D oxygen there was no free oxygen on the earth
Answer:
My guess would be an energy source, water, and an atmosphere.
Explanation:
Whatever lives there is going to need energy and water to survive. The atmospheric layer will protect the planet like ours protects Earth. Hope this helps! :)
Answer:
1. Iterative homology: e.g. antenna and leg of fiddler crab
2. Ontogenetic homology: e.g. radular teeth of veliger, feathers of chicken and hen
3. Di-polymorphic homology: e.g. white and brown feathers of hen races, chelae of male and female of fiddler crabs
4. Supraspecific: e.g. chelae of fiddler crab, chelae of lobster, feathers of hen and pheasant
Explanation:
As water vapor rises in the atmosphere, it cools and changes into liquid cloud droplets in a process called condensation