The control group in this experiment is the group of tomatoes that do not receive any fertilizers i.e. fourth tomato plants.
<h3>What is Fertilizer?</h3>
Fertilizer may be defined as any chemical or natural substance which is added to the soil with the intention of enhancing productivity.
All those groups of tomatoes in which fertilizers are added behave as a reference group while those in which fertilizer is not added behave as a control group.
Therefore, it is well described above.
To learn more about Fertilizers, refer to the link:
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Bottom feeders are aquatic animals that feed on the bottom of a body of a water. Crayfish is the bottom feeder. It is not active swimmer, it feed on stationary or slow pray, so it does not have such a streamlined body necessary to reduce drag during swimming. Its mouth is located on the underside of their heads and that way mouth is closer to the bottom where their food is.
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The answer is Integumentary System. it is the organ framework that shields the body from different sorts of harm, for example, loss of water or scraped spot from outside. The framework involves the skin and its limbs.
The integumentary system comprises of the skin, hair, nails, organs, and nerves. Its principal work is to go about as a hindrance to shield the body from the outside world. It additionally capacities to hold body liquids, ensure against ailment, dispense with squandering items, and direct body temperature.
There are so many examples for that in different areas, like biology experiment carried out in our lab recently.
Here's one link:https://www.creative-biogene.com/support/Knockout-Cell-Lines-in-Antibody-Screening-and-Validation.html
