Table of Contents
What does each pollen grain grow?
Each pollen grain contains vegetative (non-reproductive) cells (only a single cell in most flowering plants but several in other seed plants) and a generative (reproductive) cell. In flowering plants the vegetative tube cell produces the pollen tube, and the generative cell divides to form the two sperm nuclei.
What happens to the pollen grain after pollination?
Only after pollination, when pollen has landed on the stigma of a suitable flower of the same species, can a chain of events happen that ends in the making of seeds. A pollen grain on the stigma grows a tiny tube, all the way down the style to the ovary. The ovary develops into a fruit to protect the seed.
What grows out of a pollen grain?
When a pollen grain lands on the stigma of a flower of the correct species , a pollen tube begins to grow. It grows through the style until it reaches an ovule inside the ovary. The nucleus of the pollen then passes along the pollen tube and fuses (joins) with the nucleus of the ovule.
What forms after a pollen grain reaches a flower?
When the pollen grain germinates on the stigma it creates a burrow called the pollen tube as it travels toward the ovary. When the sperm cell from the pollen grain reaches the ovary or ovule the sperm joins with the egg. This is called fertilization. The fertilized zygote will become a tiny new plant inside the seed.
What is germination of pollen grains?
During germination, the tube cell elongates into a pollen tube. In the flower, the pollen tube then grows towards the ovule where it discharges the sperm produced in the pollen grain for fertilization. The germinated pollen grain with its two sperm cells is the mature male microgametophyte of these plants.
How pollen grains are formed?
Development of pollen grains (male gametophytes) takes place in the anther. Pollen development begins when specialized cells (microsporocytes) differentiate in young anthers. There are generally hundreds or thousands of microsporocytes per anther and each passes through meiosis to produce four haploid microspores.
What happens after pollination and fertilization?
Step one: After pollen has landed on the stigma, it grows a pollen tube down through the style to the ovary. Step two: The nucleus of the pollen grain travels down the pollen tube and fertilises the nucleus in the ovule. Step three: The fertilised ovule develops into a seed.
What happens after fertilization in plants?
After fertilization occurs, each ovule develops into a seed. Each seed contains a tiny, undeveloped plant called an embryo. The ovary surrounding the ovules develops into a fruit that contains one or more seeds.
How does pollen germinate after pollination?
4.7 Pollination and seed growth Pollen is required for pollen germination followed by fertilization and seed formation. One sperm fertilizes the egg within the ovule and the other one fuses to the secondary nucleus, and therefore a double fertilization occurs.
What is the process of pollen germination?
How pollen grain and embryo sac are formed?
Many microspore mother cells occur in the pollen sacs; each undergoes meiosis to produce four microspores. Megaspores develop into embryo sacs, microspores into pollen grains. The pollen grain germinates, forming a pollen tube that delivers the sperm to the egg in the ovule during fertilization.
What happens to pollen after pollination?
Only after pollination, when pollen has landed on the stigma of a suitable flower of the same species, can a chain of events happen that ends in the making of seeds. A pollen grain on the stigma grows a tiny tube, all the way down the style to the ovary. The ovary develops into a fruit to protect the seed. Click to see full answer.
How do pollen grains germinate in plants?
Once a pollen grain settles on a compatible pistil, it may germinate in response to a sugary fluid secreted by the mature stigma. Lipids at the surface of the stigma may also stimulate pollen tube growth for compatible pollen.
What happens when pollen grains land on the stigma?
When pollen grains land on the stigma, they stick to it and begin to germinate. A microscopic tube sprouts from each pollen grain and starts to grow into the stigma. It then grows down through a stalk, called the style, towards the eggs in the ovules below. what is the function of the stigma?
How does pollination start the reproduction process?
Whether carried by insects, birds, animals or wind, pollen makes its way from the male flowers to the female flowers to begin the reproduction process. But this movement is only the beginning. After pollination there is a flurry of activity that leads to the production of a new plant. Video of the Day