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Studentka2010 [4]
3 years ago
6

Why do you pass out if you lock your knees?

Biology
1 answer:
Inga [223]3 years ago
8 0
It's caused by blood pooling in the legs, so there's insufficient return to the heart and brain. Normally, moving one's legs helps to pump blood back to the heart through muscle contraction. Locking the knees makes standing still easier, but reduces use of the leg muscles. In some people, this pooling may lead to hypoperfusion of the brain and fainting, which is essentially the body's way of putting the brain and the legs and the heart at the same level.
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How is a trophic cascade (top down regulation) different from the traditional trophic pyramid (bottom up regulation)?
Sidana [21]

Top-down effects imply control through predation, including fishery, while

bottom-up effects imply control through food abundance, often thought to be driven by climate or nutrient load.

<h3>What is Top down regulation ?</h3>

The top-down effect refers to a higher trophic level influences the community structure of a lower trophic level through predation.

<h3>What is Bottom up regulation ?</h3>

The bottom-up effect means that a lower trophic level in the biological network affects the community structure of higher trophic levels by means of resource restriction

Learn more about Top down and bottom up regulation here:

brainly.com/question/18996262

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5 0
2 years ago
Which are examples of steroids?
kenny6666 [7]
Salutations!

<span>Which are examples of steroids?

Steroids is a construction collected of four- rings. They aren't quite lipids because it is a collection of four- rings. Cholesterol and vitamin D are examples of steroids. Vitamin D is formed by cholesterol because of metabolic reaction.

Thus, your answer is option A.

Hope I helped (:
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4 0
2 years ago
Read 2 more answers
1.If a DNA molecule has 40% Cytosine, what percent of it would be Adenine?
andrey2020 [161]

Answer:

The correct answer is -

1. Adenine - 10%

2. A-T and C-G always in DNA.

Explanation:

1. The total amount of all nitrogenous bases are equally 100% and which includes an equal amount of C and G and an equal amount of A and T in the DNA molecule.

So, Cytosine = 40%, Guanine= 40%

total = 80%

therefore, the A and thymine would be - 100 - 80 = 20

A+T = 20

A= 10, and, T = 10%

2. The complementary base pairing rule explains that DNA base pairs are Adenine always binds with thymine and cytosine bind with guanine only. Purine binds with pyrimidine always except - A-C or G- T.

7 0
2 years ago
A two-trait occurs when an individual has two dominant alleles but it is not possible to determine if that individual is homozyg
Alex17521 [72]

Answer:

This statement refers to Test Cross.

Explanation:

Generally a Test cross involving an individual with a homozygous recessive trait . When a single trait is being studies, a test cross is a cross between an individual with the dominant phenotype but of unknown genotype (either homozygous or heterozygous) with a homozygous recessive individual. If the unknown is heterozygous for a trait, then approximately half of the offspring will display the recessive phenotype. If all the offspring carry dominant phenotype, Then the unknown genotype is homozygous.

4 0
3 years ago
What can you know about the relationship between Escherichia coli and Entamoeba coli from their names?
Art [367]
Both are microorganisms
6 0
3 years ago
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