Nokea
Which of the following cells transfers pigment granules to adjust epidermal cells?
- A. Merkel Cells
- B. Keratinocytes
- C. Langerhans cells
- D. Melanocytes
Correct Answer: D
Rationale: Melanocytes are the cells responsible for transferring pigment granules to adjust epidermal cells. Melanocytes produce melanin, the pigment that gives skin its color and provides protection against UV radiation. Once produced, melanin is transferred to neighboring skin cells, primarily keratinocytes, to distribute the pigment throughout the epidermis. Merkel cells are associated with the sense of touch, not pigment transfer. Keratinocytes are the predominant cells in the epidermis that produce keratin, a structural protein for skin, nails, and hair. Langerhans cells are part of the immune system in the skin, helping to recognize and respond to foreign invaders.
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What is the function of sodium bicarbonate released by the pancreas?
- A. Sodium bicarbonate neutralizes the acidity of chyme.
- B. Sodium bicarbonate stimulates the protease that digests carbonates.
- C. Sodium bicarbonate inhibits peristalsis.
- D. Sodium bicarbonate stimulates the protease.
Correct Answer: A
Rationale: The correct answer is A because sodium bicarbonate released by the pancreas functions by neutralizing the acidity of chyme in the small intestine. This action helps to create a more alkaline environment, which is crucial for the activity of pancreatic enzymes and the absorption of nutrients. Option B is incorrect as sodium bicarbonate itself does not stimulate a protease to digest carbonates. Option C is incorrect as sodium bicarbonate does not inhibit peristalsis; instead, it aids in digestion. Option D is incorrect as sodium bicarbonate does not directly stimulate the protease but rather helps in maintaining the optimal pH for enzyme activity.
What is the term given to the sequence of nucleotides that contains the information to make a specific protein molecule?
- A. Gene
- B. Locus
- C. Promoter
- D. Operator
Correct Answer: A
Rationale: The correct answer is A: Gene. A gene is the term used to describe the sequence of nucleotides that contains the information necessary to synthesize a specific protein molecule. Genes act as the fundamental units of heredity and provide the instructions for building proteins, which play crucial roles in various biological processes within an organism. In contrast, a locus refers to the specific position or location of a gene on a chromosome. Promoter is a regulatory region of DNA that initiates the transcription process for a particular gene, while an operator is a DNA segment that interacts with a repressor protein to modulate the expression of neighboring genes.
Which of the following proteins is present in blood plasma?
- A. Fibrinogen
- B. Lymphocytes
- C. Monocytes
- D. Platelets
Correct Answer: A
Rationale: The correct answer is A: Fibrinogen. Fibrinogen is a vital protein present in blood plasma that plays a key role in blood clotting. Lymphocytes, monocytes, and platelets are different types of blood cells and not proteins found in blood plasma. Understanding the components of blood plasma, such as fibrinogen, is essential for comprehending its functions in various physiological processes, particularly in clot formation.
Which of the following pathways best represents the flow of blood from the human heart to organs?
- A. Blood pumped from the heart first enters arteries that then narrow to form arterioles that deliver blood to capillaries of the organs
- B. Blood pumped from the heart first enters veins that then narrow to form venules that deliver blood to arteries of the organ
- C. Blood pumped from the heart first enters arteries that then narrow to form arterioles that deliver blood to capillaries of the organs
- D. Blood pumped from the heart first enters arteries that then narrow to form veins that deliver blood to the organs
Correct Answer: C
Rationale: The correct pathway for the flow of blood from the human heart to organs involves a series of blood vessels. Blood is pumped from the heart into large arteries, which then branch into smaller arterioles. These arterioles deliver blood to capillaries located in the organs. Capillaries are essential for the exchange of nutrients, gases, and waste products between the blood and the tissues. This intricate network ensures efficient delivery of oxygen and nutrients to the organs and removal of waste products. Therefore, the correct sequence is for blood to flow from the heart, through arteries, then arterioles, and finally to capillaries in the organs for optimal exchange and organ function.
To accurately measure the density of a series of small irregular solids made of plastic, wood, fiberglass, and glass, which of the following laboratory tools will a student need?
- A. Graduated cylinder, water, weighing balance
- B. Weighing balance, Bunsen burner, metric ruler
- C. Graduated cylinder, spectrophotometer, water
- D. Graduated beaker, metric ruler, water
Correct Answer: A
Rationale: To accurately measure the density of irregular solids made of various materials, a student needs specific laboratory tools. Firstly, a graduated cylinder is required to measure the volume of the irregular solids using the water displacement method, which allows for precise volume determination. Secondly, a weighing balance is necessary to measure the mass of the irregular solids accurately. Density is calculated by dividing the mass by the volume, hence the need for both mass and volume measurements. Therefore, the essential tools for this task are a combination of a graduated cylinder, water, and weighing balance (Choice A). These tools together provide the necessary measurements for calculating the density of the irregular solids accurately.