How do Organisms Reproduce Test - 18

Uterus prepares every month to receive a fertilized egg. The lining of the uterus becomes thick, vascular and spongy. This occurs in order to provide nourishment to the future embryo. When the egg is not fertilized, it leads to the shedding of the lining of the uterus and egg in the process called menstruation. These are expelled out through the vagina in the form of blood and mucus.
Therefore, the correct answer is option C.

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.

At the age of puberty due to the action of testosterone enlargement of the larynx is seen in boys. Vocal cords are situated in the larynx. These vocal cords increase in length and become thick due to the action of testosterone. This change results in the cracking of voice in boys. In girls, vocal cord length increases but larynx enlargement is not visible noticeably. 

Puberty can be defined as the process where the child undergoes several physical changes due to fully developed sexual organs. On average, girls begin puberty at ages 10-12, boys at ages 11-13. Girls usually complete puberty by 15-16 while boys usually complete puberty by ages 16-17.
So, the correct answer is option A.

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 where the child undergoes several physical changes due to fully developed sexual organs. Two of the most significant differences between puberty in girls and puberty in boys are the age at which it begins, and the major sex hormones involved, the testosterone and the estrogens.
Girls typically begin the process of puberty at age 10 or 11 and boys at ages 11 or 12.
So, the correct answer is option A.

An amoeba is a type of single-celled organism which has the ability to alter its shape by extending and retracting its pseudopodia. So, blank 1 contains the word 'single'.
The mode of reproduction in amoeba is asexual reproduction. So, blank 2 contains the word 'asexual'.
As genetic material or nucleus is first replicated and divided, and then the cell is divided, blank 3 and 4 contains the word 'nucleus' and 'cytoplasm' respectively. While the last blank contains the word 'binary', as amoeba reproduces by binary fission.
Thus, the correct answer is option (B), 'Single, asexual, nucleus, body, binary.'.

• 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.
  

The endometrium or the innermost lining of the uterus thickens each time an egg is released. The thickening is due to the increase in the number of blood vessels in order to provide a surplus supply of nutrients and oxygen to the embryo if the released egg gets fertilized.