which of the following describes how atomic radius varies across the periodic table

ATI TEAS 7

TEAS 7 Science Practice Test

1. Which of the following describes how atomic radius varies across the periodic table?

A. Atomic radius increases from top to bottom and left to right on the periodic table.
B. Atomic radius increases from top to bottom and right to left on the periodic table.
C. Atomic radius increases from top to bottom and toward the halogens on the periodic table.
D. Atomic radius increases from top to bottom and toward the noble gases on the periodic table.

Correct answer: A

Rationale: Atomic radius tends to increase from top to bottom and left to right on the periodic table. This is because as you move down a group (top to bottom), new energy levels are added, increasing the distance of the outer electrons from the nucleus and thus increasing the size of the atom. On the other hand, as you move from left to right across a period, the number of protons and electrons increases, leading to a stronger nuclear charge that attracts the electrons closer to the nucleus, resulting in smaller atomic radii. Choice B is incorrect as atomic radius does not increase from right to left. Choices C and D are incorrect as they incorrectly associate the trend with specific groups of elements (halogens and noble gases) rather than the general trend observed on the periodic table.

2. The fossil record shows that dinosaurs with feathers existed millions of years before birds. This is evidence for

A. Convergent evolution (unrelated organisms evolving similar traits)
B. Divergent evolution (related organisms evolving different traits)
C. Coevolution (two species influencing each other's evolution)
D. The extinction of dinosaurs due to an asteroid impact

Correct answer: A

Rationale: The fossil record indicates that dinosaurs had feathers before birds, suggesting convergent evolution. Convergent evolution occurs when unrelated organisms independently evolve similar traits to adapt to similar environmental pressures. In this case, both dinosaurs and birds developed feathers for flight or insulation purposes, even though they are not closely related. This evidence supports the concept of convergent evolution rather than divergent evolution, coevolution, or the extinction of dinosaurs due to an asteroid impact. Therefore, the correct answer is A, as it best explains the scenario where dinosaurs with feathers existed before birds, showcasing the concept of unrelated organisms evolving similar traits independently.

3. Which plane divides the body into left and right halves?

A. Sagittal/Median Plane
B. Frontal/Coronal Plane
C. Transverse/Cross-Section Plane
D. Horizontal Plane

Correct answer: A

Rationale: The correct answer is A: Sagittal/Median Plane. This plane divides the body into left and right halves. The Frontal/Coronal Plane (choice B) divides the body into front and back, while the Transverse/Cross-Section Plane (choice C) divides it into top and bottom. The Horizontal Plane (choice D) divides the body into upper and lower portions. Understanding these planes is essential in anatomy as they help describe the orientation and relationships of body structures.

4. What is the term for a group of organisms with the same genetic makeup?

A. Population
B. Clone
C. Genotype
D. Species

Correct answer: B

Rationale: In this context, a clone (option B) is a group of organisms that are genetically identical because they are derived from a single ancestor. A population (option A) refers to a group of individuals of the same species living in the same area. Genotype (option C) refers to the genetic makeup of an individual organism. Species (option D) refers to a group of organisms that can interbreed and produce fertile offspring. Therefore, the most appropriate choice for the question is 'Clone,' as it specifically refers to organisms with the same genetic makeup.

5. What do nociceptors detect?

A. Deep pressure
B. Vibration
C. Pain
D. Temperature

Correct answer: C

Rationale: Nociceptors are specialized sensory receptors that detect and transmit signals related to pain. These receptors are activated by noxious stimuli that can potentially cause tissue damage or injury, triggering the perception of pain in the brain. Therefore, the correct answer is 'Pain.' Choices A, B, and D are incorrect because nociceptors specifically respond to painful stimuli, not deep pressure, vibration, or temperature.