Study the image about geologic time. A geochronological scale measured in Millions of Years Ago or M Y A. Cenozoic era: Paleogene period, 66 to 23 M Y A, diatrima, many types of mammals, smilodon. Neogene period, 23 to 2.6 M Y A, smilodon, mammoth. Quaternary period, 2.6 to today, human, mammoth.

During which period did humans first appear on Earth?

Quaternary
Neogene
Paleogene
Cenozoic

Quaternary

Explanation:

The Quaternary period which began around 2.6 million years ago or 2,588,00 years ago is known as the Age of humans.

During this period, the tectonic planets are in a place they are today but the climate was cold and ice glaciers started retreating.

During this period, the evolution of mammals reached on peak and the hominid lines began to evolve as the fossils of the first human belonged to this period. Homo erectus for the first time appeared at the beginning of this period and then evolved later into modern humans after they travelled to Europe and Asia.

Thus, Quaternary is the correct answer.

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is correct hope this   also i learnd this in middle school

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.