To prevent blood flowing back after each heartbeat. They ensure that the blood flows only in one direction (back to the heart).
Describe the behavior of brown bats
Answer:
because the beaks are different and since they prefer other avaliable seeds.
because the population changes over time its called natural selection, in darwins drawings there were extremely different from eachother.
because when he drew normal finches and went to galapagos islands he saw that there were also finches but they looked completely different and he analyzed their beaks. there are animals who change over natural selection
Explanation:
<span>sperm, blood, hair with attached tissue</span>
