Biology Unit 16 - Reproduction in Plants

Comprehensive flashcards covering plant reproduction, including sexual and asexual methods, floral anatomy, pollination, and germination based on the lecture notes.

Sexual reproduction

Process that involves the reproduction and fusion of two gametes (reproductive cells).

Asexual reproduction

Reproduction that involves no fertilization and no fusion of gametes, usually occurring through mitosis.

Gametes

Sex cells found in higher plants and animals; the male gamete is smaller and motile, while the female gamete is larger and non-motile.

Mitosis

A process in which a cell divides to produce daughter cells with the same number of chromosomes and identical genetic material, called clones.

Maize chromosome number

The number of chromosomes in Maize is $20$, resulting in $10$ gamete chromosomes.

Man chromosome number

The number of chromosomes in humans is $46$, resulting in $23$ gamete chromosomes.

Rhizome

An underground stem with dry scaly leaves and buds, such as ginger.

Bulbs

Modified shoots consisting of fleshy and dry scaly leaves on a flattened stem, such as onions.

Corm

A thick, short, and swollen underground stem, such as a water chestnut.

Tuber

A swollen underground stem, such as a potato.

Vegetative propagation

Asexual reproduction where a new plant grows from an old plant using underground storage organs like rhizomes, bulbs, corms, tubers, and runners.

Perennation

The survival of a plant from year to year; underground storage organs used for this are called perennating organs.

Cutting

An artificial method of vegetative reproduction where a plant is cut below a node to allow it to develop roots and form a new plant.

Layering

A method where a low branch with a node is bent down, a ring of bark approximately $5\,cm$ wide is removed, and it is covered with soil until roots develop.

Marcotting

A method involving the removal of a ring of bark and wrapping it in moist soil until roots appear, then cutting and planting it.

Stock

A plant with well-developed roots selected to have a scion attached during budding or grafting.

Scion

The portion of a new plant to be propagated that is attached to a stock during grafting or budding.

Inflorescence

A cluster of flowers arranged in definite patterns on a stem called an inflorescence stalk.

Pedicel

The stalk of an individual flower; flowers without this are called sessile flowers.

Receptacle

The enlarged end of a flower stalk on which other floral parts are borne.

Sepals

Modified leaves that protect the flower in the bud stage; collectively they form the calyx.

Petals

Modified leaves that form the conspicuous corolla of a flower, often brightly colored to attract insects.

Epicalyx

An extra whorl of floral leaves found outside the sepals in some flowers, such as hibiscus.

Perianth

The collective term for the calyx and corolla; used when sepals and petals are indistinguishable.

Stamen (Androecium)

The male part of a flower consisting of a filament and an anther where pollen grains are produced by meiosis.

Pollen grains

Structures produced in pollen sacs that give rise to two haploid male gametes.

Pistil (Gynoecium)

The female part of a flower consisting of one or more carpels, each containing an ovary, style, and stigma.

Stigma

The swollen end of the style that receives pollen grains.

Placenta

The region in the ovary to which the ovule is attached via the funicle.

Hermaphrodite (Bisexual)

A flower that possesses both stamen and pistil.

Monoecious

A plant that possesses both male and female unisexual flowers on the same individual, such as maize.

Dioecious

A species where male and female flowers are borne on separate plants, such as papaya.

Pollination

The transfer of pollen grains from the anther to the stigma.

Standard petal

The large purple petal in a Clitoria flower, often containing nectar guides.

Nectar

A sugary fluid produced by flowers to attract insects, often collecting at the bottom of a stamen trough.

Lodicules

Tiny structures in grass flowers that swell to force flowering bracts apart, allowing stigma and anther to emerge.

Glumes

Non-flowering bracts at the base of a grass spikelet.

Pollen tube

A structure that grows from a germinating pollen grain down the style to enter the ovule through the micropyle.

Micropyle

The small opening in the ovule wall through which the pollen tube enters.

Testa

The seed coat, which is formed from the integument of the ovule.

Pericarp

The fruit wall, which is formed from the ripened ovary wall.

Loculi

Individual fruit chambers within an ovary.

Epigeal germination

A type of germination where the cotyledons are carried above the ground, such as in sword bean seeds.

Hypogeal germination

A type of germination where the cotyledons remain below the soil, such as in maize.

Radicle

The part of the plant embryo that develops into the primary root.

Plumule

The part of the plant embryo that develops into the shoot.