Sexual Reproduction Notes PDF

SEXUAL REPRODUCTION Reproduction Definition: The process by which living things produce offspring of their own kind. Importance: Ensures the continuation of species. Types: o Asexual Reproduction: Involves a single parent. Examples include: ▪ Budding:...

SEXUAL REPRODUCTION Reproduction Definition: The process by which living things produce offspring of their own kind. Importance: Ensures the continuation of species. Types: o Asexual Reproduction: Involves a single parent. Examples include: ▪ Budding: Offspring grows out of the parent's body (e.g., Hydra). ▪ Binary Fission: The parent splits into two (e.g., Amoeba). o Sexual Reproduction: Involves the fusion of male and female gametes. Examples include: ▪ Internal Fertilization: Fertilization occurs inside the female's body (e.g., humans, mammals). ▪ External Fertilization: Fertilization occurs outside the female's body (e.g., fish, amphibians). Additional Points Metamorphosis: The process of transformation from an immature form to an adult form (e.g., insects, amphibians). Reproductive System: Though not essential for the immediate survival of an individual, it is crucial for the continuation of the species. Certainly, let's break down the information presented in the image you sent: Reproduction in Animals Types of Reproduction Asexual Reproduction: Involves a single parent. Examples include: o Budding: Offspring grows out of the parent's body (e.g., Hydra). o Binary Fission: The parent splits into two (e.g., Amoeba). Sexual Reproduction: Involves the fusion of male and female gametes. Examples include:  o Internal Fertilization: Fertilization occurs inside the female's body (e.g., humans, mammals). o External Fertilization: Fertilization occurs outside the female's body (e.g., fish, amphibians). Sexual Reproduction in Animals Gametes: o Male: Sperm cells o Female: Egg cells (ova) Hermaphrodites: Organisms that have both male and female reproductive organs (e.g., earthworms, leeches). Fertilization: The fusion of sperm and egg to form a zygote. o External Fertilization: Occurs outside the female's body (e.g., fish, amphibians). o Internal Fertilization: Occurs inside the female's body (e.g., birds, reptiles, mammals). Reproduction in Humans Involves two sexes: male and female. Internal fertilization. Development of the zygote into a fully formed individual occurs inside the body of the female. Here are the notes from the cropped images focusing on the human reproductive system: Human Reproductive System Male Reproductive System Organs: o Testes: Located in the scrotum, responsible for producing sperm and testosterone. o Scrotum: A sac that holds the testes outside the body to maintain a cooler temperature for sperm production. o Epididymis: Coiled tubes attached to the testes where sperm mature andare stored. o Vas Deferens: Tubes that carry sperm from the epididymis to the ejaculatory ducts.  o Seminal Vesicles: Glands that secrete fluids containing nutrients and fructose to nourish sperm. o Prostate Gland: A gland that contributes to the semen's volume and alkalinity. o Urethra: The tube that carries both urine and semen. o Penis: The external organ that delivers sperm into the vagina. Male reproductive system sperm cell Female Reproductive System Organs: o Ovaries: Produce eggs (ova) and hormones (estrogen and progesterone). o Oviducts (Fallopian Tubes): Tubes that carry eggs from the ovaries to the uterus. Fertilization typically occurs in the oviduct. o Uterus: The muscular organ where a fertilized egg implants and develops into a fetus. o Vagina: The muscular canal that receives sperm during intercourse and serves as the birth canal. o Cervix: The opening to the uterus. Female reproductive system Puberty The onset of sexual maturity. In males, puberty is marked by voice deepening, facial/body hair growth, muscle development, and sperm production. In females, puberty is marked by breast development, hip widening, and menstruation. Fertilization The fusion of a sperm and an egg. Occurs in the oviduct. The fertilized egg (zygote) travels to the uterus and implants in the uterine wall. Key Hormones Male: Testosterone Female: Estrogen and Progesterone Notes Sperm are produced in millions, each a single cell with a head, middle piece, and tail. Ovulation is the release of an egg from the ovary. The mixture of sperm and fluids is called semen. Fertilization and Zygote Formation Fertilization: