Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
A seed is a mature ovule that contains an embryo (the baby plant) and stored food, protected by a seed coat.
The Seed Coat (Testa) is the hard outer covering that protects the internal parts of the seed from damage and drying out.
The Micropyle is a tiny pore in the seed coat that allows water () and air () to enter the seed during germination.
The Hilum is a scar on the seed coat where the seed was originally attached to the fruit wall.
The Embryo is the most important part of the seed, consisting of the Radicle (future root) and the Plumule (future shoot/leaves).
Cotyledons are seed leaves that store food for the growing embryo. Plants with one cotyledon are called Monocots (e.g., maize, rice), and those with two are Dicots (e.g., grams, peas, beans).
Germination is the process by which a seed grows into a seedling. It requires three essential factors: Water (), Oxygen (), and a suitable temperature (warmth).
📐Formulae
💡Examples
Problem 1:
Identify the primary function of the Radicle during the early stages of seed germination.
Solution:
The Radicle develops into the Root System.
Explanation:
During germination, the Radicle is the first part of the embryo to emerge. It grows downwards into the soil to absorb water () and minerals, providing stability to the seedling.
Problem 2:
What happens to the Cotyledons of a bean seed after the first green leaves appear?
Solution:
The Cotyledons shrink and eventually fall off.
Explanation:
The Cotyledons store food for the embryo. Once the Plumule grows into green leaves, the plant begins making its own food through photosynthesis (), making the stored food in the cotyledons unnecessary.
Problem 3:
A dry seed is kept in an airtight container at room temperature. Will it germinate?
Solution:
No, it will not germinate.
Explanation:
For germination, a seed requires moisture () to soften the seed coat and activate enzymes, and oxygen () for respiration. An airtight container lacks sufficient oxygen, and a 'dry' seed lacks the necessary water.