Reproduction Notes PDF

REPRODUCTION Handwritten Notes Made with by GAURAV SUTHAR The production of new organism form the already existing organism of the same species is known as Reproduction. - The process of reproduction ensures continuity of life on earth. - Reproduction is essential for the surv...

REPRODUCTION Handwritten Notes Made with by GAURAV SUTHAR The production of new organism form the already existing organism of the same species is known as Reproduction. - The process of reproduction ensures continuity of life on earth. - Reproduction is essential for the survival of a species on this earth. - The production of a new organism from a single parent without the involvement of sex cells (or gametes) is called asexual reproduction. - The production of a new organism from two parents by making use of their Sex cells (or gametes) is called Sexual reproduction. Ques - Differentiate between Asexual Reproduction and Sexual Reproduction. - In this process of fission, a unicellular organism splits or divides into two or more new organism. - The breaking up of the body of a simple organism into two or more pieces on maturing, each of which subsequently grows to form a complete new organism, is called fragmentation. - Example – Spirogyra  + Fig. Fragmentation in Spirogyra Real photo of Fragmentation in Spirogyra The process of getting back a full organism from its body parts is called Regeneration. Example - Hydra and Planaria  Real photo of Planaria - In budding, a small part of the body of the parent organism grows out as a 'bud' which then detaches and becomes a new organism. - Example - Hydra  Real photo of budding in Hydra − The parent plant produces hundred of microscopic reproductive units called 'spores'. When the spore case of the plant bursts, then the spores spread into air. When these air-borne spores land on food (or soil) under favourable conditions (like damp and warm conditions), they germinate and produce new plants. − Example - Rhizopus Real photo of Spore Formation in Rhizopus − In Vegetative propagation, new plants are obtained from the parts of old plants (like Stem, roots and leaves) without the help of any Reproductive organs. − Sexual Reproduction involves the fusion of gametes or sex cells resulting in the formation of zygote − Due to the fusion of gametes, the chances of variations are very high during sexual reproduction Ques - What is the advantage of Sexual reproduction? Ans – Sexual reproduction results in genetic variation which ultimately leads to evolution of new species. The Sex Organs (or reproductive organs) of a plant are in its flowers.  It is the male reproductive part of the flower. It is composed of two parts - Anther and Filament. Stamen produces pollen grains that are yellow in colour. It is the female reproductive part of the flower. It is composed of three parts - Ovary, Style and Stigma. Ovary : The swollen bottom part Style : Middle elongated part Stigma : Terminal sticky part The green, leaf-like parts of the flower are called Sepals. Its function is to protect the flower in its initial stages. The colourful parts of a flower are called Petals.  Its function of petals is to attract insects for pollination and to protect the reproductive organs. Real photo of parts of Flower Contains either Stamens or Pistil Example - Papaya, Watermelon Contains both Stamens and Pistil Example - Hibiscus, Mustard The transfer of pollen grains from anther of a stamen to the stigma of a carpel is called pollination. - Pollination can be of two types: The pollen grains from the anther of a flower are transferred to the Stigma of the same flower (or another flower of the same plant) The pollen grains from the anther of a flower on one plant are transferred to the Stigma of a flower of another similar plant. Fertilization occurs when the male gamete present in the pollen grain joins with the female gamete (or egg) present in ovule.  Easy Diagram of Ovary Both Diagrams are of same thing but Left Diagram is of NCERT book And the Right Diagram is easy to understand  Complete process of Reproduction in Flower Just in one Diagram After fertilization, the zygote divides several times to form an embryo within the ovule. The ovule develops a tough coat and is converted into Seed.  The ovary grows rapidly and ripens to form a form of Fruit. The Seed contains the future plant which develops into a Seedling. The radicle grows to form the root. Plumule grows upward to form the shoot. Cotyledon contains stored food that helps radicle and plumule to grow.  