Class 10 Science: How Do Organisms Reproduce

Comprehensive vocabulary flashcards covering plant and human reproduction, modes of asexual propagation, sexual reproduction stages, anatomy, and contraception based on Class 10 Science notes.

Reproduction

The biological process of creating new life from existing life, which replaces deceased organisms and ensures the continuity of life on Earth.

DNA Replication

The process during reproduction that preserves body structure, facilitates the inheritance of traits, and introduces variation essential for evolutionary processes.

Variation

Differences occurring in DNA replication that enable organisms to adapt to changing environments, contributing to the stability and survival of a species population.

Asexual Reproduction

A reproductive process wherein offspring are produced by a single parent, with or without the involvement of gamete formation.

Binary Fission

A type of fission in unicellular organisms, such as Amoeba, where the nucleus divides followed by the cytoplasm to split the parent into two identical daughter cells.

Multiple Fission

A division mechanism in which an organism, such as the malarial parasite Plasmodium, divides into numerous identical daughter cells simultaneously within a cyst.

Fragmentation

The process wherein a simple multicellular organism (such as Spirogyra) matures and breaks into two or more pieces, each growing independently into a new organism.

Budding

A mode of asexual reproduction where small outgrowths called buds develop via repeated mitotic division on the parent body, mature, and detach to live independently (e.g., Hydra, yeast).

Vegetative Propagation

A method of developing new plants from vegetative parts—such as roots, stems, or leaf buds—of an old plant without the involvement of reproductive structures.

Cutting

An artificial propagation method involving the removal of a small portion of a plant with a sharp knife to grow a new individual, used in sugarcane, bananas, and cactus.

Layering

An artificial propagation technique where a branch is bent to the ground and covered with soil while leaving the tip exposed, observed in Jasmine and lemon.

Grafting

An artificial propagation method in which the stems of two plants (one rooted and one unrooted) are joined together to grow as a single unified plant (e.g., apple, pear).

Tissue Culture

A rapid laboratory technique where small pieces of plant tissue or cells are cultivated in a nutrient-rich medium with hormones to produce large quantities of disease-free plants in weeks.

Callus

The shapeless lump or unorganized mass of proliferating cells formed during tissue culture before differentiation into roots and shoots.

Regeneration

The biological reconstruction of a complete organism from a specific severed body part utilizing specialized regenerative cells, as seen in simple organisms like Planaria.

Spore Formation

An asexual reproduction method where a parent plant (e.g., Rhizopus) produces microscopic reproductive units called spores within a sporangium, which disperse in air and germinate under favorable conditions.

Sexual Reproduction

A reproductive process involving the union of two specialized germ cells (male sperm and female egg) to produce a zygote that develops into a genetically distinct offspring.

Bisexual Flower

A flower that contains both male reproductive organs (stamens) and female reproductive organs (carpels) within the same floral structure.

Unisexual Flower

A flower that possesses either male reproductive structures (stamens) or female reproductive structures (carpels), but not both within the same blossom.

Stamen

The male reproductive organ of a flower consisting of a filament and an anther containing pollen sacs that produce pollen grains.

Carpel

The central female reproductive organ of a flower, also called the pistil, composed of three main structures: the stigma, style, and ovary.

Stigma

The sticky, terminal landing platform at the top of the carpel designed to receive pollen grains during pollination.

Pollination

The external transfer of pollen grains from the anther of the stamen to the receptive stigma of a flower via wind, water, or animals.

Fertilization

The internal biological fusion of the male gamete with the female gamete to form a single diploid cell called a zygote.

Puberty

The developmental stage marked by sex hormone secretion and physical maturation, occurring at approximately $13-14\text{ years}$ in boys and $10-12\text{ years}$ in girls.

Testosterone

The primary male sex hormone synthesized and secreted by the testes that regulates sperm development and secondary male sexual characteristics.

Scrotum

An external pouch of skin housing the testes outside the abdominal cavity to maintain a temperature $1-3\,^\circ\text{C}$ lower than core body temperature, required for sperm production.

Vas Deferens

The muscular tube that conveys mature sperm from the testes toward the urethra, joining the duct emerging from the urinary bladder.

Prostate Gland and Seminal Vesicles

Accessory male glands that secrete nutrient-rich fluids providing nourishment and facilitating easier movement for sperm in semen.

