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2 years ago

Why is genetic variation within a population essential for evolution?

1 answer:

8 0

Genetic variation is essential for natural selection because natural selection can only increase or decrease frequency of alleles that already exist in the population. Genetic variation is caused by: mutation. random mating between organisms.

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Describe the plate motions along the Himalayan Mountains. Do you think these mountains are getting larger, smaller, or staying t

artcher [175]

<h2>Himalayas </h2>

Explanation:

Once, all the world’s landmass was connected, forming one super-continent known as Pangea
About 200 million years ago, tectonic forces broke apart this giant continent into pieces, eventually forming the continents that are known today
As convection currents worked independently on the plates associated with these new continental pieces, the plates and their respective continents began to drift across the globe to their present-day geographical locations
Eighty million years ago, India was approximately 6400 km south of the Eurasian plate, separating the two was the Tethys Sea
The Indo-Australian tectonic plate – containing the continent of Australia, the Indian subcontinent, and surrounding ocean – was pushed northward by the convection currents generated in the inner mantle
For millions of years, India made its way across the sea toward the Eurasian plate
As India approached Asia, around 40 million years ago, the Tethys Sea began to shrink and its seabed slowly pushed upwards
The Tethys Sea disappeared completely around 20 million years ago and sediments rising from its seabed formed a mountain range
When India and Tibet collided, instead of descending with the plate, the relatively light sedimentary and metamorphic rock that makes up the subcontinent of India pushed against Tibet, forcing it upwards, and created a massive mountain fold, The Himalayas
This process hasn’t stopped, the Indo-Australian plate is still moving toward Eurasia, still pushing Tibet upwards
The Himalayas continue to rise by an average of 2 cm each year and the highest mountains are only getting higher

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3 years ago

"Explain how and why de-oxygenated blood is pumped to the lungs and is then returned to the heart were the blood now rich with o

Jlenok [28]

<h2><u>Heart and lungs:</u></h2>

The upper chamber of the heart is called atrium and lower chamber of the heart is called ventricles.

The blood circulation in the heart is basically under the functioning of three blood vessels namely:

<h3><u>Arteries: </u></h3>

They start with the aorta, the huge vein leaving the heart.
Veins divert oxygen-rich blood from the heart to the majority of the body's tissues.
They branch a few times, decreasing and littler as they convey blood more remote from the heart.

<h3><u>Capillaries: </u></h3>

These are little; flimsy blood vessels that associate the arteries and the veins.
Their dainty dividers permit oxygen, supplements, carbon dioxide, and other waste items to go to and from our organ's cells.

<h3><u>Veins: </u></h3>

These are the blood vessels that return blood to the heart; this blood needs (oxygen-poor) and is wealthy in waste items that are to be discharged or expelled from the body.
Veins become bigger and bigger as they draw nearer to the heart.
The unrivaled vena cava is the huge vein that brings blood from the head and arms to the heart, and the second rate vena cava brings blood from the mid-region and legs into the heart.

6 0

3 years ago

Suggest why captopril or other ACE inhibitors might fail to lower a patient's blood pressure?

rjkz [21]

Answer:

Angiotensin-converting enzyme (ACE) inhibitors are commonly prescribed to treat high blood pressure, heart problems and other conditions. Find out how they work and their possible side effects.

Angiotensin-converting enzyme (ACE) inhibitors help relax veins and arteries to reduce blood pressure. ACE inhibitors prevent an enzyme in your body from producing angiotensin II, a substance that narrows your blood vessels. This narrowing can cause high blood pressure and force the heart to work harder. Angiotensin II also releases hormones that raise blood pressure.

In addition to high blood pressure, angiotensin-converting enzyme inhibitors prevent, treat or improve symptoms in conditions such as the following:

Coronary artery disease

Heart failure

Diabetes

Certain chronic kidney diseases

Heart attacks

Scleroderma: a disease that involves hardening of the skin and connective tissues

Migraines

The doctor may prescribe other medications in addition to an angiotensin-converting enzyme inhibitor, such as a diuretic or a calcium antagonist. Angiotensin-converting enzyme inhibitors should not be taken together with angiotensin receptor blockers or with direct renin inhibitors.

Angiotensin-converting enzyme inhibitors work better for younger people than for older people. They also work better for white people than for black people. The doctor may recommend a different medication.

7 0

3 years ago

Dracunculus medinensis is a parasite that can grow to be one meter long, and which humans can acquire through contaminated drink

stepan [7]

Answer: Nematoda

Explanation: The Dracunculus medinensis is a parasite that is often referred to as a roundworm. The answer Nematoda is correct because is is the phylum that classifies roundworms and is greek for "roundworms"

4 0

2 years ago

The Meselson-Stahl experiment provided the first experimental evidence that: A. Newly synthesized DNA in E. coli has different n

Ksju [112]

Answer:

the answer is a

Explan:

4 0

2 years ago