Explanation:
Limitations of Correlations
Correlation is not and cannot be taken to imply causation. Even if there is a very strong association between two variables we cannot assume that one causes the other. For example suppose we found a positive correlation between watching violence on T.V. and violent behavior in adolescence.
An important limitation of correlational research designs is that they cannot be used to draw conclusions about the causal relationships among the measured variables. Consider, for instance, a researcher who has hypothesized that viewing violent behavior will cause increased aggressive play in children
Answer : A, B , C
Explanation: the second option
The groups of plants are pteridophytes (ferns), Bryophytes (mosses) and lichens.
Algae is not a good answer since they live in an aquatic environment.
Plants without flowers (ferns, mosses, lichens) have neither flowers nor seeds. They can colonize various environments, terrestrial or aquatic. Ferns and mosses for example settle between the stones of an old well. The reproduction of plants without flowers is mainly due to spores.
Answer:
The statement that is true about leukotrienes is that they create excess mucus in the airways (last option).
Explanation:
Leukotrienes are inflammatory mediators, derived from arachidonic acid, in whose presence occurs increased vascular permeability in tissues, leading to inflammatory processes.
The presence of leukotrienes has been related to the development of allergic reactions, mainly in the respiratory tract, producing edema in the mucosa, contraction of the smooth muscles of the airways and increased production of mucus
in the airways.
the other options are not correct because leukotrienes:
- <em>Produce contraction of the smooth musculature around the airway.
</em>
- <em>Are related to the production of bronchial asthma.
</em>
- <em>Are inflammatory (chemical) mediators. </em>