Nokea
Which of the following mechanisms is responsible for the generation of diversity in the antigen-binding sites of immunoglobulins?
- A. Somatic hypermutation
- B. Gene rearrangement
- C. Isotype switching
- D. Clonal expansion
Correct Answer: A
Rationale: Somatic hypermutation is the mechanism responsible for generating diversity in the antigen-binding sites of immunoglobulins. During somatic hypermutation, point mutations are introduced into the variable regions of immunoglobulin genes in B cells. These mutations occur randomly and lead to a wide range of amino acid changes in the antigen-binding sites of antibodies. As a result, a diverse repertoire of antibodies with varying specificities for different antigens is created. Gene rearrangement and isotype switching are other mechanisms that contribute to antibody diversity but do not specifically target the antigen-binding sites. Clonal expansion, on the other hand, refers to the proliferation of specific B cell clones after activation by antigens, which amplifies the immune response but does not directly impact the diversity of antigen-binding sites.
You may also like to solve these questions
A patient presents with fever, chills, headache, and myalgia after returning from a camping trip. Laboratory tests reveal thrombocytopenia and leukopenia. Which of the following is the most likely causative agent?
- A. Plasmodium falciparum
- B. Trypanosoma cruzi
- C. Borrelia burgdorferi
- D. Leishmania donovani
Correct Answer: A
Rationale: The most likely causative agent in this scenario is Plasmodium falciparum, which is the parasite that causes malaria. The symptoms of fever, chills, headache, and myalgia following a camping trip are highly suggestive of malaria, especially if the patient has thrombocytopenia and leukopenia. Plasmodium falciparum is known to cause severe malaria with complications such as thrombocytopenia and leukopenia. The other options, Trypanosoma cruzi, Borrelia burgdorferi, and Leishmania donovani, do not typically present with all of the symptoms described and are not associated with the laboratory findings of thrombocytopenia and leukopenia.
Which of the following diagnostic tests is most appropriate for evaluating a woman with suspected cervical dysplasia?
- A. Pap smear
- B. Endometrial biopsy
- C. Colposcopy with biopsy
- D. Transvaginal ultrasound
Correct Answer: C
Rationale: Colposcopy with biopsy is the most appropriate diagnostic test for evaluating a woman with suspected cervical dysplasia. Colposcopy is a procedure in which a special magnifying instrument called a colposcope is used to examine the cervix for any abnormal areas. If abnormal tissue is identified during colposcopy, a biopsy will be taken to confirm the presence of cervical dysplasia and determine the severity. This allows for a more accurate diagnosis and appropriate management of the condition. Pap smear, although a screening test for cervical dysplasia, may not provide a definitive diagnosis and may require further evaluation with colposcopy and biopsy. Endometrial biopsy and transvaginal ultrasound are not indicated for evaluating cervical dysplasia specifically.
Nurse Nora monitors the patient, knowing that which finding indicates an adequate contraction pattern?
- A. Three to 5 contractions in a 10-minute period, with resultant cervical dilatation
- B. Four contractions every 5 minutes, without resultant cervical dilatation
- C. one contraction every 10 minutes, without resultant cervical
- D. One contraction per minute, with resultant cervical dilatation
Correct Answer: A
Rationale: An adequate contraction pattern during labor is characterized by regular contractions occurring at a frequency of three to 5 contractions in a 10-minute period, with resultant cervical dilatation. This pattern indicates efficient uterine activity that is helping to progress labor by dilating the cervix. In option A, the contractions are occurring at an appropriate frequency and are resulting in cervical dilatation, making it the correct choice for indicating an adequate contraction pattern.
A patient presents with fever, chills, headache, and myalgia after returning from a trip to sub-Saharan Africa. Laboratory tests reveal intraerythrocytic ring forms and trophozoites on blood smear examination. Which of the following is the most likely causative agent?
- A. Plasmodium falciparum
- B. Trypanosoma cruzi
- C. Borrelia burgdorferi
- D. Leishmania donovani
Correct Answer: A
Rationale: The patient's symptoms of fever, chills, headache, and myalgia after returning from sub-Saharan Africa are consistent with malaria. Intraerythrocytic ring forms and trophozoites observed on blood smear examination are characteristic of Plasmodium species, particularly Plasmodium falciparum, which is the most common and deadliest species causing malaria in sub-Saharan Africa. Plasmodium falciparum can lead to severe complications, such as cerebral malaria, if not promptly treated. Trypanosoma cruzi causes Chagas disease, not malaria. Borrelia burgdorferi is responsible for Lyme disease, which typically presents with a different set of symptoms like erythema migrans rash. Leishmania donovani causes visceral leishmaniasis, not malaria.
The mother of the family asked Nurse Emma how to apply the anti -scabies lotion. The nurse should teach the family to apply anti -scabies lotion to _________.
- A. all skin areas
- B. open lesions
- C. affected skin
- D. Reddened areas
Correct Answer: A
Rationale: The correct way to apply anti-scabies lotion is to cover all skin areas, not just the affected areas or red areas. Scabies is a contagious skin condition caused by mites burrowing into the skin, so applying the lotion to all skin areas helps to eliminate the mites and prevent reinfestation. It is important to follow the instructions provided by the healthcare professional for proper application and treatment of scabies.