progeny. Mule is produced by interspecific hybridization.
• A cross between superior males and females of different breeds refers to cross-breeding while that between animals within the same breed without having common ancestors is called outcrossing. 

• Biofortification is a process of increasing the density of vitamins and minerals in a crop through plant breeding, transgenic techniques, or agronomic practices. Biofortified crop is a good source of higher protein, minerals and healthier fats and when consumed regularly, will generate measurable improvements in human health and nutrition.
• Azolla is a floating pteridophyte, which contains as endosymbiont the nitrogen-fixing cyanobacterium Anabaena azollae. Thus it acts as a biofertilizer by functioning as a nitrogen source to plants.
• So, the correct answer is 'Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion'

• Apiculture or beekeeping is the method of management and study of the honey bee. 
• Apiculture is a way by which honey bees are reared and managed for the production of honey, bee wax, and propolis.  
• Hence, option A is correct.

• Sheep is an animal that has a rich layer of wool over it. It is used for economic purposes. Many blankets, sweaters, jackets, etc are obtained from sheep wool.

A. Catla is a major carp fish and is economically important.
B. Labestes is a larvivorous fish and feeds on other fishes.
C. Gambusia is known as mosquito fish as it feeds on the larva of the mosquitoes.
D. Aplocheilus is known as Killifish and it is an aquarium fish.
Hence, an indigenous fish used in biological control is Labestes.
So, the correct answer is 'Labestes'.

• Poultry farming is undertaken to raise domestic fowl for egg production and chicken meat.
• Chickens that are reared especially for meat are called broilers.
  
• Broilers have tender meat with soft, pliable, smooth textured skin and flexible breast bone cartilage.
  

• The practice of cultivating more then one species of fish in a single pond is known as polyculture or composite culture. 
• Production of fish in ponds may be increased by raising a combination of species having different food habits. 

• The cells are from a variety of microorganisms such as bacteria, yeasts, filamentous fungi, and algae that are used as food or feed are called single-cell proteins (SCP). e.g. Spirulina (algae) and Chlorella.
  

Plants can be disease resistant by breeding with a plant which naturally have resistance gene. Generally, wild varieties of plants have resistance gene for disease so breed important crop with their wild varieties to get disease resistant plants.

$$\textbf{Correct answer: A}$$ 

$$\textbf{Option (A):}$$ 

$$\bullet$$ A callus is an undifferentiated mass of tissue. This tissue is mainly found in plant tissue culture, which later differentiates to form new plants. 

$$\bullet$$ It shows similarity in character to the tumorigenic growth in animals. 

$$\bullet$$ The growth of callus depends on the activity of plant growth modulators like the plant hormones auxin and cytokinin.

$$\textbf{Option (B):}$$ 

$$\bullet$$ Root formation in culture medium occurs only after differentiation of the tissues. 

$$\textbf{Option (C):}$$ 

$$\bullet$$ Plant hormones are responsible for specific properties in the plants including growth and differentiation into specific plant parts. 

$$\textbf{Option (D):}$$ 

$$\bullet$$ Plant by-products are produced only after the plant is fully grown producing all the metabolic end-products.

$$\bullet$$ Some of these end products are useful for animals and humans.

Hence, the correct answer is option (A).

• The cultivation of fishes, oysters, shrimps, and crabs comes under aquaculture. 
• Sericulture is the culture and rearing of silkworms.
• Silviculture is the practice of controlling the growth, composition/structure, and quality of forests to meet values and needs, specifically timber production.
• Pisciculture is the culture of only fishes for commercial production.