Question

can you answer these questions

1. Thylacosmilus is a marsupial, and Smilodon is a mammal. Thylacosmilus and Smilodon both have saber teeth, but they do not share an ancestor that had saber teeth. What are saber teeth for these organisms?
analogous structures
homologous structures
vestigial structures
mutated structures

2. Why are the Miller-Urey experiments essential to the theory of evolution?
They showed that life can only come from life.
They showed that electricity can create life.
They showed how organic molecules could be made from Earth's early atmosphere.
They showed the role that natural selection played in the evolution of modern day organisms.

3. Which best describes eras and periods?

Eras have a smaller time span than periods.
Eras and periods are independent of each other.
Eras and periods both appear at the start of the Cambrian period.
Eras were more recently established on the time scale than periods.

4. Consider the generalized cladogram of fish.

A cladogram is shown. At point B, the organism shares jaws but not bones.

A fossilized fish is found that has jaws but no true bones. Where does this fossil belong on the cladogram?
A
B
C
D

Answer 1

1. analogous structures
- Thylacosmilus and Smilodon evolved saber teeth independently (convergent evolution), so the saber teeth are analogous.

2. They showed how organic molecules could be made from Earth's early atmosphere.
- The Miller–Urey experiments produced organic compounds (like amino acids) from simple gases and electrical sparks, demonstrating a plausible route to prebiotic molecules.

3. None of the given choices are correct. Correct relationship: eras are larger time divisions than periods; periods are subdivisions of eras.
- (Eon > Era > Period > Epoch > Age.)

4. B
- The fossil has jaws but no true bones, so it fits at the node where jaws appear but bones have not yet evolved (point B).