ATI TEAS 7
Mometrix TEAS 7 science practice test
1. Which of the following is the smallest part of an element that can still be recognized as that element?
- A. Electron
- B. Proton
- C. Neutron
- D. Atom
Correct answer: D
Rationale: An atom is the smallest unit of matter that retains the chemical properties of an element. It consists of a nucleus containing protons and neutrons, surrounded by electrons that orbit the nucleus. The number of protons in the nucleus defines the atomic number of the element, and the number of neutrons determines the isotope of the element. While electrons, protons, and neutrons are fundamental particles, an atom as a whole is the smallest part of an element that maintains its unique identity. Electrons are negatively charged particles orbiting the nucleus, protons are positively charged particles in the nucleus, and neutrons are neutral particles in the nucleus. Therefore, the correct answer is 'D: Atom.'
2. Which hormone is responsible for regulating the body's metabolism?
- A. Insulin
- B. Thyroxine
- C. Melatonin
- D. Adrenaline
Correct answer: B
Rationale: Thyroxine, also known as T4, is produced by the thyroid gland and plays a vital role in regulating the body's metabolism. Insulin is not responsible for regulating metabolism; instead, it helps regulate blood sugar levels. Melatonin is involved in regulating sleep-wake cycles, not metabolism. Adrenaline, also known as epinephrine, is a stress hormone that prepares the body for fight or flight responses, not primarily involved in metabolic regulation.
3. What are energy levels and orbitals?
- A. Energy levels are the paths that electrons travel around the nucleus of an atom, and orbitals are the regions where electrons are most likely to be found.
- B. Energy levels are the regions where electrons are most likely to be found, and orbitals are the paths that electrons travel around the nucleus of an atom.
- C. Energy levels are the same as orbitals.
- D. Energy levels and orbitals do not exist.
Correct answer: A
Rationale: Energy levels refer to the specific energies that electrons in an atom can have, while orbitals are the regions within an atom where electrons are most likely to be found. Electrons do not travel in fixed paths around the nucleus like planets around the sun, as suggested in option B. Option C is incorrect because energy levels and orbitals are distinct concepts in atomic structure. Option D is incorrect as energy levels and orbitals are fundamental concepts in understanding the behavior of electrons in atoms.
4. The innate immune system provides a non-specific first line of defense. What are some physical barriers that contribute to the innate immune system?
- A. Antibodies
- B. Phagocytes
- C. Skin and mucous membranes
- D. Memory B cells
Correct answer: C
Rationale: Physical barriers such as the skin and mucous membranes are crucial components of the innate immune system's first line of defense. These barriers act as physical obstacles that prevent pathogens from entering the body. Antibodies (option A) are produced by the adaptive immune system in response to specific pathogens and do not serve as physical barriers. Phagocytes (option B) are cells that engulf and digest pathogens, playing a role in the innate immune response but not as physical barriers. Memory B cells (option D) are part of the adaptive immune system and aid in mounting a faster and more effective immune response upon subsequent exposure to a specific pathogen, but they are not physical barriers against initial pathogen entry.
5. What is the basic unit of heredity?
- A. Chromosome
- B. Cell
- C. Gene
- D. Organ
Correct answer: C
Rationale: A gene is the basic unit of heredity that carries the instructions for making proteins, which determine an organism's traits. Genes are segments of DNA located on chromosomes within the cell. While chromosomes contain many genes, a gene itself is the fundamental unit of heredity responsible for passing on genetic information from one generation to the next. Cells are the basic structural and functional units of living organisms, but genes specifically carry genetic information. Organs are composed of tissues and serve specific functions within an organism, but they are not the basic unit of heredity.
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