NCERT Solutions for Class 10th Science
Chapter 8. How do Organisms Reproduce
- Full Form of DNA is Deoxyribo Nucleic Acid.
- In fission, many bacteria and protozoa simply divide into two or more daughter cells.
- Roots, stems and leaves of some plants develop into new plants through vegetative propagation.
- Simple animals like Hydra and Planaria can be cut into any number of pieces and each piece grows into a complete organism. This is known as regeneration.
- New plants are grown by removing tissue or separating cells from
the growing tip of a plant is called Tissue culture.
- Unisexual flowers may be papaya and watermelon.
- The transfer of pollen grains from the stamen to the stigma in the same flower is called self pollination.
- The transfer of pollen grains from the stamen to the stigma from one flower to another flower is called cross pollination.
- The seed contains the future plant or embryo which develops into a seedling under appropriate conditions. This process is known as germination.
- Sperm formation requires a lower temperature than the normal body
- The two oviducts unite into an elastic bag-like structure known as the
- Male sex hormone is testosterone.
- Female sex hormone is estrogen.
- The developing embryo will also generate waste substances which can be removed by transferring them into the mother’s blood
through the placenta.
- The lining slowly breaks and comes out through the vagina as blood and mucous. This cycle takes place roughly every month and is known as menstruation.
- The bacterial infections such as gonorrhoea and syphilis, and viral infections such as warts and HIV-AIDS.
- Contraceptive devices such as the loop or the copper-T are placed in the uterus to prevent pregnancy.
- The male reproductive system in human beings consists of testes which produce sperms, vas deferens, seminal vesicles, prostate gland, urethra and penis.
- The female reproductive system in human beings consists of ovaries, fallopian tubes, uterus and vagina.