Hello!
An initial observation is the first thing a scientist notices about a topic before conducting the experiment. We can see that it is the first thing in the paragraph in this case, that dandelions grow as unwanted weeds in many lawns.
The hypothesis is the guess about the result of an experiment made before the experiment is conducted. In this case, it is that a weed killer (Killimal) would kill all the dandelions while leaving the grass healthy. This is not specifically a guess made by the scientist, but more like a prediction he wanted to verify.
An independent variable is the variable being changed in the experiment by the scientist. Here, it is whether Killimal was sprayed or not.
The dependent variable is the variable being measured, and the one being affected by the independent variable. His observation would be whether the grass and dandelions would be killed. This is because the weed killer would be directly affecting whether or not these would be killed.
The control variables are ones which are kept the same in the experiment as to not interfere with the final results. In this case, it would be the density of dandelions, the amount of sunlight, and the amount the plants were watered. These were kept exactly the same, as they could've affected the dependent variable if changed.
The control group was the one that is not impacted by the independent variable. The control group makes sure that it actually is the independent variable affecting the dependent, and it isn't some outside unknown variable. This would be the plot without the Killimal.
The experimental group is the one being experimented on from the independent variable. This would be the plot with the Killimal.
Hope this helps!
Answer:
The color of skin is influenced by a number of pigments, including melanin, carotene, and hemoglobin. Recall that melanin is produced by cells called melanocytes, which are found scattered throughout the stratum basale of the epidermis.
In order for me to assist you, you must attach an image of the graph. :)
The pH of the stomach in the digestive system is known to be very low, and acidic, so it can break the bonds between molecules, to which the nutrients diffuse into your blood, energizing you.
I think that it would be classified in the prokaryotic domain.