Which of the following describes a typical gas?

Correct Answer: B

Rationale: The correct answer is B: 'Indefinite shape and definite volume.' A gas does not have a definite shape as it takes the shape of its container, conforming to its surroundings. However, a gas does have a definite volume because it fills the entire volume of the container it occupies. This characteristic allows gases to expand to fill the available space provided by the container, while their volume remains constant within that container. Choice A is incorrect because gases do not have an indefinite volume but rather a definite volume. Choice C is incorrect as gases do not have a definite shape but take the shape of their container. Choice D is incorrect as gases do not have a definite shape and their volume is definite, not indefinite.

Correct Answer: D

Rationale: The correct answer is D: Epithelial. The epidermis is composed of epithelial cells, specifically called keratinocytes, which are responsible for producing keratin, a protein that provides the skin with strength and flexibility. Epithelial cells form the protective outer layer of the skin and play a crucial role in skin repair and regeneration. Choice A - Osteoclasts are cells involved in bone remodeling, not found in the epidermis. Choice B - Connective tissue cells are not the primary cells found in the epidermis. They are more commonly found in the dermis, providing structural support and elasticity to the skin. Choice C - Dendritic cells are part of the immune system and are present in the skin to help recognize pathogens and activate the immune response. However, they are not the main cell type that composes the epidermis.

Correct Answer: A

Rationale: The genotype provides information about the specific genetic makeup of an organism, including the alleles it possesses for a particular trait. This information is not always directly reflected in the phenotype, which is the observable physical characteristics of an organism. The genotype determines the proteins coded for by its alleles, but the phenotype is the expression of those proteins in the organism's traits. Therefore, the genotype necessarily includes the proteins coded for by its alleles, a detail not provided solely by the phenotype.\nChoice B is incorrect because the genotype may include dominant alleles as well, not just recessive ones. Choice C is incorrect because the genotype refers to genetic information, not physical characteristics. Choice D is incorrect because the genotype does not directly indicate what an organism's parents looked like; it primarily describes the genetic information inherited from parents.

Correct Answer: C

Rationale: The chief difference between evaporation and boiling is that evaporation can happen below a liquid's boiling point, while boiling only occurs at the liquid's boiling point. Evaporation is the process of a liquid turning into a gas at any temperature, while boiling specifically refers to the rapid vaporization that occurs when a liquid reaches its boiling point. Choice A is incorrect because liquids evaporate throughout the liquid, not just at the surface. Choice B is incorrect as evaporating substances change from liquid to gas, while boiling substances change from liquid to gas. Choice C is incorrect as boiling is not a man-made phenomenon; in fact, it is a natural process based on temperature changes. Choice D is incorrect because evaporation can happen naturally and is not limited to man-made processes.

Correct Answer: C

Rationale: Water is highly cohesive, meaning it is attracted to itself due to its hydrogen bonding properties. This cohesion is the reason why water has a high melting point compared to other liquids of similar molecular weight. It is crucial for the existence of life on Earth as it allows water to remain a liquid within a wide range of temperatures, providing a stable environment for biological processes to occur. Choices A, B, and D are incorrect. Water's cohesive property does not directly relate to its ability to flow through phospholipid bilayers, assist fish in breathing, or self-hydrolyze into hydrogen and oxygen.