<span>by collecting “proxy data” from tree rings, ice cores, and historical records</span>
This zone is called as the zone of aeration. It is present between the earth's surface and the water table, and its main constituents are the soil and rocks. The pores which are present in this zone are partly filled with water, and may mix up with air, causing aeration.
Answer:
C. Properties that can change the chemical nature of matter.
Explanation:
Chemical properties is a characteristic of a chemical substance observed when it undergoes a chemical reaction on seeing its precipitation. On knowing the chemical properties of a substance it aids in separation, purification and classification of a compound. some examples of chemical properties are as follows:
1. Toxicity
2. Inflammability
3. Reaction with other chemicals
4. Oxidation
ANSWER:
Most types of cancer are believed to begin with a random genetic mutation. This is followed by mutations, which endow the cancer cells with properties allowing them to grow without normal controls to become a tumor.
Mutation is any change in the DNA sequence of a cell. Mutations may be caused by mistakes during cell division, or they may be caused by exposure to DNA-damaging agents in the environment.
Genetic Mutations that lead to cancer cell formation can occur in two forms:
1. GROWTH-PROMOTING GENES are commonly mutated in cancer cells, becoming SUPER-ACTIVE and producing cells that are too strongly stimulated by growth receptors.
2. Mutations can INACTIVATE the genes that suppress cell proliferation or those that signal the need for apoptosis. These genes are known as TUMOR SUPPRESSOR GENES.
The writing materials,the envelopes and the stamps are all made of paper and this led to a great waste as the papers have to be disposed after use. This is not the case with electronic mails. Electronic mails do not need paper at all and it has drastically reduce the amount of papers that is used in writing letters.
I hope this helps :)
