Tag: biology

Quizzes (1160) Questions (12174)

Questions Related to biology

Multiple choice biology improvement in food resources crop variety improvement improvement if crop varieties improvement in crop variety

Method of preserving favourable variants and elimination of undesirable plants is termed as________

  1. Selection

  2. Hybrid

  3. Hybridization

  4. Somatic hybrids
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

  • The selection is the oldest method of plant breeding in which the two plants are selected on the basis of the superior characters. This method helps in the elimination of undesirable characters. The two plants are selected in order to preserve the favorable traits. This method involves the preservation of the plants which have superior characters. 
Thus, the correct answer is option A. 

Multiple choice biology improvement in food resources crop variety improvement improvement if crop varieties improvement in crop variety

Which of these is not a major group of activities for improving crop yield?

  1. Crop protection management

  2. Crop production management

  3. Crop variety improvement

  4. Crop transport management
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Many different management programs are undertaken in order to improve the yield of the crop plants. The crop protection, production, and variety improvement are the management programs which help to enhance the yield of the crop. The transport management is not a part of crop yield increase. 

Thus, the correct answer is option D. 

Multiple choice biology improvement in food resources crop variety improvement improvement if crop varieties improvement in crop variety

The crosses are made between two different species of the same genus is known as

  1. Interspecific hybridization

  2. Intraspecific hybridization

  3. Intra-varietal hybridization

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The crossing between two plants of different species to produce a new variety is called hybridization. Genetically modified crops can be produced by insertion of genes with desired traits by the process of hybridization.Crossing may be between two different varieties (intra-varietal cross breeding), between two different species of same genus (interspecific crossbreeding) and between different genera (intergeneric crossbreeding). The crossing between two species of same genus is known as interspecific cross breeding. 
Thus, the correct answer is option A. 
Multiple choice biology improvement in food resources crop variety improvement improvement if crop varieties improvement in crop variety

Choose the correct statement.

A) Hybridization is used to exploit and utilise the hybrid varieties.
B) Hybridization creates variation.

C) Hybridization leads to recombination of characters.

  1. Only A

  2. Only B

  3. Only C

  4. A, B and C
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The crossing between genetically different plants to produce a new variety is called as hybridization. Genetically modified crops can be produced by insertion of genes with desired traits by the process of hybridization. The parents are allowed to perform hybridization and the offspring is known as the hybrid. The hybrid is allowed to self-pollinate in order to maintain a pure breed of the hybrid. The hybrid varieties are used for better crop production. There is the mating of two different plant species which results in genetic variation. There is the recombination of the characters of both the parent plants. 

Thus, the correct answer is option D. 

Multiple choice biology improvement in food resources crop variety improvement improvement if crop varieties improvement in crop variety

The trait which is accounted for hybridization is

  1. Resistance to diseases

  2. Productivity

  3. Tolerance to climatic condition

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The crossing between two plants of different species to produce a new variety is called hybridization. The new plant which is produced is known as the hybrid which possesses superior characters of both the parent plants. The traits which are considered for hybridization are resistance to pests, insects and diseases, an increase in the productivity and high yielding, tolerance to adverse conditions, etc. The hybrid is called as hybrid vigor which has better characteristics when compared to the parental types. 

Thus, the correct answer is option D. 

Multiple choice biology improvement in food resources crop variety improvement improvement if crop varieties improvement in crop variety

Which of the following practices can be related to hybridisation?

  1. Segregation

  2. Recombination

  3. Variation

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Hybrid plants can be developed by the breeding of the plants of different species. This is known as the process of hybridization. The parents are genetically different plants. There is segregation of the characters which results in the formation of offspring which have superior characters when compared to the parents. There is recombination which introduces certain new genes in the offspring. Due to genetic recombination, variations are produced. The offsprings are genetically different from the individual parents. 

Thus, the correct answer is option D. 

Multiple choice biology improvement in food resources crop variety improvement improvement if crop varieties improvement in crop variety

.......... is a sterile hybrid which spreads by rhizome division

  1. Iris albicans

  2. Evening primrose

  3. Tangelo

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Hybrid plants can be developed by the breeding of the plants of different species. The parents are genetically different plants. Iris albicans is the sterile hybrid which is developed by breeding of two different species. This is known as interspecific hybridization. This is a sterile plant which spreads by rhizome division.

Thus, the correct answer is option A. 

Multiple choice biology improvement in food resources crop variety improvement improvement if crop varieties improvement in crop variety

Which of the following is not applicable to biological species concept?

  1. Hybridisation

  2. Reproductive isolation

  3. Natural selection

  4. Gene pool
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Answer is option A i.e. "Hybridisation"
The biological species concept defines a species as members of populations that interbreed in nature. According to this concept, organisms belong to the same species if they can interbreed to produce viable, fertile offspring. Reproductive isolation, natural selection and gene pool are applicable to one species.
Hybridisation, on contrary, occurs due to process of combining two different species of organisms to create a hybrid.
Hence, "hybridisation" is not applicable to biological species concept.

Multiple choice biology improvement in food resources crop variety improvement improvement if crop varieties improvement in crop variety

Total number of meiotic division required for forming $100$ zygotes/ $100$ grains of wheat is?

  1. $100$
  2. $75$
  3. $125$
  4. $50$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In angiosperms, one meiotic division produces 4 microspores, but only one functional megaspore is formed from one megaspore mother cell. For 100 grains, 100 meiotic divisions are needed for the male side (pollen) and 100 for the female side (ovule), totaling 200. However, if the question implies the standard formula (n + n/4), it is 125.