Definitions [9]
Define
Photosynthesis
Photosynthesis: The process by which plant leaf prepares or synthesizes food from water and carbon dioxide in the presence of chlorophyll and sunlight is called photosynthesis.
Define venation.
Venation: Arrangement of a pattern of veins in a lamina is called venation.
Define
Tranpiration
Tranpiration: This is the process by which there is a loss of water in the form of vapour by evaporation from the surface of leaves. It has a cooling effect, it causes the suction force to make roots absorb more water with mineral ions.
A modified, compressed reproductive shoot of angiosperms bearing sepals, petals, stamens, and carpels, meant for sexual reproduction, is called a flower.
A circular arrangement of floral organs at the same level on the thalamus is called a whorl.
The swollen terminal part of the pedicel on which all floral whorls are arranged is called the thalamus or receptacle.
When calyx and corolla are not differentiated, the floral envelope is called the perianth.
Individual members of the perianth are called tepals.
The pattern of ovule arrangement in the ovary is called placentation.
Key Points
- Flower: A modified shoot and the reproductive unit of angiosperms.
- Structure: Consists of four whorls—calyx, corolla (accessory), androecium, and gynoecium (reproductive).
- Types by sex: Flowers may be unisexual (male/female) or bisexual (both present).
- Symmetry: Actinomorphic (radial), zygomorphic (bilateral), or asymmetric.
- Based on floral parts: Flowers can be trimerous, tetramerous, or pentamerous depending on the number of parts.
- Position of ovary: Hypogynous (superior), perigynous (half inferior), epigynous (inferior).
