the primary source of energy entering most ecosystems is

ATI TEAS 7

ati teas 7 science

1. What is the primary source of energy entering most ecosystems?

A. Chemical energy stored in bonds
B. Thermal energy from the Earth's core
C. Light energy from the sun
D. Kinetic energy from wind and water

Correct answer: C

Rationale: In most ecosystems, the primary source of energy is sunlight. This energy is captured by plants and other photosynthetic organisms through the process of photosynthesis. These organisms convert light energy into chemical energy stored in the bonds of organic molecules, such as glucose. This stored chemical energy is then passed on to other organisms in the ecosystem through the food chain, making sunlight the fundamental source of energy for most ecosystems. Thermal energy from the Earth's core (option B) is not a primary source of energy for ecosystems, as it is not readily accessible to most organisms. Kinetic energy from wind and water (option D) can play a role in some ecosystems, but it is not the primary source of energy. Chemical energy stored in bonds (option A) is a form of energy that is ultimately derived from the sun through photosynthesis, making it a product of the primary energy source rather than the primary source itself.

2. Muscles that work in opposition to each other, producing opposing movements, are called:

A. Synergists
B. Antagonists
C. Agonists
D. Fixators

Correct answer: B

Rationale: Antagonist muscles are pairs of muscles that work in opposition to each other, producing opposing movements. When one muscle contracts, the other relaxes to allow the movement to occur smoothly. Synergists are muscles that work together to create a movement, not in opposition. Agonists are muscles primarily responsible for producing a specific movement, not opposing each other. Fixators are muscles that stabilize joints to allow other movements to take place, providing a stable base for muscle actions but do not produce opposing movements.

3. Which of the following is an example of Mendelian inheritance?

A. Incomplete Dominance
B. Polygenic Alleles
C. Combination Inheritance
D. Recessive Inheritance

Correct answer: D

Rationale: The correct answer is D, 'Recessive Inheritance.' Mendelian inheritance involves traits controlled by single genes with dominant and recessive alleles. Incomplete dominance (choice A) is a non-Mendelian inheritance pattern where the heterozygous phenotype is a blend of the two homozygous phenotypes. Polygenic alleles (choice B) involve multiple genes contributing to a single trait, not following Mendelian principles. Combination inheritance (choice C) is not a recognized term in genetics and does not describe Mendelian inheritance patterns.

4. Which component of the nervous system is responsible for controlling voluntary movements, such as the contraction of skeletal muscles?

A. Autonomic nervous system
B. Peripheral nervous system
C. Somatic nervous system
D. Sympathetic nervous system

Correct answer: C

Rationale: The correct answer is C: Somatic nervous system. The somatic nervous system is responsible for controlling voluntary movements, such as the contraction of skeletal muscles. This system consists of motor neurons that send signals from the central nervous system to the skeletal muscles, allowing for conscious control over movement. The autonomic nervous system (A) controls involuntary functions like heart rate and digestion, the peripheral nervous system (B) includes all nerves outside the central nervous system, and the sympathetic nervous system (D) is a division of the autonomic nervous system responsible for the fight-or-flight response. Therefore, choices A, B, and D are incorrect as they do not specifically regulate voluntary movements of skeletal muscles, which is a function of the somatic nervous system.