Which of the following layers of skin lack blood vessels?
A. Papillary
B. Epidermis
C. Reticular
D. Hypodermis
The layer of skin that lacks blood vessels is the epidermis. The epidermis is the thin outer layer of the skin and does not have any blood vessels within it. It is composed of keratinized, stratified squamous epithelium and is made of four or five layers of epithelial cells, depending on its location in the body.
The other options are not correct because they do contain blood vessels. The papillary layer is part of the dermis, which contains blood vessels. The reticular layer is also part of the dermis and contains blood vessels . The hypodermis is a layer below the dermis and also contains blood vessels.
Therefore, the Correct Answer is B.
More Questions on TEAS 7 Science
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Q #1: Which of the following is the process in which an ovarian follicle matures and releases a reproductive egg?
A. Oogenesis
B. Menstruation
C. Ovulation
D. Fertilization
Answer Explanation
Ovulation is the process in which an ovarian follicle matures and releases a reproductive egg. During ovulation, the egg is released from the ovary and travels down the fallopian tube where it may be fertilized by sperm.
The other options are not processes in which an ovarian follicle matures and releases a reproductive egg. Oogenesis is the process of egg cell formation, menstruation is the shedding of the uterine lining, and fertilization is the fusion of an egg and sperm to form a zygote.
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Q #2: Use the table below to answer the question. Object Mass (g) Time of fall (sec) 1 5.0 2.0 2 5.0 1.0 3 30.0 0.5 4 35.0 1.5 Which of the following conclusions is supported by the data?
A. Objects A and B will fall at the same rate.
B. The greater the mass of an object, the faster it will fall.
C. The time of fall is independent of the mass of the object.
D. Air resistance could be greater for A than for B.
Answer Explanation
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Q #3: Which of the following actions allows for repolarization of a neuron?
A. The inhibition of sodium and potassium pumps, stopping all ion movement into the neuron
B. The opening of sodium channels, allowing sodium to enter the neuron
C. The closing of both sodium and potassium channels to restrict movement of ions into and out of the neuron
D. The opening of potassium channels allowing potassium to leave the neuron
Answer Explanation
D. The opening of potassium channels allowing potassium to leave the neuron
The correct answer is d. The opening of potassium channels allowing potassium to leave the neuron. Repolarization of a neuron occurs after an action potential, when the neuron's membrane potential returns to its resting state. This is achieved by the opening of potassium channels, which allows potassium ions to flow out of the neuron. This movement of positively charged ions out of the neuron helps to restore the negative membrane potential.
A. The inhibition of sodium and potassium pumps would not allow for repolarization because these pumps are necessary for maintaining the resting membrane potential.
B. The opening of sodium channels would cause depolarization, not repolarization.
C. The closing of both sodium and potassium channels would restrict ion movement, but it would not allow for repolarization.
