Between the 6th and 21st days of the menstrual cycle
Answer:
Independent variable: Adding/not adding soil.
Dependent variables: Does the plant grow? Amount of leaves, plant length.
Controlled variables: Type of plant used, amount of sunlight received, pot used for plant, amount of water given, temperature of soil, etc.
Explanation:
Independent variable: The thing that you want to change. To see if plants need soil to grow, you would need to either add or remove soil altogether.
Dependent variables: The thing that is being measured. By adding your independent variable, you should be able to answer certain questions.
Controlled variables: Things you want to keep the same for each experimental group. For example, if you used different plants, your results could be affected negatively as some plants might rely on soil less than others/grow at a slower or faster pace.
Answer:
The correct answer is C) arachnoid mater.
Explanation:
Arachnoid mater, along with pia mater and dura mater, form the <u>meninges</u>, a very thick membrane that protects the brain and the spinal cord. The arachnoid mater is in the middle of the other two layers and it is very important since it holds the <u>cerebrospinal fluid (CSF)</u> in its interior. Arachnoid mater has finger-like projections that enter the dural venous sinuses and are called <u>arachnoid villi</u>. These villi are responsible for the diffusion of CSF into the blood.