- Reproduction : Process of giving birth to new organisms.
- Species : largest group of organisms in which two individuals can produce new organism.
- Variation : Improper DNA copying leads to variation in new organism, where organisms are similar to their parents but not identical.
- Asexual mode of reproduction : [Refer the video to understand in detail]
- Fission : Division of cell in two or more parts. Unicellular organism reproduce by fission.
- Binary fission : Organism split into two equal halves during cell division to form new organism. E.g. Amoeba.
- Multiple fission : Split into many daughter cells during cell division. E.g. Plasmodium.
- Reproductive organs in flower are stamen and carpel.
- [Image Reference : Link]
- Stamen : Male reproductive part produces pollen grain. Pollen grain bears male gamete.
- Carpel : Female reproductive part which contains stigma, style and ovary.
- Stigma : Sticky terminal part.
- Style : Middle elongated part.
- Ovary : Swollen bottom part containing ovules which contains germ cells/ egg cells.
- Unisexual : Posses only one type of sex organ. E.g. Flowers of Papaya, Watermelon.
- Bisexual : Posses both the sex organs. E.g. Flowers of Hibiscus, mustard.
|Asexual Reproduction||Sexual Reproduction|
|One parent needed in asexual reproduction.||Two parents needed in sexual reproduction|
|No formation and fusion of gametes||Involves formation and fusion of gametes|
|Reproduced organisms are genetically similar to parents.||Reproduced organism are genetically different from parents.|
|Is a Fast process||Is a Slow process|
|E.g Reproduction in Hydra, Bryophyllum, etc.||E.g. Reproduction in human being, animals, flowering plants etc.|
- Reproduction in Human beings:
- Common signs of maturity in both males and females: Faster body growth, thinner hairs on arms and legs, darkening of skin, pimple and oily skin, Increased Consciousness about body, attraction towards opposite sex.
- Signs of maturity in males: Voice begins to crack, thick hair growth on face, in armpits and at genital area. Penis starts to become enlarged. It occasionally become erect.
- Signs of maturity in females: Breast size begins to increase, menstruation starts at this stage.
- Male Reproductive System: [Refer the video to understand in detail] Male reproductive system consists of testes, vas deferens, penis, scrotum, urethra and various glands like prostate gland, seminal vesicle.
- Testes: Testes are located outside body in the scrotum, where male germ cells i.e sperms are produced. Secretes hormone testosterone which brings changes in appearance during puberty.
- Vas deferens: Sperms are delivered through vas deferens. It unite with urethra. Vas deferens receives secretion from prostate gland and seminal vesicle, which provides transport and nourishment to sperms.
- Sperm Cell: Consist of genetic material and a long tail which help them to move towards female germ-cell.
- Ovaries: Female germ cells called eggs are produced in ovaries. Ovaries contains thousands of egg cells which starts to mature at time of puberty. One ovary produces one egg every month.
- Fallopian tube: Open into uterus. While uterus opens into vagina through cervix. Eggs from ovaries are carried from ovaries to womb through fallopian tube. Sperms enter through vaginal passage and reach fallopian tube, where fertilization takes place, forming zygote.
- Zygote develops into embryo. Embryo receives nutrition through mother’s blood with help of placenta. Child lives in mothers womb for nine months and is born by rhythmic contraction of muscles in uterus.
- Contraceptive Methods : Methods avoids fusion of male and female gametes.
- Some reasons for adopting contraceptive methods :
- Mental readiness for taking responsibility.
- Family pressure.
- Government rules.
- To avoid sexually transmitted disease. E.g. AIDS.
- To avoid pregnancy, incase if women is not ready mentally, pregnancy will affect her health.
- Mechanical Barriers : Use of condoms in males and similar covering in females avoids entry of male gametes in female body and also prevents sexually transmitted diseases.
- Changing hormonal balance : Use of oral pills changes the hormonal balance due to which eggs are not released and no fertilization takes place. Use of these pills causes side effects on body.
- Copper T : Prevents release of eggs and thereby preventing fertilization. It causes irritation in the uterus.
- Surgical methods : In female, fallopian tube is blocked, hence, eggs are not released. In males, vas deferens is blocked, hence, sperms are not released. It can cause infections in the body.
- Abortion : Act of removing fetus from the body. An illegal act which is mainly misused to abort girl child.