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2 years ago

The blood-brain barrier is effective against ________.

1 answer:

8 0

The blood-brain barrier is effective against the brain itself mostly because it, like a cell membrane, Controls what nutrients and other things that go into and out of the brain.

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You have formulated a hypothesis. Pineapples contain more vitamin C. than oranges. to test this hypothesis you measure vitamin C

Pavel [41]

Answer:

d. The dependent variable is the vitamin C levels in the pineapples and oranges.

Explanation:

Select all the statements that are true about this experiment.

a. The independent variable is temperature. NO, temperature, as well as rain and sunlight are controlled variables and are not being evaluated in the experiment.

b. the control group in the experiment is the oranges. NO, there is no control group in this particular experiment.

c. The type of fruit is a controlled variable. NO, the type of fruit is the independent variable.

d. The dependent variable is the vitamin C levels in the pineapples and oranges. YES. According to your hypothesis, the vitamin C levels depend on the type of fruit.

3 0

1 year ago

Receipt of extracellular signals can change cell behavior quickly (e.g., in seconds or less) or much more slowly (e.g., in hours

balandron [24]

Answer:

A. Molecular changes such as extracellular signals on extracellular ligands can result in quick changes in cell behaviour. One example is insulin. Upon insulin binding on the receptor on the cell membrane, the cell release GLUT4 transporters (for muscle cells) to increase uptake of glucose.

B. Slow changes in cell behaviour can be observed for other lipophilic hormones or intracellular receptors such as glucocoortoid or estrogen which reacts with receptors in the cells.

C. Insulin is required to maintain a constant blood glucose level and hence levels of insulin has to be mediated in correspondence to the blood glucose levels. Fast acting signalling is thus required for homeostasis of blood glucose levels. Where for such lipophilic hormones such as steriods, glucocortoid, these hormones tend to have a longer lasting effect and hence results in a slow change.

6 0

1 year ago

Sympathetic nerves may leave the spinal cord at which vertebra?

alisha [4.7K]

Answer:

b. first thoracic

Explanation:

Sympathetic nervous system is one of the divisions of the autonomic nervous system. The other divisions are parasympathetic nervous system and enteric nervous system.

Autonomic nervous system is composed of preganglionic neurons and postganglionic neurons.

Similarly, the sympathetic nervous system is composed of postganglionic and preganglionic neurons.

The cell bodies of preganglionic neurons of sympathetic nervous system is found in intermediolateral cell columns of spinal cord segments T-T12 and L1-2 or 3. Therefore, sympathetic nervous system is also called thoracolumbar division.

The cell bodies of parasympathetic nervous system are found in the brainstem nuclei which exit via cranial nerves 3, 7, 9, 10 and also in the sacral spinal cord segements S2-4, therefore parasympathetic nervous system is also known as craniosacral division.

QUESTION:

b. first thoracic

This is the correct answer choice as sympathetic nervous system cell bodies are found in intermediolateral cell column of T1-12 and L1-2 or 3 spinal cord segments. Hence, a sympathetic nerve is most likely to leave via first thoracic vertebra.

Third lumbar is less likely as sympathetic nervous system does not extend to this level in every individual.

7 0

2 years ago

A study is being done to test the affects of habitat space on the size of fish populations. different sized aquariums are set up

qwelly [4]

Although not specified, I am assuming that you want to identify the different variables and groups of this case. To answer this, the different typical factors that make up an experimental set up include: 1) dependent and 2) independent variables; 3) controlled variables; as well as the 4) control and 5) experimental group.

The dependent variable in this case is: the size of the population. While the independent variable is: the habitat space. Controlled variables in this experiment include: type and amount of food, cleanliness of the aquarium, and water temperature. The experimental group are simply the fish being observed. There are no controlled groups in this case depending on your definition. Controlled groups are usually the reference point or standard in experimental setups but this experiment wants to look at the differences of the goldfish with each other and not necessarily to a one particular goldfish and hence no controlled group.

The dependent variable is called as such because it is the one that changes depending on the factors given and is usually the one being observed. The independent variable is named as such because it remains the same throughout the experiment.

7 0

1 year ago

Read 2 more answers

Which of the following best describes why the disks rose to the surface faster in the more concentrated hydrogen peroxide soluti

enyata [817]

The higher substrate

Hope this helps ^-^ Diamonds is the name Thanks

7 0

1 year ago