15 extra multiple-choice questions for Breeding and Biotechnology (10th Standard Science, Samacheer Kalvi), beyond the ones printed in the textbook — each with the correct option highlighted and a clear, worked explanation. Free to read in English and Tamil.
Q1
The development of improved crop varieties with higher yield, better quality and shorter duration is called
- A. Crop improvementCorrect
- B. Crop rotation
- C. Crop protection
- D. Crop storage
Explanation. Crop improvement is the development of improved crop varieties possessing higher yield, better quality, resistance to diseases and shorter duration.
Q2
Breeding between animals of the same breed is called
- A. Outbreeding
- B. InbreedingCorrect
- C. Cross breeding
- D. Hybridisation
Explanation. When breeding takes place between animals of the same breed it is called inbreeding, whereas a cross between different breeds is called outbreeding.
Q3
The cross between two different breeds of animals is known as
- A. Inbreeding
- B. OutbreedingCorrect
- C. Selection
- D. Cloning
Explanation. Outbreeding is the cross between different breeds. It is the opposite of inbreeding, which keeps the mating within a single breed.
Q4
The superiority of a hybrid obtained by cross breeding is called
- A. Inbreeding depression
- B. HeterosisCorrect
- C. Mutation
- D. Selection
Explanation. The superiority of the hybrid obtained by cross breeding is called heterosis or hybrid vigour, and it is the main reason cross breeding is practised.
Q5
The manipulation and transfer of genes from one organism to another is called
- A. Genetic engineeringCorrect
- B. Tissue culture
- C. Mass selection
- D. Vaccination
Explanation. Genetic engineering is the manipulation and transfer of genes from one organism to another, and it underlies recombinant DNA technology.
Q6
Undifferentiated or unspecialised masses of cells that can be used in therapy are called
- A. Nerve cells
- B. Stem cellsCorrect
- C. Blood cells
- D. Muscle cells
Explanation. Stem cells are undifferentiated or unspecialised masses of cells that can be used for the treatment known as stem cell therapy.
Q7
Golden rice was developed to correct the deficiency of
- A. Vitamin ACorrect
- B. Vitamin C
- C. Iron
- D. Iodine
Explanation. Golden rice carries a beta carotene gene so that the grain produces the precursor of vitamin A, which is intended to relieve vitamin A deficiency.
Q8
The Bt gene used to make insect resistant crops is obtained from
- A. a virus
- B. a bacteriumCorrect
- C. a fungus
- D. an alga
Explanation. The Bt gene comes from the bacterium Bacillus thuringiensis. It makes a protein toxic to insects, so crops carrying it resist insect attack.
Q9
Variable number tandem repeats used in DNA fingerprinting are also known as
- A. Vector DNA
- B. Satellite DNACorrect
- C. Recombinant DNA
- D. Single stranded DNA
Explanation. The tandem repeat sequences that serve as the basis of DNA fingerprinting are known as satellite DNA, and their number differs from one individual to another.
Q10
DNA fingerprinting is widely used in forensic work mainly for
- A. identifying the culprit in a crimeCorrect
- B. increasing crop yield
- C. producing vaccines
- D. cutting DNA strands
Explanation. The technique is widely used in forensic applications such as crime investigation, where it helps identify the culprit by comparing DNA patterns.
Q11
The DNA molecule that carries a desired gene into a host cell is called a
- A. VectorCorrect
- B. Enzyme
- C. Hormone
- D. Toxin
Explanation. A vector is the carrier DNA into which the desired gene is inserted. The combination of vector DNA and desired DNA is recombinant DNA.
Q12
Approximately how many base pairs does the human genome contain?
- A. 3 million
- B. 3 billionCorrect
- C. 30 thousand
- D. 300
Explanation. The chapter states that the human genome has three billion base pairs, which is why comparing whole genomes directly would be impractical.
Q13
Selection of the best plants from a mixed population, keeping their seed for the next sowing, describes
- A. Mass selectionCorrect
- B. Hybridisation
- C. Mutation breeding
- D. Genetic engineering
Explanation. Mass selection works on a mixed population, retaining seed from the better plants. It is the simplest method and needs no technical training.
Q14
Crops carrying a gene introduced from another organism are called
- A. Hybrid crops
- B. Transgenic cropsCorrect
- C. Pureline crops
- D. Clonal crops
Explanation. An organism carrying a foreign gene is transgenic, and such crops are also described as genetically modified. Hybrids arise from crossing, not gene transfer.
Q15
Treatment of a disorder by introducing undifferentiated cells into the body is called
- A. Gene therapy
- B. Stem cell therapyCorrect
- C. Chemotherapy
- D. Physiotherapy
Explanation. Stem cells are undifferentiated cells, and their use in treating disorders is known as stem cell therapy.
About these Breeding and Biotechnology questions
These are the Additional multiple-choice questions for Breeding and Biotechnology from the Tamil Nadu State Board (Samacheer Kalvi) 10th Standard Science syllabus. Each question shows the correct option and an original, step-by-step explanation so you understand the method, not just the answer. Use the answer key above to jump to any question, then take the practice test to check yourself under exam-like conditions.
Frequently asked questions
How many MCQs are there in Breeding and Biotechnology?
This chapter has 15 book-back multiple-choice questions, each with the correct answer and a step-by-step explanation.
Are these 10th Standard Science MCQs free to practise online?
Yes. Every question, answer and explanation here is free, and you can also take them as a timed practice test.
Where can I find the Breeding and Biotechnology book-back answers?
The correct option for each question is highlighted on this page with a worked explanation, plus a quick answer-key summary at the top.
