Asexual vs Sexual Reproduction

• Reproduction is the process where offspring are produced from parents.

Asexual vs. Sexual Reproduction

• Asexual reproduction involves only one parent organism.
• Offspring from asexual reproduction are identical to the parent, known as clones.
• Variations are rarely observed in asexual reproduction.
• Sexual reproduction involves two parent organisms or gametes
• Offspring from sexual reproduction share similarities with parents but are not identical.
• Variations are commonly observed in sexual reproduction.

Fragmentation

• Algae, upon maturing, can fragment or divide into multiple parts.
• Each fragment has the ability to grow into a new individual
• Spirogyra is an example of this type of reproduction.

Budding

• Budding serves as an asexual method of reproduction.
• Under favorable conditions, an outgrowth, or bud, emerges on the parent organism's body.
• The bud gradually grows and eventually detaches from the parent organism.
• In yeast, the bud may remain attached, forming chains of buds.

Vegetative Propagation

• Vegetative propagation occurs using vegetative parts such as leaves, stems, and roots.

Natural Vegetative Propagation

• Leaves, such as notches in bryophyllum, give rise to new buds.
• Roots, such as sweet potato, carrot, and radish, can facilitate propagation.
• Underground stems, such as the tuber of a potato, can grow new buds from each eye (scar).
• Bulbs, such as onions, possess short and upright structures.
• Corms, exemplified by colocasia, feature short and upright structures with concentrically arranged nodes.
• Rhizomes, horizontal stems like ginger, are another type of stem to propagate.

Sub-Aerial Stem Propagation

• Runners spread horizontally over the ground, examples include grass and oxalis.
• Stolons are short branches that grow upwards, bend down, touch the ground, and form roots, such as mint and strawberry.
• Suckers grow underground, then grow upwards obliquely, such as bananas.

Artificial Propagation

• Cutting involves cutting a small stem from a parent plant and burying the lower part in the soil, where it develops roots, examples include rose, grapes, and sugarcane.
• Grafting involves joining a shoot part (scion) from one plant with desired qualities to a root part (stock) of another plant for support and nutrients, seen in apple, mango, and rose.
• Layering involves bending a mature branch of a parent plant, covering it with soil while keeping the tip above ground, allowing roots to develop from the branch, commonly used in plants with long and slender branches like jasmine.

Spore Formation

• Fungi like bread mold reproduce asexually by spore formation.
• Fungi develop bulb-like structures called sporangia during unfavourable conditions.
• With the onset of favorable conditions the sporangium bursts, thus releasing spores which germinate to form new plants.

Flower Diagram

• Key parts of a flower include the pistil (stigma, style, and ovary), stamen (anther and filament), petals (corolla), sepals (calyx), receptacle, and pedicel.

Flower Types

• Complete flowers contain all four whorls or parts: pistil, stamen, calyx, and corolla (examples include pea, mustard, hibiscus, and gulmohar).
• Incomplete flowers lack one or more of these four whorls (examples include date palm, mulberry, and maize).
• Unisexual flowers contain either a pistil or a stamen, permitting only cross-pollination and thus requiring another plant for reproduction (examples include papaya and watermelon).
• Bisexual flowers contain both pistil and stamen, capable of both self and cross-pollination (examples include hibiscus and rose).

Pollination

• Pollination involves the transfer of pollen grains from the anther of a stamen to the stigma of a pistil.
• Self-pollination transfers pollen from the anther to the stigma within the same flower.
• Self-pollination occurs exclusively in bisexual flowers and does not require pollinating agents.
• Cross-pollination involves the transfer of pollen from the anther of one flower to the stigma of another flower.
• Cross-pollination occurs in unisexual and bisexual flowers and requires pollinating agents.

Agents of Pollination

• Biotic agents of pollination include bees, birds, and mammals.
• Abiotic agents of pollination include wind and water.

Pollination Types

• Anemophily is pollination by wind, with colourless and odourless flowers and light, non-sticky pollen, such as in grasses.
• Hydrophily is pollination by water, with colourless and odourless flowers and light, ribbon-like pollen, such as in Hydrilla and Vallisneria.
• Entomophily is pollination by insects, with colourful and fragrant flowers and sticky pollen, such as in rose and hibiscus.
• Zoophily is pollination by animals, with flowers with sticky pollen, such as in canna and salvia.