Flowering Plants

Obtaining Water and Nutrition

Flowering plants have two organ systems-the shoot system and the root system. The

shoot system- consists of the stem, leaves, buds, flowers and fruits. The

root system- consists of either a branching or a fibrous system of roots. Some plants grow over many years (perennial) while others grow in a year or a single season (annual).

Root system

The function of the root system is to anchor the plant to the surface and to absorb and transport water and minerals. The root system may also store substances or allow vegetative propagation.

Vegetative reproduction is the process where new plants arise without the production of seeds. It occurs in the specialised cells and tissues of roots, stems and leaves of some flowering plants.

Shoot System

The shoot system consists of the stem, leaves, flowers and fruits. The stem supports everything up and into positions where they can function effectively. The stems contain tube-like vascular bundles allowing the water and minerals to travel to the plant.

Reproduction

Sexual reproduction occurs in the flowers and fruits of the plant. Sexual reproduction is important as it produces offspring with different characteristics to the parent plants, allowing a better chance to survive in the changing environment. Sexual reproduction occurs when the flowers are pollinated and, when mature, form fruits that release seeds or attract animals that will disperse the seeds.

How They Obtain Water and Minerals

In the flowering plant, the cell membrane acts as a barrier for diffusion. This stops particles such as dissolved salts and sugar from getting through but allowing water in. Osmosis is the movement of water through a semipermeable membrane. During osmosis, water goes from a higher water concentration area to a lower water concentration area. The cytoplasm in root hair cells contains lots of dissolved substances, so the water in soil moves into the plant by osmosis.

Photosynthesis

Photosynthesis is the reaction used by plants to transform light energy into chemical energy. Photosynthesis is done by a chemical called chlorophyll, a green pigment in the chloroplasts of plant cells. Photosynthesis first occurs when the chlorophyll traps the light energy and then the sugars are made.

Respiration

Respiration is the opposite of photosynthesis. During the day, the oxygen released will be available for respiration and the carbon dioxide released from respiration will be available for photosynthesis. Respiration releases energy to run the metabolic process within a plant. This includes making leaves, flowers, fruit and seeds. Glucose formed by photosynthesis is moved by phloem cells to the leaves and cells within the plant. Some glucose is converted into parts of the plant’s membrane.

Mitosis

Mitosis is a type of cell division where one parent cell divides to produce two daughter cells with the same identical genetic instruction carried in their DNA. When the cell divides, these molecules condense into structures called chromosomes.

Meiosis- Sexual reproduction is dependent on the production of

Gametes- (sex cells) in a special type of cell division called meiosis.

Meiosis- is when the daughter cells contain only one member from each of the pairs of chromosomes of the original parent cell. A new organism is the result of union or

Fertilisation- of two gametes, which restores the full complement of chromosomes to the cells of the first cell of the new organism called the zygote.

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Asexual Reproduction results from mitosis and the offspring are the same as the parents. Asexual reproduction occurs in many unicellular organisms as well as many plants and simple animals. In plants, it is referred to as vegetative reproduction.