Note: All such structures capable of forming new plants are called vegetative propagules.
Definitions [6]
Life Span: The period from birth to the natural death of an organism represents its life span. It is possible to compute it by utilising the entity's average life span. It varies based on the individual and species and can last anywhere from a few minutes to several years. A specific entity's life span is determined by various genetic factors.
Definition: Lifespan
Lifespan is the duration or period from birth to the natural death of an organism.
Definition: Reproduction
Reproduction is the process of formation of new individuals by sexual or asexual means, which can repeat the process in their own turn.
or
Formation of new organism of same species by earlier existing organism is called as reproduction.
or
Reproduction is a biological process that results in the formation of new individuals of the same kind, though usually with slight genetic, structural and physiological variations.
Definition: Natural Vegetative Propagation
The process in which a new plant develops from a vegetative part (stem, root, or leaf) of the parent plant under suitable conditions is called natural vegetative propagation.
Definition: Artificial Vegetative Propagation
The method of plant reproduction in which a part of the mother plant is detached and grown independently to produce a new plant with identical characters is called artificial vegetative propagation.
Define perisperm.
A perisperm is a nucellus that remains after fertilisation.
Key Points
Key Points: Reproduction
- Meaning - Reproduction is the production of young ones similar to their parents. It is an essential biological process for the continuation of the species and continuity of life.
- Lifespan = period from birth to natural death; ranges from 1 day (Mayfly) to 3,000–4,000 years (Sequoia).
- Two Types - All methods of reproduction fall into two categories: Asexual Reproduction and Sexual Reproduction.
- Single-celled organisms (Amoeba, Bacteria) do not undergo natural death — they divide by binary fission.
- Four life stages: Juvenile → Reproductive → Senescent → Death.
- In plants, the reproductive phase begins at flowering.
- Monocarpic plants flower once; Polycarpic plants flower every season.
- Asexual reproduction = one parent, clones produced, faster.
- Sexual reproduction = two parents, gametes, zygote formed, genetic variation.
- The three phases of sexual reproduction: Pre-fertilisation → Fertilisation → Post-fertilisation.
Key Points: Natural Vegetative Propagation
| Part Involved | Structure | Key Feature | Example |
|---|---|---|---|
| Underground stem | Rhizome / Tuber / Bulb / Corm | Modified stem with buds | Ginger, Potato, Onion, Colocasia |
| Sub-aerial stem | Runner / Offset / Sucker / Stolon | Creeping or branching stem | Doob grass, Water hyacinth, Mint, Strawberry |
| Root | Tuberous / Adventitious roots | Roots bear buds | Sweet potato, Dahlia |
| Leaf | Foliar buds | Buds on leaf margin or surface | Bryophyllum, Begonia |
| Special structure | Bulbil | Modified bud or flower | Agave, Dioscorea |
