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Biology
Which hormone, released by the posterior pituitary gland, acts directly on the kidneys to increase water reabsorption and concentrate the urine?
A
Aldosterone
B
Antidiuretic hormone (ADH)
C
Insulin
D
Cortisol
Correct Answer
B
Biology
What complex carbohydrate do plants use as their primary energy storage molecule, consisting of a long chain of glucose units?
A
Cellulose
B
Glycogen
C
Starch
D
Chitin
Correct Answer
C
Biology
According to the sliding filament theory, which structural unit of a myofibril serves as the basic functional unit of muscle contraction?
A
Sarcomere
B
Sarcolemma
C
Sarcoplasm
D
Myosin head
Correct Answer
A
Biology
What type of directional growth response occurs when a plant grows or bends toward a light source?
A
Thigmotropism
B
Geotropism
C
Phototropism
D
Hydrotropism
Correct Answer
C
Biology
Which powerful digestive enzyme is activated in the stomach to begin the chemical breakdown of proteins into smaller peptides?
A
Amylase
B
Lipase
C
Trypsin
D
Pepsin
Correct Answer
D
Biology
What term describes the random fluctuation of allele frequencies in a population over time, which typically has a much larger impact on smaller populations?
A
Gene flow
B
Natural selection
C
Genetic drift
D
Artificial selection
Correct Answer
C
Biology
Which class of proteins acts as the primary regulators of the cell cycle, controlling a cell's progression through various checkpoints?
A
Histones
B
Cyclins
C
Immunoglobulins
D
Actins
Correct Answer
B
Biology
What type of mutation occurs when a single nucleotide base is substituted, inserted, or deleted from a DNA sequence?
A
Chromosomal mutation
B
Point mutation
C
Frameshift inversion
D
Polyploidy
Correct Answer
B
Biology
What is the name of the outermost, non-vascularized layer of the human skin?
A
Dermis
B
Hypodermis
C
Epidermis
D
Subcutaneous layer
Correct Answer
C
Biology
What iron-rich protein molecule is found in red blood cells that allows them to bind reversibly and transport oxygen?
A
Hemoglobin
B
Myoglobin
C
Hemocyanin
D
Keratin
Correct Answer
A