Asexual Reproduction IGCSE Biology

Asexual reproduction Asexual reproduction involves NO fertilisation between male and female gametes. Offspring are genetically identical to their “parents”

Can you think of some examples of organisms that asexually reproduce?

What is a clone? A clone is genetically identical to its “parent”

How do plants reproduce asexually? Tubers eg potato – grows shoots Runners eg strawberries bulbs eg tulips

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 This means that they are able to adapt to their surroundings and evolve. Offspring have no variation Offspring are genetically identical to one another. This is an advantage when the parent is well adapted to its habitat. Does not need a partner – saves time and energy to attract a mate. Very quick – bacteria can produce an offspring in about 20 minutes

Asexual reproduction Also known as vegetative propagation 3 methods of (natural) vegetative propagation -tubers -bulbs -runners

Tubers 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

Let´s plant a tuber! Take a small pot/cup and half fill with compost Take seed potato and place into your cup Cover the potato with more compost until the cup is 2/3 full Water your potato and cover with cling film Don´t forget to put your name, the date and the type of plant on your cup!

Bulbs E.g. daffodils, lilies

Let´s plant a bulb! Take a small pot/cup and half fill with compost Take a baby onion and place into your cup Cover the onion with more compost until the cup is 2/3 full Water your onion and cover with cling film Don´t forget to put your name, the date and the type of plant on your cup!

Runners 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)

Let´s plant out a runner! A spider plant is a good example of a plant that produces runners The end of the runner can be ‘pegged down’ into a small pot of compost using wire When the roots are established, the runner is cut close to the new plant and the wire removed

Artificial Propagation 2 methods used to cultivate plants asexually -taking cuttings -grafting

Cutting They can be placed in moist soil or water (and sometimes dipped in rooting powder). Cuttings are small pieces of stem with some leaves attached, the new plant grows from this.

Let´s take a cutting! Take a small pot/cup and fill 2/3 with compost Take your cutting and dip the end in rooting powder Gently plant into your cup Water your cutting and cover with cling film Don´t forget to put your name, the date and the type of plant on your cup!

Grafting 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

Commercial aspects 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.