Plant Hormones and Seed Dispersal

Sepals = Enclose and protect the flower before it opens and will sometimes close over the flower at night Petals = Most obvious part of the flower, large, variously shaped and bright to attract pollinators, produce scent to attract insects Stamens = Male part of the plant and consists of anther and filament Carpel = Female part of the plant and consists of stigma, style, and ovary

Anther = Produces pollen which forms male gametes Stigma = Catches pollen Style = Connects the stigma to the ovary and holds it in a suitable position to collect the pollen Ovary = Has one or more ovules which contain the embryo sac

Stamens = Male part of the plant Carpel = Female part of the plant Sepals = No specific gender Petals = No specific gender

Artificial Propagation Cuttings = Part of the shoot is removed and placed in soil or water to form roots Layering = A cut shoot is pegged into soil and develops into a new plant Grafting = A shoot twig (scion) is removed and taped into the root stock Micropropagation = Individual cells i.e., stem, root, or leaf, can be removed from a plant and then grown in tissue culture

Artificial Propagation Cuttings = Geranium Layering = Blackberry Grafting = Apples Micropropagation = Bananas

Plantlet = When it touches the ground, roots grow into the ground Runner = Withers when the new plant becomes independent Scion = Part of the plant that is removed and taped into the root stock in grafting Adventitious roots = Grow after one year in layering and then are cut off from parent plant

Animal Dispersal = Tomato seeds and apple seeds Wind Dispersal = Sycamore parachutes and dandelion parachutes Self-dispersal = Gorse Water-dispersal = Yellow water lily

Stem Tubers = Potatoes Root Tubers = Sweet potatoes Bulbs = Daffodils Plantlets = Strawberry plants

Radicle Emergence = The root starts to grow downwards from the seed Plumule Growth = The shoot starts to grow upwards from the seed Leaf Break = The leaves break the surface and the seedling begins to photosynthesize Weight Gain = The plant starts to gain weight

Soaking the seeds in chemicals = To wash out inhibitors Applying plant hormones such as gibberellins = To promote germination Soaking the Testa = To allow water to enter the seed Cracking the Testa = To break the seed coat

Egg sac = Contains the egg cell and two polar nuclei which will form the endosperm Receptacle = Thickened part of the pedicel from which the flower parts grow Nectary = Located at the base of the petals and produces nectar Pollen grain = Matures, forming a tough layer on the outside called the exine

Self-pollination = Occurs when the anther and stigma are on the same plant, leading to less variation Cross-pollination = Occurs when the anthers and stigma are on different plants, promoting genetic diversity Insect Pollination = Bees visit the flower to collect nectar and pollen to feed their young, becoming covered in pollen Wind Pollination = Plants like wheat and barley produce light pollen which drifts away on the breeze

Fertilization = The fusion of the male gamete with the female gamete to form a diploid zygote Pollen tube = Grows down the style to the ovule, guided by chemotropism and the tube nucleus Generative nucleus = Divides by mitosis to form two sperm nuclei as the pollen tube grows down Double fertilization = One male gamete fuses with the egg cell, while the other fuses with the two polar nuclei to form the endosperm

Embryo = Part of the seed that will develop into the new plant Testa = A tough and hard seed coat which protects the seed before germination Radicle = First part of the new plant to emerge from the seed, develops into the root Cotyledons = Seed leaves which contain food reserves used in the early stage of germination