Which of the following represents the first line of defense to an intruding pathogen?

The correct answer is choice A. Golgi apparatus.

The Golgi apparatus is a membrane-bound organelle that is responsible for transporting, modifying, and packaging proteins and lipids into vesicles for delivery to targeted destinations.

Choice B is incorrect because mitochondria are responsible for energy production.

Choice C is incorrect because ribosomes are responsible for protein production.

Choice D is incorrect because the endoplasmic reticulum is responsible for lipid production and protein production, but not for modifying, sorting and packaging proteins and lipids.

These are the four nucleotide bases found in DNA1.

Choice B) Adenine, Thymidine, Cytidine, Guanine is incorrect because Thymidine and Cytidine are not nucleotide bases found in DNA.

Choice C) Adenosine, Thymine, Cytosine, Guanosine is incorrect because Adenosine and Guanosine are not nucleotide bases found in DNA.

Choice D) Adenosine, Thymidine, Cytidine, Guanosine is incorrect because Adenosine, Thymidine and Cytidine are not nucleotide bases found in DNA.

The correct answer is choice A. Orthopnea.

Orthopnea refers to a condition in which a patient experiences difficulty breathing while lying down, but their breathing improves when they sit up or stand.

Choice B, Hypoxia, is not the correct answer because it refers to a condition in which there is a lack of oxygen supply to the body’s tissues.

Choice C, Tachypnea, is not the correct answer because it refers to rapid breathing.

Choice D, Bradypnea, is not the correct answer because it refers to abnormally slow breathing.

Glycogen is the storage form of glucose in the human body.

It is a polysaccharide that is stored primarily in the liver and muscle tissue and can be broken down into glucose when the body needs energy.

Choice A is incorrect because starch is a storage form of glucose in plants, not in the human body.

Choice C is incorrect because fructose is a simple sugar, not a storage form of glucose.

Choice D is incorrect because cellulose is a structural carbohydrate found in plant cell walls, not a storage form of glucose in the human body.

The correct answer is choice B.

It decreases the activation energy required for the reaction.

A catalyst provides a new reaction pathway in which a lower activation energy is offered.

This allows more reactant molecules to collide with enough energy to surmount the smaller energy barrier, increasing the rate of reaction 2.

Choice A, It increases the activation energy required for the reaction, is not the correct answer because it describes the opposite effect of a catalyst.

Choice C, It has no effect on the activation energy required for the reaction, is not the correct answer because a catalyst does have an effect on activation energy.

Choice D, It increases the rate of reaction but has no effect on the activation energy, is not the correct answer because a catalyst increases the rate of reaction by decreasing the activation energy.

The plasma membrane is the organelle that encapsulates the contents of the cell and plays a vital role in regulating the movement of substances in and out of the cell.

It is a selectively permeable barrier that separates the internal environment of the cell from the external environment.

Choice A is incorrect because ribosomes are organelles involved in protein synthesis, not in regulating the movement of substances in and out of the cell.

Choice B is incorrect because the nucleus is an organelle that contains the cell’s genetic material, not in regulating the movement of substances in and out of the cell.

Choice C is incorrect because mitochondria are organelles involved in energy production, not in regulating the movement of substances in and out of the cell.

The correct answer is choice B.

Using a placebo group and a double-blind technique for giving the medications is the best way to ensure that the study is valid and reliable.

A placebo group helps control for the placebo effect, which can influence the results of a study.

A double-blind technique means that neither the patients nor the researchers know which medication is being given, reducing bias.

Choice A is not the best answer because while a large sample size and standardized procedure can increase reliability, they do not address validity.

Choice C is not the best answer because a matched-pairs design and crossover technique are useful for reducing variability but do not address validity.

Choice D is not the best answer because a convenience sample may not be representative and a pretest-posttest design does not control for extraneous variables.

Protons contribute to the positive charge of an atom.

Protons are subatomic particles with a positive charge found in the nucleus of an atom.

Choice B is incorrect because neutrons are neutral and do not have a charge. Choice C is incorrect because electrons have a negative charge.

Choice D is incorrect because nucleons refer to both protons and neutrons, but only protons contribute to the positive charge of an atom.

The correct answer is choice A.

Increased respiration rate to remove excess CO2.

The body regulates blood pH through several mechanisms, including chemical buffers, the respiratory system, and the urinary system.

The respiratory system can adjust blood pH by changing the rate of respiration to remove or retain CO2.

When there is excess acid in the blood, the respiratory rate increases to remove more CO2, which helps to raise blood pH.

Choice B is incorrect because decreasing the respiration rate would retain CO2, which would lower blood pH.

Choice C is incorrect because increased water intake would not directly affect blood pH levels.

Choice D is incorrect because decreased water intake would not directly affect blood pH levels.

The correct answer is choice A.

The shape and surface area of the object.

The terminal velocity of an object falling through a fluid is affected by several factors, including its mass and shape.

Objects with large surface areas will often experience a large amount of air resistance when they move.

Choice B is incorrect because the volume of the object does not affect its terminal velocity.

Choice C is incorrect because the acceleration and momentum of the object do not affect its terminal velocity.

Choice D is incorrect because the height and distance of the fall do not affect the terminal velocity of a falling object.