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Question:

A nerve impulse is transmitted through your nervous system primarily by `____`.

A An electric potential

explanation

Nerve impulses are transmitted in the nervous system primarily through the means of electric potentials, which are generated by a change in the balance of sodium, potassium, and calcium ions in the nerve cell.

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What is the molecular weight of the compound C2H5OH?

46

To find the molecular weight of a compound, we add up the masses of each individual element. Carbon has an atomic mass of 12, hydrogen is 1, and oxygen is 16. Thus, 12(2) + 1(5) + 16 + 1= 46 atomic mass units.

The tilt of the Earth's rotational axis toward or away from the sun causes ____.

Seasons

Because of Earth's axial tilt, different areas of Earth point toward or away from the Sun at different times of the year. In June, the North Pole is tilted toward the Sun and the Northern Hemisphere receives more of the Sun's direct rays. At the same time, the South Pole points away from the Sun, creating winter in the Southern Hemisphere during the months of June, July and August.

Sound waves will travel the fastest in a medium that is ____.

The most dense

The speed of sound is directly proportional to the density of the material through which it travels, with the speed being faster in more dense materials. For example, the speed of sound in air is 343 m/s, but the speed of sound in water, a more dense substance, is 1,463 m/s.

Animals that feed exclusively on plants are called ____.

Primary consumers

In an ecological food chain, primary producers are those that photosynthesize and utilize sunlight as their energy source; this trophic level is almost entirely made up of plants. Primary consumers attain their energy from primary producers; cows are primary consumers as they survive solely on grass. Secondary consumers, such as wolves and eagles, feed upon primary consumers, and tertiary consumers, like great white sharks, feed upon primary and secondary consumers.

Which of the following is a characteristic of the tundra ecological biome?

Landscape dominated by shrubs and short trees

The tundra environment is characterized by very low year-round temperatures, low to moderate rainfall, and shrubs and short trees. Countries that are predominantly tundra include Canada and Russia.

Which atmospheric layer contains the ozone layer?

Stratosphere

The troposphere is the lowest atmospheric layer, and contains water vapor and suspended particles, and is where weather takes place. The stratosphere is above the troposphere, and is the region that contains the ozone layer, which absorbs most of the Sun's ultraviolet radiation. The mesosphere is the next highest layer followed by the thermosphere and exosphere.

The nucleus of an atom is composed of ____.

Protons and neutrons

The nucleus of an atom is composed of protons and neutrons. The electrons orbit the nucleus in electron orbitals.

Craig ran 2.5 miles on his afternoon run. How many feet did he run?

13200

There are 5,280 feet in a mile, meaning that 2.5 miles is 13,200 feet.

Which of the following time periods is the longest?

Eon

In the geologic time scale, an eon encompasses 500 million years, whereas an era encompasses 100-150 million years. Periods and ages are much shorter, in the range of 1-10 million years.

As light passes through a substance, the incident angle changes, meaning the light’s entering angle is different than its exiting angle. This is an example of ____.

Refraction

Refraction is defined as the change in direction of light (or a wave) as it passes through a material. Diffraction is wave interference by a medium which causes scattering of the light.

One of the primary characteristics of a bacteria is its:

Lack of a nuclear membrane

All bacteria are prokaryotes, which is a classification of organisms that do not have nuclear membranes. Many other cells that are not bacteria are able to move or consume glucose, and all cells have a cell membrane!

Which of the following statements about the Earth is true?

The mantle makes up the largest percentage of the Earth’s volume

The mantle is the largest segment of the Earth’s structure, and takes up the most space by volume. The crust is interestingly not the only solid part of Earth, the inner core is also solid, and is believed to be made up of a mixture of iron and nickel.

The energy of an object resulting solely from motion is ____.

Kinetic energy

Kinetic energy is the energy which an object possesses because of its motion. Potential energy is the stored energy in an object due to its position or its configuration. Thermal energy relates an object’s energy to its temperature. The mechanical energy of an object is the sum of its kinetic and potential energy.

If one tectonic plate slides under another, the process is known as ____.

Subduction

The process of one tectonic plate sliding under another is known as subduction. When neither plate moves under the other, the result is compression, and the two colliding plates will form mountains (a process known as orogenesis).