Nokea
Which type of cell has a nucleus but lacks membrane-bound organelles?
- A. Plant cell
- B. Prokaryotic cell
- C. Animal cell
- D. Fungal cell
Correct Answer: B
Rationale: The correct answer is B: Prokaryotic cell. Prokaryotic cells are characterized by having a nucleus that is not enclosed within a membrane (nuclear envelope) and lacking membrane-bound organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus. Plant, animal, and fungal cells are eukaryotic cells, which have a true nucleus enclosed within a nuclear envelope and contain membrane-bound organelles. Therefore, options A, C, and D are incorrect as they all represent eukaryotic cells that possess membrane-bound organelles.
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What is the term for a group of organisms that can interbreed and produce fertile offspring?
- A. Genus
- B. Phylum
- C. Kingdom
- D. Species
Correct Answer: D
Rationale: A species is defined as a group of organisms that can interbreed and produce fertile offspring, which is a fundamental concept in biology. This ability to interbreed and produce fertile offspring is a key characteristic that distinguishes one species from another. Genus (option A) refers to a taxonomic rank that includes one or more closely related species, not the ability to interbreed. Phylum (option B) and kingdom (option C) are higher taxonomic ranks that encompass a broader range of organisms, not specifically defined by interbreeding and fertile offspring production. Therefore, the correct answer is 'Species.'
Elements tend to gain or lose electrons to achieve stable electron configurations like those of noble gases. Their group number often indicates the number of electrons gained/lost and the resulting ionic charge, providing a good starting point for prediction.
- A. Ionic bonds involve electron sharing, while metallic bonds involve electron transfer.
- B. Ionic bonds are weak and directional, while metallic bonds are strong and non-directional.
- C. Ionic bonds exist between metals and non-metals, while metallic bonds exist only between metals.
- D. Ionic bonds form discrete molecules, while metallic bonds form extended structures.
Correct Answer: C
Rationale: Ionic bonds typically form between metals and non-metals, where one atom donates electrons (cation) and the other accepts electrons (anion). This results in the transfer of electrons. Metallic bonds, on the other hand, occur between metal atoms where electrons are shared among a sea of delocalized electrons, leading to the characteristic properties of metals like malleability and conductivity. Choice A is incorrect because ionic bonds involve electron transfer, not sharing. Choice B is incorrect as ionic bonds are strong, not weak, and are non-directional, while metallic bonds are strong and non-directional. Choice D is incorrect as ionic bonds do not form discrete molecules but rather a lattice structure, whereas metallic bonds form extended structures.
What properties distinguish laser light from typical light sources?
- A. Enhanced brightness only
- B. Monochromatic nature (single color) and coherence (synchronized waves)
- C. Increased velocity
- D. Limited visibility to the human eye
Correct Answer: B
Rationale: Laser light differs from typical light sources due to its monochromatic nature (single color) and coherence (synchronized waves). This means that laser light consists of a single wavelength and synchronized waves, unlike typical light sources that emit a range of wavelengths and are incoherent. The monochromatic nature of laser light allows it to be of a single color, while coherence ensures that the waves are synchronized. These unique properties of laser light make it valuable for a wide range of applications in fields such as medicine, industry, and research. Choices A, C, and D are incorrect because laser light's distinguishing features are not related to enhanced brightness, increased velocity, or limited visibility to the human eye. Instead, it is the monochromatic nature and coherence that set laser light apart from typical light sources.
What is the medical term for an ingrown hair?
- A. Folliculitis
- B. Hirsutism
- C. Pseudofolliculitis Barbae
- D. Alopecia
Correct Answer: A
Rationale: The correct answer is A, Folliculitis. Folliculitis is the medical term for the inflammation of hair follicles, which can be caused by ingrown hairs. Hirsutism refers to excessive hair growth, pseudofolliculitis barbae is a condition where shaving causes ingrown hairs, and alopecia is hair loss. Therefore, choices B, C, and D are incorrect as they do not specifically refer to ingrown hairs.
What is the term for the process of a liquid changing into a gas?
- A. Evaporation
- B. Boiling
- C. Condensation
- D. Sublimation
Correct Answer: A
Rationale: The correct answer is 'Evaporation.' Evaporation is the process by which a liquid changes into a gas at any temperature, while boiling specifically refers to the rapid vaporization of a liquid only at its boiling point. Condensation is the opposite process of gas turning into a liquid, and sublimation is the direct transition from solid to gas without passing through the liquid phase.