<span>Ozone is simply a molecule consisting of 3 oxygen atoms, which reacts strongly with other molecules. Ozone is created in the stratosphere when high energy uv radiation causes on O2 molecule to split. The free oxygen atoms collide and react with other O2 molecules to form O3.</span>
Production is highest where the solar uv is the greatest eg near the tropics, but once created, the ozone is then circulated towards the poles by the atmosphere. The amount of ozone in the stratosphere can vary with location, season and even day to day climatic conditions.
<span>The process of ozone creation is what makes the O3 in the atmosphere very effective at shielding the Earth from harmful uv radiation, which can cause many biological problems, such as skin cancer. However, due to its high reactivity, the uv found in the tropospher at ground level can aslo be dangerous as a toxic pollutant which is harmful to plants and lung tissue, and is a major cause of smog.</span>
Answer:
They have helical thickening of lignin in their walls to prevent collapse
Explanation:
the primary function of Xylem and its conducting vessels tracheids is to provide support and tranport water and minerals in plants.
Xylem vessels have layers of dead materials in the walls called LIGNIN. Lignin is a polymer; a very strong, hard materials that stop water passage through it,because it contains dead cells,
Therefore the presence of deposit of these strong impermeable, ligified walls in its walls prevent its collapse during mass flow of water of transpiration pull.
It is the second sentence. Organs are made up of tissues. Tissues are made up of cells.
The correct answer is option A. Carrying the genetic code and determining an organism's structure and function are the functions of DNA. It is the hereditary material in almost all other organisms. The information in a DNA is stored as codes that is composed of chemical bases.