The fusion of a sperm cell from the father and an egg cell (ovum) from the mother. Zygote: The fertilized egg. It contains genetic material from both parents. P.T.O -> Development of the Embryo Cell Division: After fertilization, the zygote travels down the oviduct and undergoes rapid cell division, forming a ball of cells. Differentiation: The cells start to specialize into different types of cells (e.g., muscle cells, nerve cells, blood cells) to form various tissues and organs of the body. Embryo: The developing structure in the early stages of development (up to 8 weeks). Fetus: The developing structure from the 9th week of pregnancy onwards. Implantation The embryo implants itself in the lining of the uterus (endometrium). This lining is rich in blood vessels to provide nourishment to the developing embryo. Development of the Fetus The fetus continues to grow and develop within the uterus. Different organs and systems develop during this stage. The fetus receives nutrients and oxygen through the placenta. Test Tube Baby (IVF) A technique used to help couples who are unable to conceive naturally. Involves collecting eggs from the woman's ovaries and sperm from the man. The sperm and eggs are combined in a laboratory dish to allow fertilization to occur. The resulting embryo is then transferred into the woman's uterus. Key Points The zygote inherits characteristics from both parents. Cell differentiation is crucial for the development of various tissues and organs. IVF is a technology that helps couples overcome infertility. Viviparous and Oviparous Animals Viviparous Animals: Animals that give birth to fully formed young ones. Examples include humans, cows, goats, dogs, and other mammals. Oviparous Animals: Animals that lay eggs. Examples include birds, reptiles, fish, and amphibians. Development in Oviparous Animals After fertilization, the zygote undergoes repeated cell divisions and develops within an egg. The egg provides protection and nourishment to the developing embryo. The embryo hatches from the egg after a period of development. Development in Viviparous Animals Fertilization takes place internally. The zygote develops inside the mother's body. The mother provides nourishment and protection to the developing embryo. The fully developed young one is born. Key Points Viviparous animals give birth to live young, while oviparous animals lay eggs. The mode of reproduction is related to the level of parental care and protection provided to the offspring. Certainly, let's break down the information presented in the image you sent: Metamorphosis Definition: The complete change in form of an animal as it develops from a young one into an adult.  Examples: o Frog: Egg → Tadpole (larva) → Frog (adult) o Mosquito: Egg → Larva → Pupa → Adult o Butterfly/Moth: Egg → Larva (caterpillar) → Pupa (chrysalis) → Adult Asexual Reproduction Definition: Reproduction involving only one parent. It does not require the involvement of two sexes. Types: o Binary Fission: A single-celled organism divides into two identical daughter cells. Example: Amoeba. o Budding: A small outgrowth (bud) forms on the parent organism, grows, and eventually separates to become a new individual. Example: Hydra. Key Points Metamorphosis is a significant developmental process in many animals, allowing them to adapt to different stages of life. Asexual reproduction enables some organisms to reproduce rapidly without the need for a mate. The Story of Cloning Dolly the Sheep: A landmark scientific achievement where a sheep named Dolly was cloned in 1997. Cloning Process: o A cell was taken from the mammary gland of a female sheep. o The nucleus of this cell, containing the genetic material, was removed. o An unfertilized egg was taken from another female sheep. o The nucleus of the unfertilized egg was removed. o The nucleus from the mammary gland cell was inserted into the egg cell. o The egg cell with the new nucleus started to develop as if it had been fertilized. o This embryo was then implanted into the uterus of a third female sheep, where it developed into a baby sheep. Significance of Dolly: Dolly was the first mammal to be cloned from an adult somatic cell. This breakthrough opened up new possibilities in genetic research and medicine. Limitations of Cloning: Cloning has been attempted in other animals, but success has been limited. Cloned animals often have health problems or die prematurely.