What is the length of DNA that can code for a particular protein?

Correct Answer: C

Rationale: The correct answer is C: Gene. A gene is a specific segment of DNA that contains the information necessary to produce a particular protein. Genes are responsible for coding proteins, and each gene carries the instructions for a specific protein. Chromosomes consist of many genes and are not a specific length that codes for a protein. Nucleotides are the building blocks of DNA and are not a length that codes for a protein. Ribosomes are cellular organelles involved in protein synthesis and do not directly code for proteins.

Correct Answer: D

Rationale: Density is determined by the formula Density = Mass / Volume. For this rock, the mass is 3g, and the volume is 4 cm³. Applying the formula: Density = 3g / 4cm³ = 0.75 g/cm³. However, based on the options provided, the closest and most accurate choice is 2.65 g/cm³, corresponding to option D. Choice A, 8.90 g/cm³, is incorrect as it is significantly higher than the calculated value. Choice B, 0.38 g/cm³, and Choice C, 77.22 g/cm³, are also incorrect and do not match the correct calculation.

Correct Answer: A

Rationale: The correct answer is A: Lag, exponential, stationary, death. The phases of bacterial growth start with the lag phase where bacteria acclimate to their environment, followed by the exponential phase characterized by rapid growth. This is then followed by the stationary phase where growth slows as resources deplete, and finally, the death phase where the population declines. Choice B is incorrect as it has the order of phases mixed up. Choice C is incorrect as it also has the order of phases mixed up. Choice D is incorrect as it has the stationary phase occurring before the exponential phase, which is inaccurate.

Correct Answer: C

Rationale: The correct order of structures found beneath the rib in descending order is Vein → Artery → Nerve. This sequence is important to remember for medical procedures like inserting a chest tube to ensure precision and avoid complications. Choice A is incorrect because the nerve is not typically the structure closest to the rib. Choice B is incorrect as the vein is usually closer to the rib than the nerve. Choice D is incorrect as the artery is usually closer to the rib than the nerve.

Correct Answer: A

Rationale: The correct answer is A: Negative feedback loop. Negative feedback loops work to inhibit the stimulus or reduce the deviation from a set point, maintaining homeostasis by counteracting any changes from the norm. In this case, the negative feedback loop acts to minimize any deviation from the body's internal balance, ensuring stability and optimal functioning. Choice B, a positive feedback loop, amplifies the stimulus or deviation, moving systems away from homeostasis. Choice C, an inhibitory feedback loop, is not a commonly recognized term in the context of feedback mechanisms. Choice D, a stimulating feedback loop, is not a standard term and does not accurately describe a feedback loop's role in maintaining homeostasis.

Correct Answer: A

Rationale: The primary processes involved in breathing are inspiration (inhaling air) and expiration (exhaling air). Inspiration is the process of taking air into the lungs, while expiration is the process of expelling air from the lungs. These two phases are crucial for gas exchange, where oxygen is taken in during inspiration and carbon dioxide is expelled during expiration. Choices B, C, and D are incorrect as they either combine inspiration with respiration or include unrelated processes like respiration and circulation. Therefore, the correct pair of processes involved in breathing is A, inspiration and expiration.

Correct Answer: B

Rationale: The correct answer is B: Skeletal, cardiac, smooth. Skeletal muscle tissue is responsible for voluntary movement, cardiac muscle tissue is found in the heart and is responsible for involuntary heart contractions, and smooth muscle tissue is located in organs and is responsible for involuntary movements. Therefore, the three types of muscle tissues are skeletal, cardiac, and smooth. Choices A, C, and D are incorrect because they include types of tissues that are not classified as muscle tissues. Epithelial and connective tissues are different types of tissues that serve other functions in the body, not related to muscle contractions.

Correct Answer: B

Rationale: The endocrine system does not include a transportation network throughout the body. While the cardiovascular system transports blood, oxygen, and nutrients, the immune system has lymphatic vessels for immune cell transportation, and the nervous system transmits signals via neurons. In contrast, the endocrine system coordinates bodily functions by releasing hormones directly into the bloodstream, which then act on target organs or tissues. This delivery mechanism is different from the continuous transportation networks found in the other systems listed, making the endocrine system the correct choice for this question.

Correct Answer: A

Rationale: In the standard anatomical position, plane 1 (coronal/frontal plane) divides the body into anterior and posterior portions, plane 2 (sagittal plane) divides the body into left and right portions, and plane 3 (transverse/horizontal plane) divides the body into superior and inferior portions. Therefore, the correct sequence is Plane 1 as coronal, Plane 2 as sagittal, and Plane 3 as transverse, which corresponds to Choice A. Choice B is incorrect as it misidentifies the planes. Plane 2 cannot be coronal as it specifically divides the body into left and right portions. Choice C is incorrect as it misidentifies Plane 2 as sagittal when it should be coronal. Choice D is incorrect as it incorrectly designates Plane 2 as coronal when it should be sagittal, leading to an inaccurate sequence of the primary body planes.