Attention Deficit Disorder Prosthetic Memory Program

Pollination

ADDPMP132
Pollination - © Attention Deficit Disorder Prosthetic Memory Program

Pollination is the transfer of pollen from a male part of a plant to a female part of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind.[1] Pollinating agents are animals such as insects, birds, and bats; water; wind; and even plants themselves, when self-pollination occurs within a closed flower. Pollination often occurs within a species. When pollination occurs between species it can produce hybrid offspring in nature and in plant breeding work.

In angiosperms, after the pollen grain (gametophyte) has landed on the stigma, where it germinates and develops a pollen tube which grows down the style until it reaches an ovary. Its two gametes travel down the tube to where the gametophyte(s) containing the female gametes are held within the carpel. After entering an ovum cell through the micropyle, one male nucleus fuses with the polar bodies to produce the endosperm tissues, while the other fuses with the ovule to produce the embryo. Hence the term: “double fertilization”. This process would result in the production of a seed made of both nutritious tissues and embryo.

In gymnosperms, the ovule is not contained in a carpel, but exposed on the surface of a dedicated support organ, such as the scale of a cone, so that the penetration of carpel tissue is unnecessary. Details of the process vary according to the division of gymnosperms in question. Two main modes of fertilization are found in gymnosperms. Cycads and Ginkgo have motile sperm that swim directly to the egg inside the ovule, whereas conifers and gnetophytes have sperm that are unable to swim but are conveyed to the egg along a pollen tube.

The study of pollination spans many disciplines, such as botany, horticulture, entomology, and ecology. The pollination process as an interaction between flower and pollen vector was first addressed in the 18th century by Christian Konrad Sprengel. It is important in horticulture and agriculture, because fruiting is dependent on fertilization: the result of pollination. The study of pollination by insects is known as anthecology.

Water Overdose - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP575
Water Overdose
Fluid Dynamics - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP296
Fluid Dynamics
Winona Ryder Shoplifting - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP530
Winona Ryder Shoplifting
Bananadine - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP535
Bananadine
Zodiak Free Arts Lab - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP145
Zodiak Free Arts Lab
Trepanation - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP197
Trepanation
Maki Asakawa - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP275
Maki Asakawa
Gates Of Hell - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP428
Gates Of Hell
Vanishing Point - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP418
Vanishing Point
Photo Finish - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP279
Photo Finish
Chandra Oppenheim - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP245
Chandra Oppenheim
In My Room : Teenagers in Their Bedrooms - © Attention Deficit Disorder Prosthetic Memory Program
ADDPMP164
In My Room : Teenagers in Their Bedrooms

You are using an outdated browser.
Please upgrade your browser to improve your experience.