<span>Certainly. Every organism has a variety of different characteristics. One person writing a key might choose to use different characteristics than another person would use.
For example: Here's a key for separating fish, snake, frog and mouse
1.
A. Has scales on its skin ... 2
B. Has no scales on its skin ... 3
2.
A. Breathes with gills - fish
B. Breathes with lungs - snake
3.
A. Has hair or fur - mouse
B. Has no hair or fur - frog
Here's a different key for the same four animals:
1.
A. Has four legs ... 2
B. Does not have 4 legs ... 3
2.
A. is warm-blooded - mouse
B. is cold-blooded - frog
3.
A. has fins - fish
B. has no fins - snake</span>
Between A and T there are 2 hydrogen bonds, while there are 3 between C and G.
<span>C. Cells, Tissues, Organs, Organ Systems
The answer is C. Cells are the fundamental unit of life. Without them, life would not possibly exist. Well that is according to the cell theory, which states that cells are the basic unit of life, cells came from pre-existing cells and cells make up living organisms.
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Answer:
Encyclopædia Britannica, Inc. The forearm and the lower leg have two long bones each. In the forearm are the radius—on the thumb side of the forearm—and the ulna; in the lower leg are the tibia (the shinbone) and the fibula. The radius corresponds to the tibia and the ulna to the fibula.
Explanation:
