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seropon [69]
3 years ago
11

Opening and closing of the heart valves is caused by

Biology
1 answer:
storchak [24]3 years ago
6 0

Answer:

The pressure differences on either side of the valve.

Explanation:

The heart valves open and close passively because of pressure differences on either side of the valve. When pressure is greater behind the valve, the leaflets are blown open and the blood flows through the valve. However, when pressure is greater in front of the valve, the leaflets snap shut and blood flow is stopped.

Hope this helps!

have a blessed day

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Assume that in cattle a spotted coat is dominant to an even coat, short horns are dominant to long horns, and the traits for coa
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Answer:

C. 1/4

Explanation:

Let's assume that the allele for the spotted coat is "S" and the one for the even coat is "s". The allele "L" gives short horns while the recessive allele "l" imparts long horns. The genotype of the cattle heterozygous for both traits would be SsLl. A cross between two heterozygous cattle would produce progeny in following phenotype ratio=

9 spotted coat and short horns: 3 even coat and short horns: 3 spotted coat and long horns: 1 even coat and long horns.

Therefore, the proportion of the progeny with long horns = 4/16= 1/4

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Scientists build models based on what they know from previous research to derive testable hypotheses. Independently, both Watson
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Answer:

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The acidic chyme entering small intestine is neutralized by the bile.
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Once food is in the small intestine, it stimulates the pancreas to release fluid containing a high concentration of bicarbonate. This fluid neutralizes the highly acidic gastric juice, which would otherwise damage the membrane lining of the intestine, resulting in a duodenal ulcer.

Hope it Helped.

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Why is genetic variation important in a population?
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