Answer:
The observed image will not be sharp
Explanation:
When 100x microscope objective lens is being used, light refraction in the air is enough high to produce image alterations. Image distortions can be minimized by immersion oil because this liquid has a higher refractive index than air. However, light refraction is not usually noticeable when using 4x, 10x and 40x objective lenses. Moreover, this image will not be sharp after putting oil on the slide and going back to the 40x objective, it is for that reason that the 40x is called 'high dry' lens. In consequence, it is required to clean the immersion oil off the 40x objective. In general, it is required to to remove the oil and refocus off the slide and lens immediately after oil immersion (it can be done by using an oil-soluble solvent).
The answer should be reptiles!
The characteristics of reptiles are:
1. They are four-legged
2. They have an outer covering of scales
3. They breathe with the aid of lungs
4. Although most reptiles lay eggs, some also give birth to live young (fertilise internally)!
I hope this helps! :)
C) Crops may cause an increase of allergic reactions in humans.
Answer:
A control variable is the variable in the experiment that does not change.
Explanation:
If you are testing how seeds grow in different types of water, and you add 1tbps of salt to one pot of water with the plant, and then added 2tbps to another pot of water with the plant. The control variable in this experiment would be the water with no salt because it was not altered.
FYI I did not pull from google. Good luck!
Answer:
A. I think A is the answer.
Explanation:
