BIOD 121 Nutrition Exams (Modules 1–6 + Final) | Portage
Learning 2025 | Actual Questions & Verified Answers PDF
,COMPREHENSIVE NUTRITION AND DIGESTION EXAM
Which type of diffusion can move substances down concentration gradients
utilizing a transporter?
A) Passive diffusion
B) Osmosis
C) Facilitated diffusion
D) Active transport
Correct Answer: C) Facilitated diffusion
Explanation: Facilitated diffusion uses transporter proteins to move substances
down their concentration gradient without energy expenditure. Unlike passive
diffusion, which moves directly through the membrane, facilitated diffusion
requires carrier proteins or channel proteins to help substances cross the
membrane while still moving from high to low concentration.
Which type of diffusion can move nutrients against the concentration from an
area of low concentration to an area of high?
,A) Passive diffusion
B) Active transport
C) Facilitated diffusion
D) Osmosis
Correct Answer: B) Active transport
Explanation: Active transport requires energy (ATP) to move substances against
their concentration gradient—from areas of low concentration to areas of high
concentration. This is different from passive diffusion and facilitated diffusion,
which only move substances down their concentration gradients without energy
input.
Which type of diffusion can move substances easily in and out of cells down
concentration gradients through the cell membrane?
A) Active transport
B) Facilitated diffusion
C) Passive diffusion
D) Osmosis
Correct Answer: C) Passive diffusion
Explanation: Passive diffusion is the simplest form of diffusion where substances
move directly through the cell membrane down their concentration gradient
without the need for transporters or energy. Small, nonpolar molecules like
oxygen and carbon dioxide typically use this method.
passageway for food
A) Stomach
B) Esophagus
C) Small intestine
D) Trachea
Correct Answer: B) Esophagus
, Explanation: The esophagus is a muscular tube that connects the pharynx to the
stomach, serving as the passageway for food and liquids after swallowing. It uses
peristaltic contractions to move food toward the stomach.
hold volume of food and mechanically and chemically digest it
A) Large intestine
B) Esophagus
C) Stomach
D) Rectum
Correct Answer: C) Stomach
Explanation: The stomach serves as a storage reservoir for food while performing
both mechanical digestion (through churning and mixing) and chemical digestion
(through gastric juices containing hydrochloric acid and enzymes like pepsin that
break down proteins).
site of digestion and absorption
A) Stomach
B) Large intestine
C) Small intestine
D) Esophagus
Correct Answer: C) Small intestine
Explanation: The small intestine is the primary site where most chemical digestion
occurs and where the vast majority of nutrient absorption takes place. Its
extensive surface area, created by villi and microvilli, maximizes absorption of
digested nutrients into the bloodstream.
reabsorbs water and some vitamins
A) Small intestine
B) Stomach
Learning 2025 | Actual Questions & Verified Answers PDF
,COMPREHENSIVE NUTRITION AND DIGESTION EXAM
Which type of diffusion can move substances down concentration gradients
utilizing a transporter?
A) Passive diffusion
B) Osmosis
C) Facilitated diffusion
D) Active transport
Correct Answer: C) Facilitated diffusion
Explanation: Facilitated diffusion uses transporter proteins to move substances
down their concentration gradient without energy expenditure. Unlike passive
diffusion, which moves directly through the membrane, facilitated diffusion
requires carrier proteins or channel proteins to help substances cross the
membrane while still moving from high to low concentration.
Which type of diffusion can move nutrients against the concentration from an
area of low concentration to an area of high?
,A) Passive diffusion
B) Active transport
C) Facilitated diffusion
D) Osmosis
Correct Answer: B) Active transport
Explanation: Active transport requires energy (ATP) to move substances against
their concentration gradient—from areas of low concentration to areas of high
concentration. This is different from passive diffusion and facilitated diffusion,
which only move substances down their concentration gradients without energy
input.
Which type of diffusion can move substances easily in and out of cells down
concentration gradients through the cell membrane?
A) Active transport
B) Facilitated diffusion
C) Passive diffusion
D) Osmosis
Correct Answer: C) Passive diffusion
Explanation: Passive diffusion is the simplest form of diffusion where substances
move directly through the cell membrane down their concentration gradient
without the need for transporters or energy. Small, nonpolar molecules like
oxygen and carbon dioxide typically use this method.
passageway for food
A) Stomach
B) Esophagus
C) Small intestine
D) Trachea
Correct Answer: B) Esophagus
, Explanation: The esophagus is a muscular tube that connects the pharynx to the
stomach, serving as the passageway for food and liquids after swallowing. It uses
peristaltic contractions to move food toward the stomach.
hold volume of food and mechanically and chemically digest it
A) Large intestine
B) Esophagus
C) Stomach
D) Rectum
Correct Answer: C) Stomach
Explanation: The stomach serves as a storage reservoir for food while performing
both mechanical digestion (through churning and mixing) and chemical digestion
(through gastric juices containing hydrochloric acid and enzymes like pepsin that
break down proteins).
site of digestion and absorption
A) Stomach
B) Large intestine
C) Small intestine
D) Esophagus
Correct Answer: C) Small intestine
Explanation: The small intestine is the primary site where most chemical digestion
occurs and where the vast majority of nutrient absorption takes place. Its
extensive surface area, created by villi and microvilli, maximizes absorption of
digested nutrients into the bloodstream.
reabsorbs water and some vitamins
A) Small intestine
B) Stomach
