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Which of the following is the approximate threshold value for mammalian neurons?

A. +35 mV

B. -55 mV

C. 0 mV

D. -80 mV

Answer Explanation:

The approximate threshold value for mammalian neurons is -55mV.

Therefore, the Correct Answer is B.

More Questions on TEAS 7 Science

  • Q #1: #OF FILTERS MASS (g) TERMINAL VELOCITY (m/s) 1 1.01 1.74 2 1.99 2.48 3 3.02 3.04 4 4.0 3.50 5 5.01 3.80 A group of students perform an experiment to test terminal velocity, which is the greatest speed obtained by a falling object. The students dropped different numbers of coffee filters and measured the resulting terminal velocity. Which of the following conclusions is supported by the data in the following data table?

    A. Terminal velocity is when the force of gravity is equal to air resistance.

    B. Heavier objects take more time to reach terminal velocity.

    C. The greater the number of filters, the smaller the terminal velocity

    D. Heavier objects fall faster than lighter objects.

    Answer Explanation

    Terminal velocity is the maximum speed achieved by an object freely falling through a gas or liquid. At terminal velocity, the forces acting on the object are balanced so it is no longer accelerating. Terminal velocity is achieved when the force of gravity is equal to air resistance. From the data table you provided, we can see that as the mass of the coffee filters increases, so does the terminal velocity. This means that heavier objects fall faster than lighter objects. Therefore, conclusion D is supported by the data in the table.

     

  • Q #2: Which of the following indicates the function of sodium bicarbonate released by the pancreas?

    A. Sodium bicarbonate inhibits peristalsis.

    B. Sodium bicarbonate stimulates the pyloric sphincter.

    C. Sodium bicarbonate is a protease that digests carbohydrates.

    D. Sodium bicarbonate neutralizes the acidity of chyme.

    Answer Explanation

    The pancreas releases sodium bicarbonate into the duodenum, the first part of the small intestine. The main function of sodium bicarbonate is to neutralize the acidity of chyme, the semi-digested food that comes from the stomach. By doing so, sodium bicarbonate creates a more alkaline environment that is suitable for the action of pancreatic enzymes. Sodium bicarbonate does not affect peristalsis, the rhythmic contraction of the intestinal muscles, nor does it stimulate the pyloric sphincter, the valve that controls the passage of food from the stomach to the duodenum. Sodium bicarbonate is not a protease, an enzyme that digests proteins, nor does it digest carbohydrates. 

     

  • Q #3: In a hypertonic solution, water flows through aquaporins embedded in the plasma membrane of the cell. This type of transport is best known as which of the following?

    A. Osmosis

    B. Diffusion

    C. Facilitated diffusion

    D. Active transport

    Answer Explanation

    One of the ways that cells regulate their water balance is by adjusting to different solute concentrations in their environment. When a cell is placed in a solution that has a higher concentration of solutes than the cell itself, the solution is called hypertonic. In this case, water will tend to move out of the cell through special channels called aquaporins, which are embedded in the plasma membrane. This movement of water across a selectively permeable membrane is a type of passive transport called osmosis. Osmosis does not require any energy input from the cell, unlike other forms of transport such as diffusion, facilitated diffusion, or active transport.