If a dna sequence is altered from tagctga to tagtga, what kind of mutation has occurred?

Is natural selection the only means of evolution? Explain.

Sunny_sXe [5.5K]

Answer:

Much change is due to random genetic drift rather than positive selection. Some are harmful and are likely to be eliminated by natural selection – by death of the embryo, for instance. ...

3 0

2 years ago

Neurons in the parasympathetic pathway use which neurotransmitters?

Kay [80]

<h2>Acetylcholine</h2>

Explanation:

Acetylcholine is a chemical that is found between the nerve synapses, or gaps, between nerve cells. When activated, it causes the contraction of skeletal muscles and activates glandular functions in the endocrine system. Think of acetylcholine as a mailperson; residents cannot receive their mail until he or she comes and delivers it to the mailbox. Like mailpersons who deliver the mail and move on to the next house, acetylcholine acts quickly and does not hang around. As a result, acetylcholine is rapidly broken down by another chemical substance called cholinesterase.
Acetylcholine was the first neurotransmitter scientists discovered, as well as the most abundant neurotransmitter in the body. A neurotransmitter is a chemical that is released by a neuron, or nerve cell, that sends a signal to another neuron across a synapse. The neurotransmitter binds to receptors to affect how the signal is received. The purpose of the neurotransmitter is to either amplify or inhibit the signals sent between the neurons.
Acetylcholine plays an important role in the signal of muscle movement, sensation of pain, learning and memory formation, the regulation of the endocrine system and rapid eye movement (REM) sleep cycles.

5 0

3 years ago

Sea Rocket Plant siblings Lif planted next to each other

stiks02 [169]

I believe the answer would be B.

8 0

3 years ago

In the lumen of the proximal tubule, Na concentration is ________ the Na concentration inside the cells of the tubule wall.

nydimaria [60]

Answer:

The correct answer is - higher than

Explanation:

In the lumen of the proximal tubule of the kidney, most of the solutes are absorbed in the form of sodium. There is a gradient of sodium ions which allows the absorption of the solutes from the lumen into the cell.

It is due to the solute or Na concentration is higher in the lumen than Na concentration inside the cells of the tubule wall. So movement of the solutes is due to the concentration gradient.

3 0

2 years ago

This sample is naturally occurring, inorganic, solid, has a square crystal structure, and a definite chemical composition (NaCl)

Alika [10]

Answer:

A Mineral is defined as an inorganic, naturally occurring, homogenoussolid, with a definite chemical composition, and ordered (crystalline) atomic structures.

Explanation:

Inorganic: Involving neither organic life nor the products created from or by organic life.

Naturally Occurring: Must be formed by natural processes, meaning a mineral cannot be manmade, manufactured, or created in a laboratory.

Homogeneous Solid: A mineral must be chemically and physically uniform down to the atomic level.

This homogeneity means that the mineral will have absolutely predictable physical properties

including hardness, density, and streak.

Definite Chemical Composition means that all occurrences of that mineral have a chemical

composition that varies within a specific limited range and the atoms that make up the mineral must

occur in specific ratios.

Ordered Atomic structure (Crystalline): The atoms in a mineral are arranged in a systematic and

repeating pattern. Glasses such as obsidian, which are disordered solids, liquids (e.g., water,

mercury), and gases (e.g., air) do not have a crystalline structure and are therefore not minerals.

5 0

2 years ago