Which summary below correctly describes what occurs during transcription?

I’ll mark brainliest

Yuri [45]

Answer:

B C and D

Explanation: A isn't as Eukaryotes contain double-stranded linear DNA molecules packaged into chromosomes

4 0

3 years ago

List all the electrical and mechanical events that occur within 1 heartbeat (in order). Also be able to state which are occurrin

eimsori [14]

Answer:

Phases of the Cardiac Cycle are Diastole and Systole

Explanation:

<h2>Cardiac Cycle Phases </h2>

(First Phase) Atrial contraction

This is the phase of atrial contraction.

In this fase, 80% of ventricular filling has been done passively even before the onset of atrial contraction, and the remaining 20% of ventricular filling is due to atrial contraction. The active filling of ventricles becomes valuable during physical activity.

When pressure in the atrium increases, blood rush into the ventricles through the opened mitral valve. During left atrium contraction, pressure and volume are transferred into left ventricle through opened mitral valve. Aortic valve is closed because pressure in aorta is greater than the pressure in left ventricle at this moment.

(Second Phase) Isovolumetric Contraction

The early phase of ventricular systole. When ventricles contract, there is a progressive increase in intraventricular pressure. This wil leads to closure of mitral valve. That produces first heart sound (S1) and little bulging of mitral valve into atrium causing the slight increase in the atrial pressure.

Intraventricular pressure progressively increases upto 80mmHg altought it is not competent enough to open the aortic valve.

At this moment ventricle is contracting with closed mitral and aortic valves. Meanwhile, intra atrium pressure is gradually increasing due to accumulation of blood returning from lungs into the left atrium. During the same phase, aorta pumps whatever blood it contains into more peripheral part of arterial tree due to its elastic nature.

This is the stage of ventricular contraction when backward valves are closed yet the forward valves are not opened. Ventricle is contracting as a closed chamber without any change in volume and size of the ventricle. We call it isovolumetric contraction of early part of ventricular systole.

(Third Phase) Rapid Ventricular Ejection

When pressure reaches to 81mmHg, aortic valve opens. This starts third phase of cardiac cycle. Ventricles keep on contracting, and there is a progressive increase in intraventricular pressure upto 120mmHg. During this phase, aortic valve opens and blood is ejected quickly into the aorta. At this point left ventricle and aorta behave as a single chamber.

The pressure changes occurred in the ventricles results in the transmission of pressure to aorta. Meanwhile left atrium continues receiving blood from the lungs.

(Fourth Phase) Slow Ventricular Ejection

In this phase atrium is still behaving as reservoir of blood and the pressure is keep on building. Mitral valve is closed. Ventricles are still contracting but intraventricular pressure starts falling, due to ejection of blood . Hence, pressure in aorta also starts falling, but intraventricular pressure is still more than aortic pressure.

Aortic valve remains open leading to slow ejection of blood into aorta. Elastic aorta keeps on squeezing the blood and pumps it into peripheral arterial tree.

(Fifth Phase) Isovolumetric Relaxation

In this phase ventricles start relaxing. Intraventricualr pressure falls quickly. In the beginning, as soon as the ventricular pressure becomes less than pressure in aorta, aortic valve closes.

Even though pressure in ventricle is falling, it is still high enough compared to pressure in atrium. Ventricle is relaxing with closed valves and it is known as isovolumetric relaxation. During this phase atrium is still behaving as reservoir of blood.

(Sixth Phase) Rapid Passive Ventricular Filling

When left ventricle start relaxing, pressure in left ventricle start dropping until it reaches the point where pressure in the ventricle becomes less than the pressure in atrium, leads to opening of mitral valve. Blood which was previously accumulated in atrium will rush into ventricle. This quick filling is done without atrial contraction.

(Seventh Phase) Slow Passive Ventricular Filling

As atrioventricular valve open, blood coming to atrium rushes into the ventricle. Here atrium is not acting as reservoir.

7 0

4 years ago

1. Although their concentration in the atmosphere is lower than carbon dioxide, ____________________ absorb Earth's outgoing rad

cestrela7 [59]

Answer:

1. Trace gases 2. Climate feedback mechanisms 3. Positive feedback mechanisms 4. Aerosols 5. Negative Feedback Mechanisms 6. Positive feedback mechanism

Explanation:

Using the knowledge of global warming as a result of climate change, we can provide the following answers to fill in the gap:

1. Trace gases

Greenhouse gases provides a natural effect known as greenhouse effects. This effect is achieved when greenhouse gases trap and absorb infrared radiation, in form of heat, thereby slowing down the loss of he into space. This effect ensures the earth remains habitable as the temperature of the earth would drop causing freezing of the earth. Life would almost not exist in the absence of this phenomenon caused by greenhouse gases. Carbon dioxide accounts for the highest percentage by volume of the total greenhouse gases found in the atmosphere. Trace gases such as argon are found in minute quantities in the atmosphere. Hey also have the ability to absorb infrared rays.

2. Climate feedback mechanisms

Climate feedback mechanism is a kind of continuous cycle that describes how the system responds to the changes it is being impacted on. The change can either produce an increase or decrease in the warming effect. There are basically 2 types of feedback mechanism: Positive and Negative feedback mechanism. A positive feedback mechanism involves changes that reinforce the increase of the temperature of the system, while negative feedback mechanisms involves processes that reduce the effect of warming, causing a drop in temperature of the system.

3. Positive feedback mechanisms

Effects that involve processes that helps in pushing the temperature of the climate system up, thereby producing additional warming effect on the initial warming trend of the system are said to be identified as Positive feedback mechanisms. Examples of such effects is melting of ice, especially as more pronounced in polar regions.

4. Aerosols

Aerosols can be in form of fine solid particles or liquid droplets suspended in the air. Examples of aerosols include dust, fog, smoke or air pollutants. They have the ability to scatter solar radiation and change the reflectivity of the earth. These effects created by aerosols have a cooling effect on the climate system, as a against the effect produced by greenhouse gases. The effects caused by aerosols are examples of negative feedback mechanisms.

5. Negative Feedback Mechanisms

An example of such effects is the effect produced by aerosols. Such effect cools the system which is opposite to the warming trend of the system.

6. Positive feedback mechanism

Decrease in surface reflectivity, and increase in surface solar energy absorption as a result of reduced sea ice would further reinforce the warming trend of the system, such change a positive feedback mechanism.

6 0

4 years ago

Who is gregor mendel

snow_tiger [21]

Answer:

Gregor Mendel created the punnett square.

Explanation:

5 0

3 years ago

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LOVE YOUR LIFE...because once you start to enjoy it... it will be too late

Elanso [62]

Answer:

Awww ♡

Explanation:

Thank you

LOVE YOUR LIFE...because once you start to enjoy it... it will be too late

LIFE IS SHORT SO ALWAYS BE POSITIVE :)

love you! you deserve the best :) <33333 do the same

6 0

3 years ago

Read 2 more answers