Pollen tube growth is one of the most fascinating—and essential—phenomena in the life cycle of flowering plants. After a compatible interaction between pollen grains and the stigma surface, the pollen germinates and forms the pollen tube, which grows through the stigma, style, and transmitting tract to deliver the sperm cells to the ovule."
2) Although pollens of many species germinate in simple aqueous media, stigmas do not provide satisfactory sites for the germination of most foreign pollen... Stigmas not only provide the proper conditions for the germination of pollen from their particular species, they actively inhibit the germination of pollen of many unrelated species.
Answer:
Arteries are blood vessels that carry oxygenated blood away from the heart. Their walls are composed of three layers called the tunica intima, tunica media, and the tunica adventitia, which all have different cellular structures and compositions.
Explanation:
Similarly, organs are defined are being a collection of tissues, which are joined in a structural unit to serve a common function.An artery is made up of several types of tissues including: Elastic tissue - this evens out the pressure changes in the vessel when the heart ventricles contract, by stretching and recoiling ...
1. The binding of an inhibitor can stop a substrate from entering the enzyme's active site and/or hinder the enzyme from catalyzing its reaction. Inhibitor binding is either reversible or irreversible. Irreversible inhibitors usually react with the enzyme and change it chemically (e.g. via covalent bond formation).
2. Carbon has four valence electrons, so it can achieve a full outer energy level by forming four covalent bonds.
hope this helps
The most effective way to keep dry land from becoming more arid is to use sustainable agricultural practices.
The right answer is "plant a tree belt"
The event of increasingly arid dry land or desertification is an event where the land becomes a very dry lack of water, vegetation, and also wild animals.
