CBSE Questions for Class 10 Biology How Do Organisms Reproduce Quiz 2 - MCQExams.com

• Contraception is the method to prevent unwanted pregnancy. 
• Different methods of contraception include caps, combined pill, condoms (female), condoms (male), contraceptive implant, contraceptive injection, contraceptive patch, diaphragms, intrauterine devices (IUDs), natural family planning, progestogen-only pill, vaginal ring.

• The consistency of DNA copying during reproduction is important for the maintenance of body design features that allow the organism to use that particular niche.
• Every organism faces a lot of competition for survival. Barring a very few, most of the organisms end up being food for some other organism. 
• Competition and predation result in a drastic reduction in the population size of a species. But reproduction ensures that the population of a species is maintained at an optimum level. 
  
• Reproduction is therefore linked to the stability of populations of species. 

Many organisms like Hydra reproduce by the process of regeneration, where fragments of an organism regrow into a complete organism by undergoing the process of development. It also involves passing on the genes from parent to offspring generation after generation for continuity of species. Thus, the importance of reproduction is both regeneration and passing on of genes.

Hence, the correct option is D.

A) Correct Option – B

B) Explanation for correct option -

• The zygote or normally the fertilized egg is actually the diploid cell that is formed from the fusion of a female gamete (the egg) with a male gamete (the sperm). 
• The zygote finally undergoes cleavage to form the embryo which grows into a young one. 

A) Correct Option – B

B)  Explanation for correct option -

• The male gamete is generally formed by the process of spermatogenesis in human males. 
• The female gamete is generally formed by the process of oogenesis in human females. This process of formation of both the male and female gametes is called gametogenesis.
• Syngamy is a process that is defined by the fusion of the male gametes (sperms) with the female gametes (eggs) that results in the formation of a diploid zygote in the end.
• Embryogenesis takes place almost eight weeks after fertilization.

• Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. Puberty thus marks the beginning of the reproductive period. 
• Adolescence is the period of transition during which a child grows and matures into an adult. An adolescent is any person between 10 and 19 years of age.
• Menopause is the time that marks the end of the menstrual cycles.
  

• Binary fission and budding both are the modes of asexual reproduction. But in binary fission, the parent cell splits into two daughter cells and loses its identity.
• Whereas in budding, the parent cell first produces an outgrowth or bud which gets detached after maturity and survives as an individual. The parent identity is thus retained. 
• In binary fission, the cytoplasm divides evenly whereas in budding cytoplasm divides unevenly.
  Hence, the correct answer is B.

• Spirogyra is a genus of filamentous green algae which reproduce by fragmentation. The body of Spirogyra on maturing simply breaks up into smaller pieces or fragments. These pieces or fragments then grow into new individuals.
• Rhodella is reproduced through binary fission.
• Caulerpa is reproduced through zoospores, and also vegetative and sexual reproduction is present.