B. One
because an independent variable is something you change. So in a scientific experiment you only change one thing. If you happen to change more than one thing then the test becomes unfair therefore you should repeat and make sure that only one thing is changed this time.
Answer:
Vertebrates contain nervous system which is highly specialized organ.
Explanation:
The nervous system is the complex system in the vertebrate body which is composed of central nervous system that contain brain,spinal cord and peripheral nervous system which contain cranial nerve, spinal nerve,involuntary nerve etc.
The nervous system contain neurons that mainly transmit signal to the different parts of the body.
The peripheral nervous sytem contain somatic and visceral part.
The grey matter and white matter are the 2 areas in vertebrate nervous system.
Answer:
Trees have to adapt to their environments in order to survive them, from the shape of their leaves to the size of their branches. They also have had to adapt the shape of their crowns to the kind of climate they live in so that they may have better chances at survival.
In warm areas with lots of sunlight for instance, you will see broad cones as the tree takes advantage to get as much sunlight as it can. In colder areas where snow is abundant, trees will be conical in shape so as not to gather too much snow when it falls.
