Chapter 18 16. The Cambrian explosion a. killed the dinosaurs. b. produced the c

Question

Chapter 18

16. The Cambrian explosion

a. killed the dinosaurs.

b. produced the carbon that is now here on Earth.

c. was a sudden increase in biodiversity.

d. released a lot of carbon dioxide into the atmosphere.

19. Mutations are

a. changes to an organism’s DNA.

b. changes in the appearance of the organism.

c. deadly to the organism’s children.

d. changes in the whole species.

20. The habitable zone is the place around a star where

a. life has been found.

b. atmospheres can contain oxygen.

c. liquid water exists.

d. liquid water can exist on the surface of a planet.

22. Carbon is a favorable base for life because

a. it can bond to many other atoms in long chains.

b. it is nonreactive.

c. it forms weak bonds that can be readily reorganized as needed.

d. it is organic.

23. A thermophile is an organism that lives in extremely ______ conditions.

a. salty

b. hot

c. cold

d. dry

24. Life first appeared on Earth ______ of years ago.

a. thousands

b. hundreds of thousands

c. millions

d. billions

25. Astronomers think that intelligent life is more likely to be found around stars of types F, G, K, and M because

a. those stars are hot enough to have planets and moons with liquid water.

b. those stars are cool enough to have planets and moons with liquid water.

c. those stars live long enough for life to begin and evolve.

d. those stars produce no UV radiation or X-rays.

Explanation / Answer

16.option c

19 a

20 d

22 a

23 b

24 d

25 b

Thank you

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.