a closed system in ecology is one that

ATI TEAS 7

TEAS Test 7 science quizlet

1. In ecology, what defines a closed system?

A. Exchanges energy but not matter
B. Exchanges both energy and matter
C. Exchanges neither energy nor matter
D. Recycles nutrients efficiently

Correct answer: A

Rationale: In ecology, a closed system is one that does not exchange matter with its surroundings but can exchange energy. This means that while energy can enter or leave the system, the amount of matter within the system remains constant. Option A correctly defines a closed system in ecology. Choices B and C are incorrect as a closed system does not exchange matter or energy. Option D is unrelated to the concept of a closed system in ecology.

2. Which muscle causes a joint to bend?

A. Cardiac
B. Extension
C. Flexor
D. Smooth

Correct answer: C

Rationale: The correct answer is C: Flexor. A flexor muscle contracts to bend a joint, such as bending the elbow or knee. Flexor muscles are responsible for flexing or bending a joint, while extensor muscles are responsible for extending or straightening a joint. Choice A, Cardiac, is incorrect as cardiac muscle is found in the heart and is responsible for pumping blood. Choice B, Extension, is incorrect as extension refers to the straightening or extending movement of a joint, which is opposite to bending. Choice D, Smooth, is incorrect as smooth muscles are involuntary muscles found in organs like the intestines and blood vessels, not directly responsible for bending joints.

3. Which of the following describes the difference between prokaryotic and eukaryotic cells?

A. Prokaryotic cells have a nucleus, while eukaryotic cells don't.
B. Eukaryotic cells are simpler in structure than prokaryotic cells.
C. Prokaryotic cells have membrane-bound organelles, while eukaryotic cells don't.
D. Eukaryotic cells have a true nucleus and membrane-bound organelles, while prokaryotic cells lack these.

Correct answer: D

Rationale: Eukaryotic cells have a true nucleus that contains the genetic material, while prokaryotic cells lack a true nucleus. Eukaryotic cells also have membrane-bound organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus, which are absent in prokaryotic cells.

4. What is the medical term for heartburn, a burning sensation in the chest caused by stomach acid?

A. Dysphagia
B. Gastroesophageal reflux disease (GERD)
C. Peptic ulcer
D. Ulcerative colitis

Correct answer: B

Rationale: A) Dysphagia refers to difficulty swallowing and is not specifically related to heartburn. B) Gastroesophageal reflux disease (GERD) is the medical term for heartburn, which is a burning sensation in the chest caused by stomach acid flowing back up into the esophagus. C) Peptic ulcer is a sore that develops on the lining of the stomach, small intestine, or esophagus, and it can cause symptoms such as abdominal pain, not specifically heartburn. D) Ulcerative colitis is a type of inflammatory bowel disease that affects the colon and rectum, and it does not typically cause heartburn.

5. What type of genetic variation is caused by changes in the DNA sequence?

A. Epigenetic variation
B. Phenotypic variation
C. Genotypic variation
D. Behavioral variation

Correct answer: C

Rationale: A) Epigenetic variation refers to changes in gene expression that do not involve alterations in the DNA sequence itself. These changes can be influenced by environmental factors. B) Phenotypic variation refers to differences in observable traits or characteristics of an organism, which can be influenced by both genetic and environmental factors. C) Genotypic variation is caused by changes in the DNA sequence, such as mutations or genetic recombination. These changes directly impact the genetic information carried by an organism. D) Behavioral variation refers to differences in behavior among individuals of the same species, which can be influenced by genetic, environmental, and experiential factors.