BIO-1407 Lecture 13 & 14

Which of the following is not a major chemical class of hormones?

• Amino acid-based hormones
• Steroids
• Carbohydrates
• Eicosanoids

Answer explanation

The main chemical classes of hormones are amino acid-based hormones, steroids, and eicosanoids. Carbohydrates are not a class of hormones.

How do most amino acid-based hormones exert their effects on target cells?

• By directly activating genes in the nucleus
• By binding to plasma membrane receptors and activating second messengers
• By diffusing through the plasma membrane and binding intracellular receptors
• By being stored in vesicles inside the target cell

Answer explanation

Most amino acid-based hormones cannot cross the plasma membrane and bind to receptors on the cell surface, triggering a second messenger system such as cyclic AMP.

A patient with hypersecretion of growth hormone during adulthood is most likely to develop:

• Acromegaly
• Pituitary dwarfism
• Addison’s disease
• Gigantism

Answer explanation

Hypersecretion of growth hormone in adults results in acromegaly, characterized by enlarged extremities.

If the thyroid gland is underactive, which of the following symptoms is most likely to occur?

• Rapid weight loss
• Increased heart rate
• Cold intolerance
• Excessive sweating

Answer explanation

Hypothyroidism (underactive thyroid) can cause cold intolerance, as well as fatigue and weight gain.

Tags

NGSS.HS-LS1-3

Which of the following is not considered a major endocrine gland but has discrete areas of endocrine tissue?

• Heart
• Pituitary gland
• Pancreas
• Skin

Answer explanation

The pituitary gland is a major endocrine gland; others listed are not primarily endocrine glands.

What determines whether a cell is a target cell for a specific hormone?

• The location of the cell in the body
• The presence of appropriate hormone receptors on the plasma membrane
• The number of mitochondria in the cell
• The size of the cell

Answer explanation

Only cells with the specific receptors for a hormone can respond; the presence of these receptors defines a target cell.

Tags

NGSS.HS-LS1-3

Which sequence best describes the action of a hormone using the cAMP second messenger system?

• Hormone → receptor → G protein → adenylate cyclase → cAMP
• Receptor → hormone → adenylate cyclase → G protein → cAMP
• Hormone → adenylate cyclase → receptor → cAMP → G protein
• Hormone → cAMP → receptor → G protein → adenylate cyclase

Answer explanation

Hormone binds to its receptor, which activates a G protein; G protein activates adenylate cyclase, converting ATP to cAMP.

A child is diagnosed with pituitary dwarfism. What is the underlying cause?

• Hyposecretion of insulin
• Hyposecretion of growth hormone
• Hypersecretion of thyroid hormone
• Hypersecretion of ACTH

Answer explanation

Pituitary dwarfism in children is due to hyposecretion of growth hormone.

Which hormone is produced by the posterior pituitary gland?

• Thyroid-stimulating hormone (TSH)
• Oxytocin
• Growth hormone (GH)
• Prolactin (PRL)

Answer explanation

The posterior pituitary stores and releases oxytocin and ADH.

Tags

NGSS.HS-LS1-3

Which hormone is produced by the heart?

• Erythropoietin
• Atrial natriuretic peptide (ANP)
• Melatonin
• Gastrin

Answer explanation

The heart produces ANP, which regulates blood pressure and fluid balance.