NLN PAX Practice Test Science
Questions & Answers 2024/2025
An organism with chloroplast in its cell is probably a - ANSWERSautotroph
autotrophs - ANSWERSare organisms that produce their own food from inorganic substances, plants are
autotrophs
heterotrophs - ANSWERSobtain their food by consuming plants or other animals. They are also referred
to as consumers.
Primary consumers may be herbivores
herbivores - ANSWERSplant eaters
omnivores - ANSWERSplant and meat eaters
Secondary consumers - ANSWERSare carnivores, meat eaters, or omnivores that eat herbivores.
Tertiary consumers are carnivores that eat - ANSWERSother carnivores or omnivores.
What property of water allows someone to fill a glass slightly above the rim without the water flowing
over? - ANSWERSsurface tension
Water molecules are polar. This is due to the fact that oxygen draws the electrons in the molecule
toward itself. Thus, there is a negative charge surrounding the oxygen and a positive charge around the
hydrogen. The unbalanced charges cause the water molecules to cluster, and this gives the water the
properties called surface tension. Surface tension is the the attraction between molecules at the surface
of a liquid, which allows a glass to be filled above the rim without the water flowing over.
The gap between the neurons are called - ANSWERSsynapses
,Which group of chemicals are not normally found in most living things? - ANSWERSsilicates
Carbohydrates, proteins and nucleic acids (RNA and DNA) are all very important chemicals in living
things.
Silicates examples are in sand and glass
The alimentary canal is associated with the - ANSWERSthe whole passage along which food passes
through the body from mouth to anus. It includes the esophagus, stomach, and intestines.
digestive tract
The numerous villi in the small intestine serve to - ANSWERSprovide greater surface area for absorption
As light passes obliquely from air to water, it is bent. The bending is called - ANSWERSrefraction
refraction is the bending of light as it passes obliquely from one medium to another, in this case from air
to water. The speed of light wave changes changes when it changes media. When the light wave enters
the second medium at an oblique angle, it changes direction; the light wave is bent.
diffraction - ANSWERSrefers to the spreading of light waves as they pass through a narrow opening
reflection - ANSWERSoccurs when light bounces off an object.
dispersion - ANSWERSoccurs when light is separated into its spectrum
Which of the following organelles is not involved in protein synthesis? - ANSWERSmitochondrion
To be absorbed by cells, proteins must be changed into - ANSWERSamino acids
,A neuron that transmits impulses from the receptors to the spinal cord is called - ANSWERSa sensory
neuron
Potential energy can be thought of a function of height. Since total energy is always conserved, the
kinetic energy is at its maximum when the potential is at its minimum. - ANSWERSor at the bottom of
the incline.
Which group of organisms can helps prevent the accumulation of organic wastes in nature? -
ANSWERSmosses is an algae
the correct answer is bacteria = bacteria comprise the decomposer portion of the food chain. They are
responsible for recycling organic material into inorganic material that plants can use to undergo
photosynthesis.
As the eardrum is made to vibrate more rapidly, the sound is perceived as - ANSWERShigher in pitch
high pitch sounds are heard when the receptor cells closer to the oval window are stimulated, and low-
pitch sounds result from the stimulation of the cells that are farther down the cochlea. The more rapid
the vibration is, the higher the pitch
In a field of pure white asters, a grower noticed a single blue aster. How could the grower test whether
this change affected the gamete-producing cells of the plant? - ANSWERSself-pollinate the flower, and
plant the resulting seeds.
Self pollination would allow the plant to produce gametes sperm and eggs that would unite and form
seeds. Observing the color of the plants from these seeds would allow the planter to determine whether
this change occurred at the level of the gametes.
A human egg will develop into a female if it is fertilized by a sperm containing - ANSWERSXX
chromosome
XY - male`
, In a food chain involving grass, grasshoppers, birds, and mammals, the original source of energy is -
ANSWERSsunlight
Which of the following is an neutralization reaction?
H2CO3 + Ca(OH)2 ---> 2H2O + CaCO3
Is an reaction between an acid (carbonic acid) and a base [Ca(OH)2] to form water and a salt. -
ANSWERSA reaction that removes essentially all H+ and OH-
In the context of a chemical reaction the term neutralization is used for a reaction between an acid and a
base
acid + base → salt + water
Acids are ionic compounds ( a compound with a positive or negative charge) that break apart in water to
form a hydrogen ion (H+).
Example: HCl (Hydrochloric acid) in water
*Bases are ionic compounds that break apart to form a negatively charged hydroxide ion (OH-) in water.
Example: NaOH (Sodium Hydroxide-a strong base) in water
When oxygen goes from air in the lungs into the blood, it does so by - ANSWERSdiffusion
Which of the following organs controls the amount of calcium in the blood?
parathyroid - ANSWERSThey produce parathyroid hormone. Parathyroid hormone (PTH, parathormone)
works antagonistically with calcitonin, which is produced in the thyroid gland. When calcium levels in the
blood are low, PTH causes bone cells to break down and release calcium. When calcium levels are high,
calcitonin causes calcium to deposit onto the bones.
pituitary gland - ANSWERSlocated under the brain
Questions & Answers 2024/2025
An organism with chloroplast in its cell is probably a - ANSWERSautotroph
autotrophs - ANSWERSare organisms that produce their own food from inorganic substances, plants are
autotrophs
heterotrophs - ANSWERSobtain their food by consuming plants or other animals. They are also referred
to as consumers.
