HSC Biology Module 5: Reproduction and Continuity of Species

Vocabulary practice flashcards covering asexual reproduction (budding, spores, binary fission, vegetative propagation), sexual reproduction in plants, external vs internal animal fertilisation, and mammalian reproductive endocrinology (menstrual cycle, pregnancy, and birth).

Budding

A form of asexual reproduction where a small outgrowth develops on the parent organism, receives a replicated nucleus, and eventually detaches to form a genetically identical offspring (e.g., in yeast and hydra).

Sporangia

Specialised fungal structures that produce and house large quantities of microscopic, lightweight spores.

Spores (Fungi)

Lightweight microscopic reproductive units produced in sporangia that are dispersed over long distances by wind or water and germinate into new organisms under favourable conditions.

Binary Fission

The primary method of asexual reproduction in bacteria and protists (such as Amoeba) where a single cell replicates its DNA, elongates, and divides into two genetically identical daughter cells.

Angiosperms

Flowering plants whose seeds develop enclosed within fruits.

Gymnosperms

Woody, seed-producing plants whose seeds are not enclosed inside a fruit (e.g., pines).

Pollination

The transfer of pollen grains containing male gametes from the male anther to the receptive female stigma of a flower.

Stamen

The male reproductive structure of a flower, consisting of the anther (where pollen is produced) supported by a filament.

Carpel

The female reproductive structure of a flower, comprising the sticky stigma, the supporting style, and the ovary where ovules are formed.

Vegetative Propagation

A form of asexual reproduction in plants where new individuals grow directly from structural parts of the parent plant (such as stems, roots, or leaves) rather than developing from seeds.

Runners (Stolons)

Horizontal aboveground stems produced by plants such as strawberries that spread out from the parent to establish new, genetically identical plantlets.

Tubers

Underground swollen storage organs, such as those found in potatoes, that provide nutrients and sprout to produce new independent plants.

Cuttings

An artificial vegetative propagation method where a severed piece of parent stem, leaf, or root is planted in soil or compost to regenerate an entire new plant.

External Fertilisation

A reproductive strategy wherein male and female gametes are discharged into an external aquatic environment where fusion takes place outside the female body (common in fish and amphibians).

Internal Fertilisation

A reproductive strategy in which sperm are introduced directly into the female reproductive tract, allowing the fusion of gametes to occur inside the female body in a protected environment.

Endometrium

The specialized inner lining of the uterus that thickens under hormonal regulation to accommodate the implantation of an embryo.

Fertilisation (Mammalian)

The fusion of the nuclei of a haploid sperm and a haploid ovum (each contributing $23$ chromosomes) within the fallopian tube to form a diploid zygote.

Implantation

The attachment and embedding of the developing blastocyst/embryo into the endometrium of the uterus wall within seven days of fertilisation.

Follicle Stimulating Hormone (FSH)

An anterior pituitary hormone that stimulates the recruitment, growth, and maturation of ovarian follicles containing developing ova.

Luteinising Hormone (LH)

An anterior pituitary hormone whose rapid mid-cycle surge triggers ovulation and promotes the transformation of the ruptured follicle into the corpus luteum.

Corpus Luteum

A temporary endocrine structure formed from the ruptured follicle in the ovary that secretes progesterone and oestrogen to maintain the endometrium after ovulation.

Human Chorionic Gonadotropin (HCG)

A pregnancy hormone secreted by the placenta that signals successful implantation, halts monthly follicular development in the ovaries, and maintains the corpus luteum to preserve progesterone production.

Progesterone

A steroid hormone produced by the corpus luteum and placenta that maintains the thickened endometrium, supports implantation, and suppresses uterine muscle contractions during pregnancy.

Oestrogen

A hormone produced by developing follicles and later the placenta that thickens the endometrium, increases uterine blood supply, and upregulates uterine oxytocin sensitivity before labor.

Oxytocin

A pituitary hormone that drives a positive feedback loop during childbirth by stimulating strong, rhythmic contractions of the uterine muscle to push the baby through the cervix.

Prostaglandins

Hormonally active lipid compounds produced during labor that soften and dilate the cervix while enhancing uterine muscle contractions.

Relaxin

A hormone active during birth that aids cervical dilation and relaxes the maternal pelvic ligaments to ease delivery of the fetus.

Prolactin

A pituitary hormone responsible for stimulating and sustaining milk synthesis in the mammary glands following birth.