Ans.
Cell-to-cell communication allows signalling of essential substances between the plant cells, which are surrounded by cell walls. The molecules used by plants for long-distance signalling are known as hormones, such as auxin, ethylene, and gibberelin.
These hormones are secreted by one plant cell and received by another plant cell, where it exerts it affect. Thus, the correct answer to be fill in the blank is 'option A). hormones.'
Answer:
Killer whales are found in all oceans. While they are most abundant in colder waters like Antarctica, Norway, and Alaska, they are also found in tropical and subtropical waters. The most well-studied killer whale populations occur in the eastern North Pacific Ocean.
Explanation:
The answer is commensalism.
<span>Commensalism is a relationship between two organisms in which only one of them has benefit, and the other one is not affected (it has no harm or benefit).
</span>In this example, clownfish has the benefit - it is protected from predators by sea anemones. <span>The sea anemone isn't harmed and doesn't benefit from this relationship. Hence, this is the example of commensalism.</span>
<span>The exfoliative toxin is responsible for a skin disease called staphylococcal scalded skin syndrome. This exotoxin, exfoliatin is produced by Staphylococcus aureus and it induces the formation of fluid-filled blisters with easily ruptured, thin walls, usually in infants. Exfoliatin has the protease activity which causes peeling of the skin by destroying adhesion between keratinocytes (skin cells).</span>
The species is on CITES Appendix II, but its status is poorly known. The IUCN Red-List (2007, www.iucnredlist.org) classified it as Lower Risk/Least Concern
