in the human skeleton which of the following lists some of the vertebrae in descending order

ATI TEAS 7

ATI TEAS Science Test

1. In the human skeleton, which of the following lists some of the vertebrae in descending order?

A. Atlas, axis, thoracic, lumbar, sacral, coccyx.
B. Axis, sacral, coccyx, atlas, lumbar, thoracic.
C. Thoracic, sacral, lumbar, axis, coccyx, atlas.
D. Coccyx, lumbar, axis, sacral, thoracic, atlas.

Correct answer: A

Rationale: The correct order of some of the vertebrae in the human skeleton in descending order is Atlas, Axis, Thoracic, Lumbar, Sacral, Coccyx. This sequence follows the typical arrangement from the top of the spine down towards the pelvis. Choice B is incorrect as it does not follow the descending order of vertebrae. Choice C is incorrect as it starts with Thoracic which is not the first vertebra in the descending order. Choice D is incorrect as it starts with Coccyx which is the last vertebra in the descending order.

2. Molecular clocks utilize the accumulation of mutations in DNA sequences to estimate the evolutionary divergence time between species. This method relies on the assumption that:

A. The rate of mutation is constant across all genes and all species.
B. Species with more morphological similarities diverged more recently.
C. Mutations are always beneficial and contribute to increased fitness.
D. The fossil record provides the most accurate estimates of evolutionary relationships.

Correct answer: A

Rationale: A molecular clock is a method used to estimate the time of divergence between species by measuring the accumulation of mutations in DNA sequences. This method relies on the assumption that mutations occur at a relatively constant rate over time. If the rate of mutation were not constant, it would be challenging to accurately estimate the evolutionary divergence time between species. Therefore, option A is the most appropriate choice as it aligns with the fundamental principle underlying the molecular clock hypothesis. Option B is incorrect because the assumption that species with more morphological similarities diverged more recently does not directly relate to the concept of molecular clocks and the accumulation of mutations in DNA sequences. Option C is incorrect because mutations are not always beneficial and do not always contribute to increased fitness. Mutations can be neutral or deleterious as well, and their accumulation is what is used to estimate evolutionary di

3. Which type of blood vessel carries oxygenated blood away from the heart?

A. Vein
B. Artery
C. Capillary
D. Lymphatic vessel

Correct answer: B

Rationale: The correct answer is B. Arteries carry oxygenated blood away from the heart to the rest of the body, delivering nutrients and oxygen to the tissues. Veins, on the other hand, carry deoxygenated blood back to the heart. Capillaries are where the exchange of gases, nutrients, and waste products occurs between the blood and tissues. Lymphatic vessels are responsible for transporting lymph, which is a clear fluid containing white blood cells and waste products, and play a key role in the immune system.

4. What is the primary function of the cell membrane?

A. To provide structural support for the cell
B. To transport substances in and out of the cell
C. To synthesize proteins and lipids
D. To store genetic material

Correct answer: B

Rationale: The primary function of the cell membrane, also known as the plasma membrane, is to regulate the movement of substances in and out of the cell. It acts as a selectively permeable barrier, allowing specific molecules to pass through while blocking others. This role is crucial for maintaining the internal environment of the cell by enabling essential nutrients to enter and waste products to exit. While the cell membrane provides some structural support for the cell, its main function is substance transport. Protein and lipid synthesis predominantly occur in organelles like the endoplasmic reticulum and Golgi apparatus, and storing genetic material is the nucleus's responsibility. Therefore, choices C (To synthesize proteins and lipids) and D (To store genetic material) are incorrect as these functions are carried out by other cell organelles, not the cell membrane.

5. What is the energy required to break a chemical bond called?

A. Kinetic energy
B. Potential energy
C. Activation energy
D. Bond energy

Correct answer: C

Rationale: Activation energy is the energy required to break a chemical bond and initiate a chemical reaction. It is the minimum amount of energy needed to start a chemical reaction by breaking bonds in the reactant molecules. Kinetic energy (option A) is the energy of motion and is not directly related to breaking chemical bonds. Potential energy (option B) is stored energy that can be converted into other forms of energy but is not specifically about breaking chemical bonds. Bond energy (option D) refers to the energy required to break a particular chemical bond in a molecule and is not the general term for the energy needed to break any chemical bond. Activation energy is crucial in determining the rate of a chemical reaction as it affects the probability of reactant molecules colliding with sufficient energy to surpass the energy barrier and form products.