Monday, September 6, 2010

I would like to acknowledge the following websites for their images/information which I refered to when I wrote this blog:

en.wikipedia.org/wiki/Asexual_reproduction
users.rcn.com/jkimball.ma.../A/AsexualReproduction.html
kentsimmons.uwinnipeg.ca/16cm05/16labman05/lb4pg6.htm
www.buzzle.com/articles/asexual-reproduction-in-plants.html
en.wikipedia.org/wiki/Vegetative_reproduction
www.answers.com/topic/vegetative-propagation
plantphys.info/plants_human/vegprop/vegpropn.shtml
www.bpi.da.gov.ph/Services/ppropagation.htm
wiki.answers.com/Q/Artificial_propagation_methods
www.buzzle.com/articles/asexual-reproduction-in-plants.html
biology.suite101.com/article.cfm/asexual-reproduction-in-plants


planting,
4:36 AM



Now we will end off with a short quiz.
Let's see how many questions you manage to get them correct!

1. The offspring from asexual reproduction in plants are likely to be
A be more resistant than their parent to disease
B develop into a new variety
C grow bigger than their parent
D have the same flower colour as their parent

2. Grafting is the method used to increase the numbers of a particular variety of plant. The figure below shows how a stem cutting from a variety of commercially important fruit tree, A, may be grafted in to roots of a variety of no particular value, B.
(a) State the type of reproduction shown by this process.

New trees will eventually bear fruit.

(b) Explain which if the two varieties will be responsible for the characteristics of the fruit produced.

(c) Suggest three ways of ensuring that the graft in the figure is successful.

3. With reference to a named plant, explain the commercial advantages of asexual reproduction.
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Answers:

1) D
There is no genetic variety for offsprings from asexual reproduction. They should carry flowers of the same colour.
Without genetic variety, asexual reproduction produces clones. Therefore, whatever the parent plant is capable or incapable of handling, so too the offspring.

2)
(a) Artificial vegetative propagation.
(b) Variety A;
The shoot system of the new trees are produced from the buds of A. The flowers and fruits that will develop later will also be an offshoot of the same variety.
(c) 1. The soil must be watered and aerated.
2. The two cut ends must be held in position properly. This can be achieved by using waterproof tape.
3. It is very important that the exposed cambia of A and B be in direct contact with each other. This is to ensure that they fuse.

3) The potato is an underground stem classified as a tuber. The potato plant is grown commercially by vegetative propagation. The 'eye' on the potato grows to produce new shoots which will eventually grow as new plants. This method of propagation allows new plants to be grown in a relatively shorter period of time, as opposed to being grown from seeds. The new plants also mature faster. A harvest of potatoes grown this way will produce genetically identical plants, a good batch of similar potatoes.

Asexual reproduction includes vegetative propagation, fission, budding, fragmentation, sporulation, parthogenesis and cloning. Parthenogenesis is the development of female gamete to produce offspring in the absence of fertilisation. In honeybees, unfertilised female gametes develop into male (drone) while fertilised eggs develop into female bees (worker/queen).
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This marks the end of this learning website!
I hope this website helped you to know more about asexual reproduction in plants!
Thank you and goodbye!


planting,
4:18 AM



Do you know that asexual reproduction actually has some useful applications?

Horticulture/Agriculture

Micropropagation

Manufacture

Pot plants and ornamental plants

Use of culture techniques

Plant Chemicals

Crop plants like sugar beet and potato

Result is a large quantity of genetically identical individual clones

E.g. skikonin is a dye used in silk industry and for treatment of burns

In plants which are difficult to propagate

-

For food flavours, perfumes and insecticides

Overcomes problems of seasonality

-

-


planting,
4:14 AM



What is Artificial Propagation?

It is a form of vegetative propagation.
It produces genetically identical plants from parent plants without seeds.
It starts a new plant from part of existing old plant.

