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:
Wheezing happens when the airways are tightened, blocked, or inflamed, making a person's breathing sound like whistling or squeaking. Common causes include a cold, asthma, allergies, or more serious conditions, such as chronic obstructive pulmonary disease (COPD).
Explanation:
A batsman is unlikely to score a century in every cricket match. This is an example of "partial reinforcement".
<u>Option: C</u>
<u>Explanation:</u>
Unlike constant reinforcement, partial reinforcement is only strengthened during certain times or time ratios, rather than emphasizing the action every single time. This method of arranging reinforcement is also called intermittent reinforcement after certain number of correct answers or certain interval of time. Thus here a batsman donot plan intentionally to make a century in every cricket match, but it goes random. Although when they need to score high on pressure, they force themselves to stretch as much possible which is not general.
