Why is the claim of fossilized life in the Martian meteorite ALH84001 controversial?
A) it is doubtful that the rock actually came from Mars
B) the proposed fossilized organisms in no way resemble any kind of life found on Earth
C) the rock is too young to have fossilized life within it
D) there are many possible nonbiological explanations for the observed evidence
Question 2
A star less massive than the Sun will have
A) an identical lifetime as the Sun because although its overall mass is lower, the mass of its nuclear burning core is the same
B) a shorter lifetime because it has less fuel to burn
C) a longer lifetime because although its overall mass is lower, the mass of its nuclear burning core is larger
D) a longer lifetime because its central core is cooler and less dense
Life cycle of Obelia, a colonial cnidarian.
Hepatitis B Life Cycle
W. A. Rogers’s engraving, “Out of the Game,” showed one injured boy tending to another. It appeared
Personality over the Life Span
Fossilized Leaf