Nokea
is a gaseous by-product of natural gas combustion plant hormone
- A. auxin
- B. Gibberellins
- C. Ethylene
- D. All above
Correct Answer: C
Rationale: The correct answer is C: Ethylene. Ethylene is indeed a gaseous plant hormone produced during the combustion of natural gas. It plays a crucial role in various plant processes such as fruit ripening, senescence, and stress responses.
A: Auxin is not a gaseous hormone and is primarily involved in promoting cell elongation and root growth.
B: Gibberellins are not gaseous hormones and mainly regulate plant growth processes like stem elongation and seed germination.
D: The statement "All above" is incorrect as auxin and gibberellins are not gaseous hormones, only ethylene fits the description.
Therefore, choice C, Ethylene, is the correct answer as it is the gaseous by-product of natural gas combustion and a plant hormone.
You may also like to solve these questions
A patient prescribed corticosteroids for arthritis is surprised to learn of an immune disorder. What should the nurse explain as the reason for the patient not demonstrating typical signs of immune dysfunction?
- A. The arthritis is masking the normal immune response.
- B. The corticosteroids are causing the thymus gland to malfunction.
- C. The arthritis is interfering with the function of immunoglobulins.
- D. Corticosteroids are impacting normal immune response functioning.
Correct Answer: D
Rationale: The correct answer is D because corticosteroids are known to suppress the immune system by inhibiting the production of pro-inflammatory cytokines and preventing the activation of immune cells. This suppression can lead to a decreased immune response, making it less likely for the patient to exhibit typical signs of immune dysfunction.
A: The arthritis masking the immune response is not a plausible explanation as arthritis does not directly affect immune function.
B: Corticosteroids do not cause the thymus gland to malfunction; they mainly impact immune response at the cellular level.
C: Arthritis affecting immunoglobulin function is not a common mechanism of immune dysfunction in this context.
The basic structure of an antibody molecule is
- A. One light chain and one heavy chain that are covalently linked and form one antigen binding site
- B. Two identical heavy chains and two identical light chains that are covalently linked and form two antigen binding sites
- C. Two identical heavy chains and two identical light chains covalently linked to form one antigen binding site
- D. Two identical light chains that form the antigen binding site and two identical heavy chains that mediate the effector functions of antibodies
Correct Answer: B
Rationale: Rationale for Answer B:
1. Antibody structure consists of two identical heavy chains and two identical light chains.
2. These chains are covalently linked to form the Y-shaped structure of an antibody.
3. Each chain contributes to the formation of antigen-binding sites.
4. Therefore, two identical heavy chains and two identical light chains form two antigen-binding sites.
Summary of Incorrect Choices:
A: Incorrect because it describes only one antigen-binding site formed by one light chain and one heavy chain.
C: Incorrect because it describes one antigen-binding site formed by two identical heavy chains and two identical light chains.
D: Incorrect because it incorrectly describes the roles of light and heavy chains in antibody structure.
Identify the correct statement(s). In eukaryotic microorganisms:
- A. mRNA is short-lived (minutes).
- B. a single, circular chromosome is present.
- C. 5s, 16s, and 23s ribosomal RNA's are present.
- D. extrachromosomal DNA can be present.
Correct Answer: D
Rationale: The correct answer is D because extrachromosomal DNA, such as plasmids, can be present in eukaryotic microorganisms. This is true for certain organisms like yeast and some fungi. These DNA molecules are separate from the main chromosomal DNA and can carry additional genetic information.
A: mRNA in eukaryotic microorganisms is not short-lived; it can have varying lifespans depending on the specific mRNA molecule and cellular conditions.
B: Eukaryotic microorganisms typically have multiple linear chromosomes, not a single circular chromosome.
C: While 5s, 16s, and 23s ribosomal RNAs are present in prokaryotic organisms, eukaryotic microorganisms have different types of ribosomal RNA subunits.
Which pathway of the complement system involves properdin, Factor B, and Factor D?
- A. Classical pathway
- B. Alternative pathway
- C. Lectin pathway
- D. Terminal pathway
Correct Answer: B
Rationale: The correct answer is B: Alternative pathway. This pathway involves properdin, Factor B, and Factor D. Properdin stabilizes the C3 convertase complex formed by Factor B and Factor D, leading to the amplification of the complement cascade. The other choices are incorrect because:
A: Classical pathway is initiated by antigen-antibody complexes binding to C1q.
C: Lectin pathway is activated by lectins binding to carbohydrates on pathogen surfaces.
D: Terminal pathway involves the formation of the membrane attack complex.
If HLA-DR4 is considered a 'risk' allele for disease 'X', this means:
- A. All individuals with the HLA-DR4 allele will get disease X
- B. All individuals with disease X have the HLA-DR4 allele
- C. An individual with the HLA-DR4 allele has an increased chance of developing disease X compared to other individuals
- D. All of the above are true
Correct Answer: C
Rationale: The correct answer is C because having the HLA-DR4 allele increases the likelihood of developing disease X but does not guarantee it. Choice A is incorrect because not all individuals with HLA-DR4 will get disease X. Choice B is incorrect because not all individuals with disease X have the HLA-DR4 allele. Choice D is incorrect because it falsely states that all statements are true, which is not the case.