Ovaries

Paired oval organs in the female abdominal cavity that produce ova (egg cells) and secrete the female sex hormones estrogen and progesterone.

Fallopian Tube

The oviduct featuring a funnel-shaped opening near the ovary that transports eggs to the uterus and serves as the primary site for fertilization.

Uterus

A hollow, pear-shaped muscular organ inside the female body where the fertilized embryo implants and develops throughout the gestation period.

Cervix

The lower, narrow portion of the uterus that connects the uterine cavity to the vagina.

Implantation

The attachment process wherein the dividing embryo embeds itself firmly into the thickened, soft lining of the uterus.

Placenta

A specialized vascular disc tissue embedded in the uterine wall with embryonic villi, facilitating the transport of nutrients, gases ($O_2$ and $CO_2$), and wastes between mother and fetus.

Menstruation

The recurring monthly discharge of blood, mucous, and broken-down uterine lining through the vagina lasting roughly $2-8\text{ days}$ when an ovulated egg remains unfertilized.

Contraception

The deliberate use of artificial methods, barrier devices, chemicals, or surgical techniques to prevent unwanted fertilization and pregnancy.

Intrauterine Devices (IUDs)

Contraceptive devices, such as the Loop or Copper-T, inserted directly into the female uterus to mechanically and chemically prevent pregnancy.

Vasectomy

A surgical contraceptive method for males in which the vas deferens is cut or blocked to prevent the passage and discharge of sperm.

Tubectomy

A permanent surgical contraceptive method in females wherein the fallopian tubes are blocked or severed to prevent eggs from reaching the site of fertilization.

Sexually Transmitted Diseases (STDs)

Infections transmitted through direct sexual contact, including viral and bacterial conditions such as AIDS, gonorrhea, and genital warts.

Reproduction

The biological process of creating new life from existing life, which ensures the continuity of life on Earth and replaces deceased organisms.

DNA (Deoxyribonucleic Acid)

The genetic material shared between parents and offspring that preserves body structure, facilitates trait inheritance, and creates resemblance among generations.

Variation

Subtle genetic differences introduced during DNA replication that enable organisms to adapt to changing environments and contribute to the survival and resilience of populations.

Asexual Reproduction

A reproductive process wherein a single parent gives rise to offspring, with or without the involvement of gamete formation.

Binary Fission

A form of fission in unicellular organisms (such as Amoeba) where the nucleus divides into two, followed by cytoplasmic division, splitting the parent cell into two daughter cells.

Multiple Fission

A reproductive mechanism in which a unicellular parent organism divides simultaneously into numerous identical daughter cells, as seen in Plasmodium.

Fragmentation

The asexual process wherein a simple multicellular organism (such as Spirogyra) breaks into two or more pieces upon maturity, each piece developing independently into a new individual.

Budding

A reproductive process in which small outgrowths called buds form on the parent organism via mitotic division of regenerative cells, develop, and eventually detach to live as independent organisms (e.g., Hydra, yeast).

Vegetative Propagation

A method of producing new plants from vegetative structures of an old plant (such as roots, stems, or leaves) without the involvement of seeds or flower reproductive structures.

Cutting

An artificial propagation method involving the removal of a small vegetative part of a plant using a sharp knife to produce new individuals (e.g., sugarcane, bananas, cactus).

Layering

An artificial propagation method in which a branch is bent toward the ground and buried in soil with its tip exposed until roots develop (e.g., jasmine, lemon).

Grafting

An artificial propagation technique where the stems of two distinct plants—one with roots and the other without—are joined together to grow as a single plant (e.g., apple, pear).

Tissue Culture

A rapid laboratory method of growing new, disease-free plants within weeks using a tiny piece of plant tissue or cells taken from a growing tip cultured in a nutrient-rich medium.

Callus

An unorganized, shapeless mass of dividing cells formed in tissue culture before the induction of roots and shoots in hormone-treated media.

Regeneration

The asexual process of reconstructing a complete organism from a severed body part, viable in organisms with simpler body designs such as Planaria.

Spore Formation

A reproductive method where a parent plant (e.g., Rhizopus) develops microscopic reproductive units called spores within a sporangium, which burst and disperse through the air to germinate under favorable conditions.

Sexual Reproduction

A mode of reproduction involving the union of two specialized reproductive cells (male and female gametes) to form a zygote that develops into a new organism.

