Question

can you answer these
A scientist is trying to determine the relationship between clams, snails, and squid. When she generates a molecular clock, she is surprised to see that clams and squid are more closely related than clams and snails. Which did the molecular clock data show?
Clams and squid have been evolving separately for a longer time than clams and snails.
Clams and squid have been evolving separately for a shorter time than clams and snails.
Clams and snails have more in common genetically than clams and squid.
Clams and snails are more similar in related structures than clams and squids.

Horses and zebras can be bred to produce a zorse, which is infertile. Which is most likely the reason zebras and horses are considered separate species?
They cannot breed.
Their offspring cannot breed.
They look different from each other.
They are found in different habitats.

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.

Henry was studying two populations of the same species of lizards. One population lived on an island and the other lived on the mainland. Both populations were affected by a hurricane that hit the island and the mainland with equal force. A year later, Henry was testing the gene frequency and saw a decrease in genetic variation in the island species, but not in the mainland species. Which best describes a conclusion he might have reached?
Gene flow greatly affects small populations, but large populations can recover.
Genetic drift greatly affects small populations, but large populations can recover.
Gene flow greatly affects large populations, but small populations can recover.
Genetic drift greatly affects large populations, but small populations can recover.

Jezelyn needs to create a project that shows geographic isolation in action and decides to make a video. Which of the following would make the best project?
a video that shows lemur species that have different grooming behaviors.
a video that shows the island of Madagascar with lemur populations separated from the mainland.
a video that shows lemurs with different feeding times living together.
a video that shows a lemur interacting with other animals in its habitat.

Answer 1

1) Clams and squid have been evolving separately for a shorter time than clams and snails.
- Molecular clocks measure time since common ancestry; closer relationship = less time since divergence.

2) Their offspring cannot breed.
- Horses and zebras can produce a zorse, but it is infertile, so they are separate species by the biological species concept.

3) They showed how organic molecules could be made from Earth's early atmosphere.
- Miller–Urey demonstrated formation of amino acids and other organics from simple gases and energy inputs.

4) Genetic drift greatly affects small populations, but large populations can recover.
- A hurricane caused a loss of genetic variation in the small island population (bottleneck/genetic drift), but the larger mainland population was buffered.

5) A video that shows the island of Madagascar with lemur populations separated from the mainland.
- Geographic isolation (physical separation) is best illustrated by populations separated by a barrier like an ocean/island.