ATI TEAS Exam Science Review Updated Study
Guide Questions and Answers (2026) | Focused
Revision Pack | Grade A+
Which of the following cell types provides a waterproofing function for the outer
layers of skin?
A. Melanocytes
B. Keratinocytes
C. Merkel cells
D. Langerhans cells -✓✓B. Keratinocytes
Keratinocytes contain the protein keratin. They are produced in the epidermis and
migrate upwards. The tight junctions between cells prevent water entry. They
eventually form a layer of dead cells on the skin surface, which produces a
waterproofing effect.
A person is suddenly frightened. Which of the following reactions occurs next?
A. Liver cells absorb glucose from the blood stream.
B. Blood vessels supplying skeletal muscles constrict.
C. Blood vessels supplying the intestines dilate.
D. Liver cells release glucose into the blood stream. -✓✓D. Liver cells release
glucose into the blood stream.
Epinephrine causes liver cells to break down glycogen, which causes an increase in
sugar in the blood stream.
Kidneys remove which of the following from the blood?
A. Platelets
B. Salts
C. Oxygen
D. Fat -✓✓B. Salts
Salts are removed by the kidneys.
, Which of the following structures within a human cell is responsible for recycling
the materials no longer functional or needed within the cell?
A. Ribosome
B. Lysosome
C. Mitochondrion
D. Nucleolus -✓✓B. Lysosome
Lysosomes are specialized vacuoles containing digestive enzymes.
Which of the following are sesamoid bones?
A. Phalanges
B. Patellae
C. Scapulae
D. Metatarsals -✓✓B. Patellae
Patellae are sesamoid bones, which develop in response to strain. Patellae are also
considered short bones.
Which of the following chemical compounds prevents the lungs from collapsing?
A. Mucus
B. Surfactant
C. Enzymes
D. Buffers -✓✓B. Surfactant
Surfactants are lipopolysaccharides that have a hydrophobic and hydrophilic layer.
They keep the lungs inflated.
The use of an electron would most benefit the study of
A. the structure of atoms.
B. the structure of cellular organelles.
C. the structure of skeletal joints.
D. chemical bones in molecules. -✓✓B. the structure of cellular organelles
Electron microscopy has significantly improved the ability to see and understand
the workings of these organelles because electron wavelengths are short enough to
Guide Questions and Answers (2026) | Focused
Revision Pack | Grade A+
Which of the following cell types provides a waterproofing function for the outer
layers of skin?
A. Melanocytes
B. Keratinocytes
C. Merkel cells
D. Langerhans cells -✓✓B. Keratinocytes
Keratinocytes contain the protein keratin. They are produced in the epidermis and
migrate upwards. The tight junctions between cells prevent water entry. They
eventually form a layer of dead cells on the skin surface, which produces a
waterproofing effect.
A person is suddenly frightened. Which of the following reactions occurs next?
A. Liver cells absorb glucose from the blood stream.
B. Blood vessels supplying skeletal muscles constrict.
C. Blood vessels supplying the intestines dilate.
D. Liver cells release glucose into the blood stream. -✓✓D. Liver cells release
glucose into the blood stream.
Epinephrine causes liver cells to break down glycogen, which causes an increase in
sugar in the blood stream.
Kidneys remove which of the following from the blood?
A. Platelets
B. Salts
C. Oxygen
D. Fat -✓✓B. Salts
Salts are removed by the kidneys.
, Which of the following structures within a human cell is responsible for recycling
the materials no longer functional or needed within the cell?
A. Ribosome
B. Lysosome
C. Mitochondrion
D. Nucleolus -✓✓B. Lysosome
Lysosomes are specialized vacuoles containing digestive enzymes.
Which of the following are sesamoid bones?
A. Phalanges
B. Patellae
C. Scapulae
D. Metatarsals -✓✓B. Patellae
Patellae are sesamoid bones, which develop in response to strain. Patellae are also
considered short bones.
Which of the following chemical compounds prevents the lungs from collapsing?
A. Mucus
B. Surfactant
C. Enzymes
D. Buffers -✓✓B. Surfactant
Surfactants are lipopolysaccharides that have a hydrophobic and hydrophilic layer.
They keep the lungs inflated.
The use of an electron would most benefit the study of
A. the structure of atoms.
B. the structure of cellular organelles.
C. the structure of skeletal joints.
D. chemical bones in molecules. -✓✓B. the structure of cellular organelles
Electron microscopy has significantly improved the ability to see and understand
the workings of these organelles because electron wavelengths are short enough to