Primary consumers may be herbivores
herbivores - ANSWERSplant eaters
omnivores - ANSWERSplant and meat eaters
Secondary consumers - ANSWERSare carnivores, meat eaters, or omnivores that eat herbivores.
Tertiary consumers are carnivores that eat - ANSWERSother carnivores or omnivores.
What property of water allows someone to fill a glass slightly above the rim without the water flowing
over? - ANSWERSsurface tension
Water molecules are polar. This is due to the fact that oxygen draws the electrons in the molecule
toward itself. Thus, there is a negative charge surrounding the oxygen and a positive charge around the
hydrogen. The unbalanced charges cause the water molecules to cluster, and this gives the water the
properties called surface tension. Surface tension is the the attraction between molecules at the surface
of a liquid, which allows a glass to be filled above the rim without the water flowing over.
The gap between the neurons are called - ANSWERSsynapses
,Which group of chemicals are not normally found in most living things? - ANSWERSsilicates
Carbohydrates, proteins and nucleic acids (RNA and DNA) are all very important chemicals in living
things.
Silicates examples are in sand and glass
The alimentary canal is associated with the - ANSWERSthe whole passage along which food passes
through the body from mouth to anus. It includes the esophagus, stomach, and intestines.
digestive tract
The numerous villi in the small intestine serve to - ANSWERSprovide greater surface area for absorption
As light passes obliquely from air to water, it is bent. The bending is called - ANSWERSrefraction
refraction is the bending of light as it passes obliquely from one medium to another, in this case from air
to water. The speed of light wave changes changes when it changes media. When the light wave enters
the second medium at an oblique angle, it changes direction; the light wave is bent.
diffraction - ANSWERSrefers to the spreading of light waves as they pass through a narrow opening
reflection - ANSWERSoccurs when light bounces off an object.
dispersion - ANSWERSoccurs when light is separated into its spectrum
Which of the following organelles is not involved in protein synthesis? - ANSWERSmitochondrion
To be absorbed by cells, proteins must be changed into - ANSWERSamino acids
,A neuron that transmits impulses from the receptors to the spinal cord is called - ANSWERSa sensory
neuron
Potential energy can be thought of a function of height. Since total energy is always conserved, the
kinetic energy is at its maximum when the potential is at its minimum. - ANSWERSor at the bottom of
the incline.
Which group of organisms can helps prevent the accumulation of organic wastes in nature? -
ANSWERSmosses is an algae
the correct answer is bacteria = bacteria comprise the decomposer portion of the food chain. They are
responsible for recycling organic material into inorganic material that plants can use to undergo
photosynthesis.
As the eardrum is made to vibrate more rapidly, the sound is perceived as - ANSWERShigher in pitch
high pitch sounds are heard when the receptor cells closer to the oval window are stimulated, and low-
pitch sounds result from the stimulation of the cells that are farther down the cochlea. The more rapid
the vibration is, the higher the pitch
In a field of pure white asters, a grower noticed a single blue aster. How could the grower test whether
this change affected the gamete-producing cells of the plant? - ANSWERSself-pollinate the flower, and
plant the resulting seeds.
Self pollination would allow the plant to produce gametes sperm and eggs that would unite and form
seeds. Observing the color of the plants from these seeds would allow the planter to determine whether
this change occurred at the level of the gametes.
A human egg will develop into a female if it is fertilized by a sperm containing - ANSWERSXX
chromosome
XY - male`
, In a food chain involving grass, grasshoppers, birds, and mammals, the original source of energy is -
ANSWERSsunlight
Which of the following is an neutralization reaction?
H2CO3 + Ca(OH)2 ---> 2H2O + CaCO3
Is an reaction between an acid (carbonic acid) and a base [Ca(OH)2] to form water and a salt. -
ANSWERSA reaction that removes essentially all H+ and OH-
In the context of a chemical reaction the term neutralization is used for a reaction between an acid and a
base
acid + base → salt + water
Acids are ionic compounds ( a compound with a positive or negative charge) that break apart in water to
form a hydrogen ion (H+).
Example: HCl (Hydrochloric acid) in water
*Bases are ionic compounds that break apart to form a negatively charged hydroxide ion (OH-) in water.
Example: NaOH (Sodium Hydroxide-a strong base) in water
When oxygen goes from air in the lungs into the blood, it does so by - ANSWERSdiffusion
Which of the following organs controls the amount of calcium in the blood?
parathyroid - ANSWERSThey produce parathyroid hormone. Parathyroid hormone (PTH, parathormone)
works antagonistically with calcitonin, which is produced in the thyroid gland. When calcium levels in the
blood are low, PTH causes bone cells to break down and release calcium. When calcium levels are high,
calcitonin causes calcium to deposit onto the bones.
pituitary gland - ANSWERSlocated under the brain
