3. Asexual reproduction produces offspring with
A. half of a single parent's genes.
B. the same genes as the parent.
C. a mix of genes from two parents.
D. lots of genetic variation.
5. Fossils that consist of minerals that have filled in an open mold of an organism are called
B. natural casts.
C. preserved remains.
D. trace fossils.
10. Which of the following characteristics must a good index fossil have?
A. very rare, easy to identify, existed for a brief time, occurs in a local area
B. somewhat rare, hard to identify, existed for a brief time, widespread
C. common, hard to identify, existed for a long time, widespread
D. very common, easy to identify, existed for a brief time, widespread
13. The smallest unit of geologic time is a(n)
20. The bacterium shown in Figure 12.1 may have evolved into a mitochondrion after going through the process of
23. What do scientists estimate as the age of Earth?
A. 100 million years old
B. 4.6 billion years old
C. 10 billion years old
D. 3.8 million years old
25. The Miller-Urey experiment demonstrated that
A. organic molecules first could have come to Earth on a meteorite.
B. iron-sulfide bubbles may have acted as the first cell membranes.
C. liposome membranes containing organic molecules preceded true