Insects, and some other invertebrates, exchange oxygen and carbon dioxide between their tissues and the air by a system of air-filled tubes called tracheae. Tracheae open to the outside through small holes called spiracles.
Answer:
D. An observation is based on evidence, an inference is not.
Explanation:
When you infer something, you're basically guessing at it, while an observation is something that you can see and prove.
The best answer would be:
Unconditioned stimulus
In Pavlov's experiment on conditioning the food was the unconditioned stimulus that triggers a reflex or natural behavior. Think of it like something that makes you do something automatically.
For example, the food. When the dog smells food, it salivates. This is unconditioned because without teaching the dog, it automatically responds by salivating.
The statement that best represents how structure relates to function is as follows: a deer's horizontal pupils help it scan the horizon for predators (option C).
<h3>What is structure in biology?</h3>
A structure, according to biology, is an arrangement or organization of parts to form an organ, system, or living thing.
The structures found in living organisms are usually function-specific. Examples of common structures in living organisms and their respective functions are as follows:
- Radula in snails - feeding
- Eyespot in Euglena- light sensing
- Claws in carnivores- for holding prey
Therefore, the statement that best represents how structure relates to function is as follows: a deer's horizontal pupils (structure) help it scan the horizon for predators (function).
Learn more about structure and function at: brainly.com/question/14419215
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