Fig 5: Cutting

Fig 6: Grafting

Portion of root/shoot cut from parent plant

Fruits and ornamental plants which are difficult to grow from seeds

Root end treated with hormone to promote growth

The cut plant (scion) is attached to host (stock)

Root placed in moist soil/water until adventitious roots appear

Both cambiums fuse, scion is able to grow


> Fig 5
> Fig 6
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Do you know?
The stock is grown from seeds, but has its shoots cut away. The type of stock will affect the final size of the plant and its maturity period!


planting,
4:06 AM



Flowering plants have either male and/or female parts, or it could reproduce asexually.
There are two main methods of asexual reproduction: vegetative reproduction and artificial propagation.

Vegetative Reproduction
This involves the production of new plants from a part of the old, parent plant.
It involves storage organs such as bulbs, corms, tubers and rhizomes.
They enable plants to grow year after year (perennating organs).
They also serve as a food source for man.

Storage organ

Examples/Food

Fig 1: Tuber (underground stem)

Potato/Starch, vitamin C, water

Fig 2: Rhizome (underground stem)

Ginger/Starch

Fig 3: Bulb (underground shoot)

Onion/Glucose, water (in leaves)

Fig 4: Corm (underground shoot)

Water chestnut/Glucose, Water (in stems)

> Fig 1
> Fig 2
> Fig 3
> Fig 4

Is vegetative reproduction beneficial after all? Does it carry more pros than cons?
Let's investigate!

Advantages

Disadvantages

Identical daughter plants within a short period of time

Identical daughter plants lack in genetic variation

Daughter plants can be selected for desirable characteristics

Characteristics are similar to parents. If environment changes and parents are not able to adapt, daughter plants will also not adapt

Food supply not a problem as daughter plants dependent on parent plant

Competition for space, and food, because of proximity of plants

Not dependent on pollinators for reproduction

-

Conditions for reproduction are favourable

-

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Do you know?
A plantation of bamboo was cultivated as a crop plant. When one plant starts to flower, all the others will do so as well. In Bamboo plants, flowering marks the end of its cycle. Hence the entire plantation of bamboo was lost!


planting,
3:12 AM



Hello everyone!

Do you know what is asexual reproduction?
In this post, we shall explore the differences between sexual reproduction and asexual reproduction.

We will first start off with a video.
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In asexual reproduction, the offsprings produced are identical.
In sexual reproduction, the new individuals differ genetically from their parents.

Task #2: Group these following characteristics into a table with two categories: 1) Sexual Reproduction; 2) Asexual Reproduction.

1) Cell division, binary fission, spores, vegetative reproduction, artificial propagation
2) No zygote
3) Rate rapid under favorable environments
4) Takes a long time
5) Male and female sex cells (haploid gametes)
6) No sex cells
7) Population increases slowly
8) Population increases rapidly
9) Plants and more complex organisms
10) Sexual reproductive organs in plants and animals
11) Two parents
12) Undergoes mitosis
13) Fertilisation forms a diploid zygote
14) Offspring genetically different from both parents
15) Undergoes meiosis
16) Offspring genetically identical to parent Plants and simple organisms
17) Male and female sex cells (haploid gametes)
18) One Parent
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Do you know?
Asexual reproduction produces clones. It is common among simplest organisms. It produces offsprings without the need of gametes or searching for a mate!

Suggested Answer Key to Task #2:

Asexual

Sexual

Cell division, binary fission, spores, vegetative reproduction, artificial propagation

Sexual reproductive organs in plants and animals

One parent

Two parents

No sex cells

Male and female sex cells (haploid gametes)

No zygote

Fertilisation forms a diploid zygote

Undergoes mitosis

Undergoes meiosis

Offspring genetically identical to parent

Offspring genetically different from both parents

Rate rapid under favourable environment

Takes a long time

Population increases rapidly

Population increases slowly

Plants and simple organisms

Plants and more complex organisms


planting,
1:59 AM



Hi Miss Ting!

This is an ACE website I have done on the topic 'Asexual Reproduction in Plants'.
This website includes:
1) Information posts;
2) Photos, Pictures, Videos;
3) Quizzes

Hope you will enjoy your exploration here!


planting,
1:56 AM


About.

This Blog is done by
Chen Shenghui, 4B103.

Interesting Factos.

1)Asexual reproduction in plants is a form of agamogenesis which refers to reproduction without the fusion of gametes.

2)Some species alternate between the sexual and asexual strategies, an ability known as heterogamy, depending on conditions.

Special Thanks.

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