PLANTS PLANT GROUPS 1. Plant groups Plants have roots, a stem and leaves. The roots are in the soil. Water and other substances are absorbed from the soil through the roots. The stem supports the leaves. Water and nutrients are transported from the roots to the leaves inside the stem. The leaves breathe and make the plant´s food.
2. Flowering plants Flowering plants are the biggest group of plants. Gymnosperms have small flowers, but no fruit. Their seeds are all together in cones. Almost all gymnosperms are trees , such as pine trees. •
Angiosperms have flowers and fruit. Chesnut trees and some grasses are angiosperms. •
Plant parts
Fern
3. Non-flowering plants Non-flowering plants are the smallest group of plants. They need shade and moisture. • Mosses are small plants which live on rocks, trees and the ground. • Ferns are larger than mosses. They have thick, underground stems and big leaves.
PLANT NUTRITION 1. Respiration Like all living things, plants breathe. They take oxygen from the air, and release carbon dioxide. This exchange of gases is called respiration. It takes place in leaves continually, day and night.
2. Plant nutrition Plants obtain food in a different way from animals. Plants are autotrophs: they make their own food. To make food, plants need sunlight, carbon dioxide, water and minerals from the soil.
3. Water and minerals Water and minerals are important for plant nutrition. In the soil minerals dissolve in water. Plants absorb this water through their roots. These nutrients, called raw sap, travel up the stem to the leaves.
4. Photosynthesis Photosynthesis enables plants to make food
from sunlight , carbon dioxide, water and minerals. Photosynthesis takes place in the leaves. In the leaves , raw sap mixes with carbon dioxide and becomes elaborated sap. This is the plant´s food. Sunlight is essential for photosynthesis, so it only takes place during the day. During photosynthesis, plants release oxygen.