Continued inbreeding and especially close inbreeding reduces fertility and productivity in animals. This happens due to
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Inbreeding depression
Option (2) Inbreeding depression — Correct. Of the options, only inbreeding depression is the name NCERT gives to this fall in fertility and productivity. It is overcome by mating with unrelated superior animals of the same breed.
Note: This question is from Chapter 9, Strategies for Enhancement in Food Production, of the pre-rationalised NCERT book. This chapter is not in the present NCERT book (2026-27). The extract below is from the pre-rationalised edition.
NCERT Extract (Pre-rationalised edition, Chapter 9, Strategies for Enhancement in Food Production):
Animal Breeding – “… Try to recollect the homozygous purelines developed by Mendel as discussed in Chapter 5. A similar strategy is used for developing purelines in cattle as was used in case of peas. Inbreeding increases homozygosity. Thus inbreeding is necessary if we want to evolve a pureline in any animal. Inbreeding exposes harmful recessive genes that are eliminated by selection. It also helps in accumulation of superior genes and elimination of less desirable genes. Therefore, this approach, where there is selection at each step, increases the productivity of inbred population. However, continued inbreeding, especially close inbreeding, usually reduces fertility and even productivity. This is called inbreeding depression.”