The age at which the Sex hormone and gametes begin to be produces and the Boy and Girl become sexually mature is called Puberty. In males, after Puberty, testes starts producing sperms and the Male sex hormone called Testosterone. In females, after puberty, ovaries starts producing Ova (or eggs) and Female sex hormone, Estrogen. Male and female also starts developing secondary sexual characters. Secondary Sexual characters in Male : a. Hair grow in Armpits, Pubic regions, Chest and Face b. Body becomes muscular. c. The voice deepens. d. Chest and Shoulders broaden. Secondary Sexual characters in Female : a. Hair grow in Armpits and Pubic regions. b. Mammary glands develop and enlarge. c. Hips broaden. d. Fallopian tube, uterus and Vagina enlarge.  The male reproductive system consists of portions which perform two major functions- - Produce sperms – Testes - Deliver sperms to the site of fertilization - All the rest (Vas deferens, Seminal Vesicle, Prostrate) − It is primary reproductive organ in male.  − It is located outside the abdominal cavity in scrotum because sperm formation requires a lower temperature than the normal body temperature. Functions of Testes – Formation of Sperms. Secretion of testosterone. − Vas deferens delivers sperms from testes to urethra. − Both of these gland add fluid secretions to the sperms which makes the transport of sperms easier and provides nutrition. − Forms a common passage for both Sperms and Urine. Human Body: Reproductive System The male and female reproductive systems are controlled by hormones produced by the pituitary gland in the brain, and the reproductive organs themselves. Brain The Reproductive Organs These organs make, mature, and store gametes, or sex cells, in the human body. The male gametes are called sperm and female gametes are called ova or egg cells. Each gamete contributes half of an offspring’s DNA, providing genetic variation through hypothalamus sexual reproduction. Male reproductive system Pituitary gland Sperm is made in the seminiferous tubules and stored in the spinal cord epididymis. It travels through the vas deferens, where it mixes with seminal fluids and passes through the urethra. infundibulum ureters anterior posterior pituitary pituitary vas deferens epididymis Pituitary Gland bladder head The pituitary gland secretes hormones that control the reproductive organs. It signals the production of sex prostate hormones and controls ovulation and the menstrual cycle in women. urethra penis testis epididymis body seminiferous tubules epididymis tail Female reproductive system Immature eggs are found in the ovaries where they mature and are Developing released into the fallopian tubes. An egg travels down the tube to Ovarian Follicle the uterus, where it either implants and develops into an embryo or is shed with the lining of the uterus at the end of a menstrual cycle. fallopian tubes ovary ovary mature uterus egg vagina © 2017 Carolina Biological Supply Company − It is the primary reproductive organ in female. It performs two major functions Production of - Egg/ Ovum. Secretion of Estrogen and Progesterone − One egg is produced every month by ovaries. − It is the primary reproductive organ in female. It performs two major functions − It acts as a site of fertilization. − The Oviducts unite into an elastic - bag like structure known as the uterus. − Uterus opens into the vagina through cervix. − It receives sperms from male partner, serves as a Birth Canal. − Uterus is connected to vagina through a narrow opening called Cervix. - The sperms enter through the vaginal passage during sexual intercourse. - They travel upwards and reach the oviduct where they may encounter egg. - The fertilized egg (zygote) starts diving to form a ball of cells or embryo. - The embryo is implanted in the lining of the uterus where they continue to grow and develop organs to become foetus. - The embryo gets nutrition from the mother's blood with the help of a special tissue called Placenta. - The development of the child inside the mother's body takes approximately nine months (Gestation period). The child is born as a result of rhythmic contractions of the muscle in the uterus. - Every month, Ovary releases one egg and uterus prepares itself to receive the fertilised egg by developing thick, spongy lining. - If fertilisation doesn't take place, egg along with the uterus lining breaks down and comes out through vagina as blood and mucus. - This cycle takes place roughly every month and is known as Mensuration. - It lasts for about 2-8 days. - Diseases which are spread by sexual contact with an infected person are called Sexually Transmitted Diseases (STD). - Common STD are: Gonorrhoea Syphills Caused by Bacteria AIDS (Acquired Immune Deficiency Syndrome) Caused by Virus − The prevention of pregnancy in Women is called Contraception. Condoms Advantage : It helps in the prevention of STD Oral pills Disadvantage : It changes hormonal balance which can cause side effects. Copper -T Disadvantage : Can cause irritation of uterus. Vasectomy Tubectomy Blocking of Vas deferens in male Blocking of fallopian tube in females. - Surgical methods are safe in the long run but surgery itself can cause infections if not performed properly.