Seeds

Placentation

The arrangement or attachment of ovules inside the ovary; the placentation of the ovary reflects that of the fruit

Marginal Placentation

Seeds are attached on one side of the fruit, along the margin (e.g., bean pod)

Axile Placentation

Ovules are attached to a central axis, with many locules and chambers (e.g., tomato, orange)

Parietal Placentation

Seeds are attached all over the inner wall (parietal) of the ovary (e.g., papaya)

Free Central Placentation

Ovules are attached to a central column in a single locule, without any partition walls, appearing as if seeds are floating

Basal Placentation

A single ovule is attached at the base of the ovary

Seed

The mature ovule which develops into an embryo (a very young plant) after fertilization and rounds of mitosis

Embryo

A very young plant formed from the zygote after fertilization and several rounds of mitosis; contains structures such as terminal cell, protoderm, procambium, ground meristem, cotyledon, shoot apex, root apex, hypocotyl, and epicotyl

Seed Coat

The protective outer covering of a seed, which shields the embryo and endosperm inside

Endosperm

The tissue within the seed that provides nourishment to the developing embryo; it is especially prominent in monocots and is rich in carbohydrates

Cotyledon

The seed leaf or leaves of the embryo; dicots have two, which often store food for the young plant

Hypocotyl

The part of the embryo between the radicle and the cotyledons; it will develop into the stem below the seed leaves

Epicotyl

The portion of the embryo above the cotyledons, which will develop into the shoot, including the stem and leaves

Radicle

The embryonic root; the first part of the seedling to emerge during germination, developing into the root system

Micropyle

A small opening in the seed coat through which water enters during germination

Pericarp

The part of a fruit formed from the ovary wall after fertilization; in monocots, this is fused with the seed coat

Seed Germination

The process by which a seed develops into a new plant, beginning with the emergence of the radicle and followed by the growth of the shoot

Microsporocyte

A diploid cell in the anther that undergoes meiosis to produce four haploid microspores, which develop into pollen grains (male gametophytes)

Pollen Grain

The male gametophyte of flowering plants, containing two sperm cells and a tube cell, responsible for fertilization of the ovule

Anther

The part of the stamen where microsporocytes are found and pollen grains are produced and released

Megasporocyte

A diploid cell in the ovule that undergoes meiosis to produce four haploid megaspores, only one of which survives to become the female gametophyte

Embryo Sac

The female gametophyte in flowering plants, typically consisting of seven cells (including the egg cell and two polar nuclei) formed from the surviving megaspore

Ovule

The structure within the ovary that contains the megasporocyte and develops into a seed after fertilization

Stigma

The sticky top part of the pistil that receives pollen during pollination

Pollination

The process of transferring pollen from the anther (male) to the stigma (female) of a flower, enabling fertilization

Double Fertilization

A unique process in flowering plants where one sperm fertilizes the egg to form a zygote, and the other fuses with polar nuclei to form the endosperm

Endosperm

The triploid (3n) tissue formed after double fertilization, which provides nourishment to the developing embryo within the seed

Monocot Seed

• Has one cotyledon (seed leaf);

• pericarp is fused with seed coat;

• most of the seed is endosperm, which serves as food for the embryo;

• endosperm is thick and rich in carbohydrates;

• during germination, the seed splits and the embryo grows out;

• the radicle gives rise to roots

Dicot Seed

• Has two cotyledons (seed leaves);

• cotyledons often store food for the embryo;

• embryo has a distinct hypocotyl, epicotyl, and radicle;

• the radicle and root emerge first during germination, followed by the hypocotyl standing erect and the epicotyl developing into the shoot

Monocot Cotyledon

Single cotyledon that absorbs nutrients from the endosperm for the embryo

Dicot Cotyledons

Two cotyledons that often store food and nourish the embryo

Monocot Endosperm

Prominent and serves as the main food reserve for the embryo

Dicot Endosperm

Usually absorbed by the cotyledons during seed development; cotyledons serve as the main food reserve

Monocot Germination

Radicle gives rise to roots; embryo grows out after seed splits

Dicot Germination

Radicle and root emerge/elongate first; hypocotyl stands erect, then epicotyl and shoot apex become visible

Allochory

Process of seed dispersal where various factors contribute to the final resting place of a plant's seed.

Anemochory

Seed dispersal by air or wind.

Hydrochory

Seed dispersal by water.

Zoochory

Seed dispersal by animals.

Endozoochory

Dispersal where seeds/fruits pass through the digestive system of animals before being released (e.g.

Myrmecochory

Seed dispersal by ants.

Ornithochory

Seed dispersal by birds.

Chiropterochory

Seed dispersal by bats.

Malacochory

Seed dispersal by molluscs or snails.

Anthropochory

Seed dispersal by humans