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:
c lower oxygen levels
Explanation:
the higher up the person is the closer to the atmosphere so there is less oxygen
I think the answer is B because it happens slowly and through natural selection
Answer:
temporal reproductive isolation
Explanation:
The correct answer would be temporal reproductive isolation.
<u>Reproductive isolation</u> generally refers to series of biological mechanisms or processes that prevent members of different species from mating/fertilization or prevent the product of their mating to be invalid.
Some reproductive isolation processes prevent members of different species from mating or prevent fertilization as a result of mating. These processes are known as pre-zygotic reproductive isolation mechanisms.
Some other processes ensure that the product of fertilization (when it occurs) is invalid. These are known as post-zygotic isolation mechanisms.
<em>A good example of the pre-zygotic reproductive isolation process is </em><em>when closely related by different species bloom at different times</em><em>. This will prevent mating or cross-pollination to happen between the different species. This is known as temporal reproductive isolation.</em>
