While we can use molecular clocks based on molecular sequence data to estimate the times at which various lineages diverged, we ultimately need the to calibrate the clocks.

A) morphology
B) fossil record
C) radiometric data
D) B and C
E) All of the answer options are correct.

Give examples of animals that live in sea and are considered mammals. ♡

Darrel conducted an experiment with the following procedure: fill two cups with ice water. place an uninflated balloon snuggly onto your left index finger. blow a little air into an identical balloon, and place it onto your right index finger. place both fingers into the cups of ice water. darrel noticed that his right finger felt warmer in the ice water than did his left finger. which of the following does the experiment show? a. air is a good radiator of heat. b. air is a good insulator of heat. c. air is a good conductor of heat. d. air is a good convector of heat.

The vaccine in a flu shot contains weakened flu viruses. how does a flu shot work with the immune system? a. it destroys lymphocytes. b. it destroys macrophages. c. it activates macrophages. d. it activates lymphocytes.