Tag: biology

After ovulation only matured eggs can be fertilized in reproduction. After fertilization at blastocyst stage implantation occurs in uterine wall and development of embryo takes place. Thus, the correct answer is option D.

After fertilization, male and female gametes fuse to form a zygote. The zygote undergoes changes to form an embryo having two cells. Then there are successive divisions in embryo and formation of morula and blastula occurs. The embryo gives rise to a new individual. The embryo undergoes organogenesis and forms a new individual.

Sexual reproduction is the process wherein gametes both from male and female fuse together to give rise to a new progeny.
Steps involved in sexual reproduction :

• Male gametes are produced in male reproductive organ by the process called spermatogenesis in semeniferous tubules in gonads and female gametes are produced in female reproductive organ by the process called oogenesis in the ovaries. This process is called gametogenesis.
  

• The sperm (male gamete) enters the ovum (female gamete) by rupturing the cell wall of ovum and releases its chromosomal material in the ovum. This process is called fertilization. Wherein the egg is fertilized by a sperm.
  
• Fertilisation process brings together two sets of chromosome, one from female and one from male. Thereby forming a diploid cell called zygote. Hence called zygote formation.
  
• The newly formed zygote undergoes many cycles of cell division passing the stages from morula, blastula and giving rise to a multicellular structure called embryo through the process called embryogenesis.
  

Zygote or the fertilized egg is the diploid cell that is formed from the fusion of a female gamete (ovum) with a male gamete (sperm). Zygote is the universal diploid cell. The zygote undergoes cleavage to form the embryo. Thus, the correct answer is option B.

Fertilization that takes place inside the female body is called internal fertilization. In human fertilization takes place in the oviduct. During fertilization motile sperm moves towards egg and fuse to form the zygote. Thus, the correct answer is option D.

Fertilization is the process of fusion of human egg and sperm. Where sperm enters through vagina and encounters the ovum for fusion in fallopian tube During fertilization acrosome reaction takes palce between the zona pallucida membrane and enzyme in acrosome. Thus, the correct answer is option B.

• After a certain age, An individual becomes sexually and mentally mature. After that age an individual becomes adults.
•  According to the Indian Government marriage should be after maturity of individuals. Prohibition of Child Marriage Act states that a girl in India can't marry before the age of 18, and a boy before 21 yrs. 

The male gamete is formed by spermatogenesis. The female gamete is formed by oogenesis. This process of formation of male and female gametes is called gametogenesis. Syngamy is a process in sexual reproduction that is defined as the fusion of the male gamete i.e., sperm with the female gamete i.e., egg resulting in the formation of a diploid zygote. Embryogenesis takes place eight weeks after fertilization. Thus the correct answer is option B.

The opening of the vagina is covered partially by a membrane called hymen. This membrane is often torn during the first coitus (intercourse). However, it can also be broken by a sudden fall or jolt, insertion of a vaginal tampon, active participation in some sports like horseback riding, cycling, etc. Moreover, in some women, the hymen persists even after coitus. Hence, the presence or absence of hymen is not a reliable indicator of virginity or sexual experience.

The steps of fertilization in humans always involve the joining of an egg and sperm. In natural conception, the male sperm fertilizes the female egg inside the woman’s body. While many think fertilization occurs in the ovary, it actually takes place in the fallopian tube just outside the ovary. From there, the fertilized egg travels down the fallopian tube. If it successfully implants in the uterus, an embryo can begin to grow.