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3 years ago

The major advantages of a tissue-based compared to a mechanical-based heart valve prosthesis includes . .

Biology

1 answer:

mash [69]3 years ago

7 0

Answer:

reduced thrombogenicity.

Explanation:

For patients with significant heart valve disease, surgical options for treatment include valve repair or replacement. The choice between repair and replacement is influenced by a number of factors including age, type of the valve disease and other medical conditions. When valve replacement is performed, there are options of mechanical or tissue heart valves. These two classes of valves confer different characteristics and each have their advantages and disadvantages.

Mechanical valves: Mechanical heart valves are made from materials such as titanium and carbon. They usually consist of two leaflets and a metal ring surrounded by a ring of knitted fabric, which is sewn onto the heart in place of the original valve.The main advantage of mechanical valves is that they are very durable. However, these valves provide a surface on which blood clots can form easily. As a result, anyone who has been implanted with a mechanical valve needs to be on lifelong blood-thinning medication, such as warfarin, to prevent the development of blood clots that can cause heart attack or stroke

Tissue valves, also known as biological or bioprosthetic valves, are composed of animal or human tissue. The valves are derived from animal tissue such as porcine (pig), bovine (cow) and equine (horse) models, and then fixed with a preserving solution that may be mounted on a flexible frame to assist in deployment during surgery. As with mechanical valves, the bottom of a tissue valve is often surrounded by a ring of knitted fabric that is sewn onto the heart. In addition to animal-derived valves, a human tissue valve from a donor human heart, known as an allograft or homograft, may also be used as a replacement valve. Tissue valves can be used in open heart surgery or in a minimally invasive aortic operation known as transcatheter aortic valve implantation (TAVI).

Advantages of tissue valves compared to mechanical valves include the avoidance of lifelong warfarin therapy to prevent the development of blood clots.

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A gene that affects hair length in dogs has two alleles. The allele for short hair (L) is dominant

Lelechka [254]

Answer:

This question lacks options, the options are:

A. Only recessive alleles are inherited from homozygous parents.

B. Dominant alleles grow weaker as they are passed from parents to offspring.

C. Only the parent with a dominant allele can pass that allele to offspring in sexual reproduction.

D. A heterozygous parent has an equal chance of passing either the dominant allele or the recessive allele to offspring.

The answer is D

Explanation:

This question involves a single gene coding for hair length in dogs. The allele for short hair (S) is dominant over the allele for long hair (s). This means that allele 'S' will always mask the phenotypic expression of allele 's' in a heterozygous state.

According to the question, two heterozygous dogs (Ss) were crossed to produce 6 shortt-haired offsprings and 2 long-haired offsprings. An heterozygous organism is that which contains two different alleles for a particular gene i.e. a combination of dominant and recessive alleles.

Based on this, during meiosis or gamete formation, an heterozygous dog (Ss) will produce gametes with the short hair allele (S) and long hair allele (s) in equal proportion i.e. 50-50. When the two gametes containing the recessive alleles (s) produced by each heterozygous parent fuses, an offspring with a recessive phenotype (long hair, ss) is produced.

Hence, a long-hair

phenotype can appear in the offspring of two short-haired dogs because a heterozygous parent has equal chance of passing either the dominant or recessive allele to the offspring.

6 0

3 years ago

In a car accident, jane suffered a chest injury that resulted in impaired breathing and respiratory acidosis. how will her body

ehidna [41]

Her body compensate for imbalance by Kidney retain bicarbonate ions .An increase in hydrogen ion in the body causes the kidney excrete more acid.These lowers the PH of the blood since hydrogen ion are increased while bicarbonate ion are decreased

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3 years ago

2. What did you do differently to be successful without using your thumb?

klasskru [66]

Answer:

to be successful while not using my thumb, i used the rest of my fingers and my hand to grasp the object

Explanation:

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3 years ago

Rewrite this hypothesis so that its more useful when experimenting : bean plants will grow more slowly when exposed to acid rain

olasank [31]

If bean plants are exposed to acid rain, then it will grow slower.

4 0

3 years ago

Which of the following would have resulted from the functions of prokaryotes on early Earth?

frutty [35]

Hey!

Hope this helps...

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

A user mentioned in the comments of one of the answers deleted: "its B" < The user (<span>lolbae0806) had mentioned this...</span>

So I believe the correct answer is:

B.) More oxygen gas became present in the atmosphere.

6 0

3 years ago

Read 2 more answers