3 | P a g e
Answer: 2.5 million
Explanation: Although humans are relatively recent arrivals on Earth, they have only been
present for approximately 2.5 million years, and only in the last 300,000 years have humans
begun to resemble the creatures we are today.
Question: _____ is the study of viruses, which share some traits with living things but not all
of them.
Answer: Virology
Explanation: Virology examines viruses, which can attack living things, spread diseases, and
reproduce, but do not fit the criteria that scientists use to define life.
Question: The _____ describes that all living things are composed of one or more cells, the
cell is the basic unit of life, and new cells arise from existing cells.
Answer: unified cell theory
Explanation: The unified cell theory was proposed by botanist Matthias Schleiden and
zoologist Theodor Schwann by the late 1830s, establishing fundamental principles about
cellular organization of life.
Question: According to the theory of _____, the origin of life on earth is the result of a slow
and gradual process of chemical evolution that probably occurred about 3.8 billion years ago.
Answer: Chemical Evolution
Explanation: This theory, also known as the physical-chemical hypothesis or materialistic
theory, was proposed by Russian scientist A.I. Oparin in 1923 and English scientist J.B.S.
Haldane in 1928.
Question: The theory of _____ states that God, the All-Powerful, created all the different
forms of life that exist today on planet Earth.
Answer: Special Creation
Explanation: According to this theory, all the various forms of life on Earth were created by
a Supreme Being at once, and this approach to research is predicated on the idea that the
Bible should be taken as a perfectly accurate account.