decomposers in an ecosystem play a vital role by

ATI TEAS 7

TEAS 7 science quizlet

1. Decomposers in an ecosystem play a vital role by:

A. Photosynthesizing and producing organic matter
B. Breaking down dead organisms and returning nutrients to the environment
C. Preying on herbivores and controlling their populations
D. Fixing nitrogen from the atmosphere and making it available to plants

Correct answer: B

Rationale: Decomposers are organisms that break down dead organic matter, such as dead plants and animals, into simpler substances. By doing so, they help to recycle nutrients back into the environment, making them available for other organisms to use. This process is essential for the functioning of ecosystems, as it ensures that nutrients are not lost but instead are continuously cycled through the ecosystem. Photosynthesis (option A) is the process by which plants and some other organisms convert light energy into chemical energy in the form of glucose, and it is not a role of decomposers. Preying on herbivores (option C) is a role typically carried out by predators, not decomposers. Fixing nitrogen from the atmosphere (option D) is a process carried out by nitrogen-fixing bacteria, not decomposers.

2. What does the concept of punctuated equilibrium suggest?

A. Evolution occurs gradually through the continuous accumulation of small changes over long periods.
B. Evolution is characterized by long periods of relative stasis punctuated by rapid bursts of evolutionary change.
C. The fossil record is a complete and accurate representation of all past life forms.
D. Natural selection primarily favors extreme phenotypes within a population.

Correct answer: B

Rationale: Punctuated equilibrium suggests that evolution is characterized by long periods of relative stasis punctuated by rapid bursts of evolutionary change. This concept, proposed by Stephen Jay Gould and Niles Eldredge, implies that species remain relatively unchanged for extended periods, followed by sudden bursts of rapid evolution. Option A describes the gradualism model, which is different from punctuated equilibrium. Option C is inaccurate as the fossil record is incomplete and biased. Option D is unrelated to the concept of punctuated equilibrium.

3. Where is the major site for nutrient absorption in the digestive system?

A. Mouth
B. Stomach
C. Small intestine
D. Large intestine

Correct answer: C

Rationale: The small intestine is recognized as the major site for nutrient absorption in the digestive system. It plays a crucial role in the digestion and absorption of nutrients from food. The small intestine's villi and microvilli provide a large surface area specialized for absorbing nutrients like carbohydrates, proteins, fats, vitamins, and minerals. This efficient absorption process is essential for supplying the body with the necessary nutrients for energy production, growth, and overall functioning. The mouth is primarily involved in the initial stages of digestion through mechanical and chemical breakdown of food. The stomach aids in further mechanical and chemical digestion but is not the primary site for nutrient absorption. The large intestine's main function is to absorb water and electrolytes, not nutrients.

4. Which organelle is responsible for producing energy in the cell?

A. Nucleus
B. Mitochondria
C. Golgi apparatus
D. Ribosome

Correct answer: B

Rationale: The correct answer is B: Mitochondria. Mitochondria are known as the powerhouse of the cell and are responsible for producing energy in the form of ATP through the process of cellular respiration. The other organelles listed, such as the nucleus, Golgi apparatus, and ribosome, have different functions within the cell and are not directly involved in energy production. The nucleus is responsible for storing genetic material and controlling cell activities. The Golgi apparatus is involved in modifying, sorting, and packaging proteins. Ribosomes are responsible for protein synthesis.

5. Which of the following is a functional group commonly found in alcohols?

A. Carbonyl
B. Hydroxyl
C. Amine
D. Ester

Correct answer: B

Rationale: The hydroxyl functional group (OH) is commonly found in alcohols, giving them their characteristic properties. Alcohols are organic compounds that contain a hydroxyl group bonded to a carbon atom. The other choices, carbonyl, amine, and ester, are associated with different functional groups commonly found in other types of organic compounds. Carbonyl groups consist of a carbon atom double-bonded to an oxygen atom. Amines contain a nitrogen atom bonded to hydrogen atoms. Esters consist of a carbonyl group bonded to an alkoxyl group. Therefore, the correct answer is 'Hydroxyl (B),' as it specifically relates to the functional group present in alcohols, distinguishing it from the other options.