MADE BY CHITRAN MANDAL 05X

Sexual Reproduction

Asexual Reproduction

Definition •Involves sex cells and fertilisation

•Does not involve sex cells and fertilisation

•Only one parent plant

Advantages/Disadvantages

•Offspring are not genetically identical to one another

•There is variation in the offspring

•Offspring have no variation

•Offspring are genetically identical to one another

Tubers are underground food stores which stores food over the winter and provides a new plant with food until it can make its own.

Food made by the new plant is sent to make new tubers. Thereby reproducing itself.

Examples: potato, artichoke, yam, cassava, water chestnut, arrowroot

Taro- Japanese potato

Also known as vegetative propagation

3 methods of vegetative propagtaion-tubers-bulbs-runners

E.g. daffodils, lilies

Runners are side shoots which grow out from the parent plant.

Buds form at points along the runner and eventually these buds form roots and grow into new plants.

Examples: spider plant (Anthericum), strawberry (Fragaria x ananassa)

They can be placed in moistsoil or water (and sometimesdipped in rootingpowder).

Cuttings are small pieces of stem with some leaves attached, the new plant grows from this.

A cut stem of one plant (with good flower or fruit growth) (the graft) is taken and firmly attached to the rootstock of another plant (which has a strong, established root system) (the stock).

Examples- roses, fruit trees

Artificial propagation has allowed us to adapt and improve plants for our own use.

Some of the benefits include:•Quick production of large numbers of genetically identical plants.•Specific varieties, desired features or consistent quality can be produced especially in fruit, flowers.

Fission the separation of the parent into two or more

offspring of equal size Budding

new individuals split off from existing ones Fragmentation and regeneration

the breaking of the body into several pieces, some or all of which develop into new adults

Par thenogenesis Development of unfertilized eggs

Parent divides into halves after nucleus replicates

No parent remains daughter cells grow to normal size

Occurs in , , and

2 equal

2

bacteria protozoa algae

Parent organism divides into halves

Daughter cell forms from outgrowth or off parent

Buds may or remain attached and form a

2 unequal

bud

break offcolony

Ability to back missing parts The more the organism, the

it is to regenerate Occurs in simple organisms such as

and

grow

complexharder

starfish flat worm

In this form, the body of the parent breaks into distinct pieces, each of

which can produce an of fspring.

Pieces of coral broken off in storms

can grow into new colonies.

A new starfish can grow from

one detached arm.

of a body of a multicellular organism gives rise to a organism

Common in - using stems, leaves, or roots

Can occur or

Piece new

plants

naturally artificially

Bulb-

Corm-

Tuber-

Runner-

Rhizome-

Short underground stem with stored food & fleshy leaves Ex. Onion, tulip

Short underground stem with stored food Ex. Water chestnut

Enlarged underground stem Ex. potato

(stolon) horizontal stem with buds along ground’s surface Ex. strawberry

Underground horizontal stem

Ex. ginger

Tuber

Bulb

CormRhizome

Runner

Cutting- use of plant to reproduce (Ex. )

Layering- stem is over and covered with will root and form plant (Ex. )

Graf ting- stem or bud of one plant is to another plant

(Ex. )

partSpider plant

bent soilnew raspberry

joined

Seedless fruit treepermanently

Layering Grafting

scion

stock