Bisexual Flower

A flower that contains both male reproductive organs (stamens) and female reproductive organs (carpels) within the same structure.

Unisexual Flower

A flower that possesses either male reproductive structures (stamens) or female reproductive structures (carpels), but not both.

Stamen

The male reproductive organ of a flowering plant, consisting of an anther and a filament.

Anther

The two-lobed structure situated at the tip of the stamen containing pollen sacs that produce yellowish pollen grains.

Carpel

The centrally located female reproductive organ of a flower, consisting of the stigma, style, and ovary.

Stigma

The terminal, often sticky surface of the carpel adapted to receive pollen grains during pollination.

Style

The elongated middle neck of the carpel through which the pollen tube grows to connect the stigma to the ovary.

Ovary (Flower)

The swollen basal part of the carpel containing ovules (which house the egg cell); it later ripens into a fruit after fertilization.

Pollination

The transfer of pollen grains from the anther of a stamen to the receptive stigma of a flower via agents like wind, water, or animals.

Self-Pollination

The transfer of pollen grains from the anther to the stigma of the exact same flower.

Cross-Pollination

The transfer of pollen grains from the anther of one flower to the stigma of a different flower.

Fertilization

The internal biological fusion of a male gamete with a female gamete (ovum/egg) to form a single diploid cell known as a zygote.

Puberty

The developmental phase characterized by the production of sex hormones and the attainment of sexual maturity, typically occurring at $13\text{–}14\text{ years}$ in boys and $10\text{–}12\text{ years}$ in girls.

Testosterone

The primary male sex hormone synthesized by the testes, responsible for regulating sperm production and secondary sexual characteristics.

Estrogen and Progesterone

The female sex hormones produced by the ovaries that regulate reproductive functions, menstrual cycles, and secondary sexual characteristics.

Testis

The primary male reproductive organ that produces sperm (exocrine function) and secretes testosterone (endocrine function).

Scrotum

The external pouch containing the testes outside the abdominal cavity, keeping them at a temperature $1\text{–}3^\bot\text{C}$ lower than core body temperature for optimal sperm production.

Vas Deferens

The muscular tube that conveys mature sperm from the testes to join the duct from the urinary bladder.

Urethra

A common tube in human males that carries urine from the bladder and serves as the exit canal for semen during ejaculation.

Prostate Gland and Seminal Vesicle

Male reproductive accessory glands that secrete fluid to nourish sperm and facilitate their easier mobility.

Ovary (Human)

Paired oval organs situated in the female abdominal cavity that produce thousands of ova (egg cells) and secrete estrogen and progesterone.

Fallopian Tube (Oviduct)

The tubular structure with a funnel-shaped opening near the ovary that transports eggs to the uterus and serves as the normal site of fertilization.

Uterus (Womb)

A hollow, pear-shaped muscular organ inside the female pelvis where implantation occurs and the fetus develops during the nine-month gestational period.

Cervix

The lower, narrow neck-like portion of the uterus that connects and opens directly into the vagina.

Vagina

The female muscular canal that receives sperm during copulation and functions as the birth canal during delivery.

Implantation

The biological process in which the developing embryo embeds itself securely into the thickened, spongy inner lining of the uterus.

Placenta

A specialized disc-like tissue connecting the uterine wall and embryo, equipped with villi and blood spaces to facilitate nutrient transfer, gas exchange, and waste removal.

Menstruation

The monthly shedding and expulsion of the unneeded, thickened uterine lining through the vagina as blood and mucous, lasting approximately $2\text{ to }8\text{ days}$ when an egg is unfertilized.

Contraception

The deliberate prevention of pregnancy through mechanical barriers, chemical or hormonal methods, intrauterine devices, or surgical interventions.

Intrauterine Device (IUD)

A contraceptive device, such as a Copper-T or loop, inserted into the uterus by medical practitioners to prevent pregnancy.

Vasectomy

A permanent surgical birth control method for males where the vas deferens is cut or blocked to prevent the passage of sperm.

Tubectomy

A permanent surgical birth control method for females where the fallopian tubes are blocked to prevent eggs from meeting sperm.

Sexually Transmitted Diseases (STDs)

Infections transmitted through sexual contact, including bacterial infections like gonorrhea and viral infections like AIDS and genital warts.