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It is the formation of new individuals from the cell(s) of a single parent.
It is most common in plants but it can find place even in animals
It does not involve fusion of gametesOffsping become genetically identical
ASEXUAL REPRODUCTION
Two individuals produce offspring that have genetic characteristics from both parents. Sexual reproduction introduces new gene combinations
It involves the union or fusion of a male and a female gamete
This is how humans and most animals reproduce
SEXUAL REPRODUCTION
The flower is the reproductive organ of a plant
It’s reproductive portions are the stamen, consisting of the filament and the anther which has pollen grains that contain male gametes
The stigma, style and ovary instead make the female part of the plant which is called carpel
The ovary has ovules which contain the female gametes
Pollination and fertilization are the two main events for reproduction
Pollination is the transfer of pollen from the anther to the stigma of the pistil
When pollen from a plant's stamen is transferred to that same plant's stigma it is called self-pollination
When instead it is transferred to a different plant's stigma, it is called cross-pollination, it produces stronger plants but they must be of the same species
FROM POLLINATION...
The stigma, because of it’s stickiness, receives pollen grains in different ways
Pollen trapped by the stigma pollinates to produce a long tube that travels down the style and enters the ovaries
The pollen tube contains the male gamete which fuses with the female gamete in the ovule, this fusion process is called fertilization
The ovule, when fertilized, transforms in the seed, after they are formed the ovary matures to produce fruit
New plants grow from the seeds and this is the process by which plants propagate themselves
TO FERTILIZATION
Plants rely on animals or wind to pollinate them. When animals such as bees, pollinate plant accidentally because they are
actually at the plant to get food from the sticky pollen or a sweet nectar made at the base of the petals. While feeding, the animals accidentally rub against the stamens and get pollen stuck all over themselves. When they move to another flower to feed, some of the pollen can rub off onto this new plant's stigma.
Plants that are pollinated by animals often are brightly colored and have a strong smell to attract the animal pollinators.
Another way plants are pollinated is by the wind. The wind picks up pollen from one plant and blows it onto another.
Plants that are pollinated by wind often have long stamens and pistils. Since they do not need to attract animal pollinators, they can be dully colored, unscented, and with small or no petals since no insect needs to land on them.
Is some cases humans hand also occur..(but we will see and example later)
DIFFERENT WAYS FOR POLLINATION TO OCCUR
POLLENGrain of pollen: microscopic
part produced by the anther that serves as the male agent of fertilization in flowering plants.
Thickening of cellulose: fibrous thickening.
Exine: outer layer of a pollen grain.
Intine: inner layer of a pollen grain.
Nucleoli: control centers of cellular activity.
Pore: small hole.
WE ARE FINISHED BUT LET ME TELL YOU
AN INTERESTING EXAMPLE ABOUT HOW
HUMANS IN SOME CASES HELP
POLLINATION
The world's most expensive spice, vanilla is an orchid In its native Central America, the vanilla flower is
pollinated by a small bee the morning the flower opens To ensure seed pods are formed in cultivation, humans
must be the pollinator, manually transferring pollen to the stigma of the flower
As vanilla flowers last only one day, the pollination must occur in the morning after the flower first opens
Seed pods formed by pollinating a flower with its own pollen will not contain seeds that will germinate
VANILLA (you do not have to copy this guys) ;)
OF WHAT ARE THE MALE AND FEMALE PARTS OF A PLANT COMPOSED?
WHAT ARE THE WAYS FOR POLLINATION TO OCCUR?
HOW IS THE SEED FORMED?
QUESTIONS(yuppie!)
NOW I REALLY AM DONE!THANK YOU FOR YOU ATTENTION 3B AND I HOPE YOU HAVE LEARNED SOMETHING (I will leave you with a song ) http://www.mbgnet.net/bioplants/pollensong.html
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