At one point, scientists observed that the ozone shield was getting thinner. they warned that the loss of the effectiveness of this shield may lead to an increase in
(1)allergies to ozone
(2)mutations that lead to cancer
(3)viral diseases, such as aids
(4)ice formation at the poles

enhanced global partnerships and exploration capabilities may advance international preparedness for protecting the earth from catastrophic events such as some asteroid strikes, advancing collaborative research on space weather and protecting spacecraft by developing new means for space debris removal.

1. amino acid refers to the fundamental building block of proteins, comprising of an amino group and a carboxyl group.

2. catalyst refers to any substance, which increases the rate of chemical reaction without being used up in the reaction.

3. a complex molecule containing he genetic code is dna or deoxyribonucleic acid.

4. an enzyme refers to a molecule of protein, which is unique in accelerating up a particular chemical reaction in the biological systems.

5. nucleic acid refers to an sequence of sugars, phosphates, and nitrogenous bases, for example, dna and rna.

6. a protein refers to a large, composite organic molecule comprising of a huge number of amino acids associated together with the of peptide bonds.

7. rna refers to a nucleic acid that takes part in the production of proteins.

8. substrate refers to a compound, which takes part in a chemical reaction, and is chemically modified by the reaction.

i think the answer is a.keratin is the pigment responsible for skin color.

whats the drop down answers ?

explanation: