Answer:
Viral proteins can modify the most superficial portion in such a way that it is complementary to the receptor of the human cell.
Generally this happens due to a genetic recombination between an avian virus and a human virus within the respiratory epithelium of the pig: this process underlies the emergence of new, more virulent strains of the influenza virus and underlies the emergence of influenza pandemics
Answer:
Option C, open chemically gated sodium ion channels.
Explanation:
The nicotinic receptors are present on the muscle cell membrane. These receptors belong to the class of cholinergic receptor which binds to the acetylcholine and opens the gated channel to allow transfusion of cation through it. These actions of the receptors are stimulated by the neurotransmitter. Nicotinic receptors are very fast at acting and hence are more prevalent at the neuromuscular junction.
Hence, option C is correct
The cell wall is made up of tough stringy cellulose fibers.
Hope this helps!!
AnswerA recent forest fire has swept through the forest, killing many of the smaller organisms such as the hare, deer, and rodent populations that are prey for the larger organisms such as bobcats, wolves, and mountain lions. How would this affect the populations in the forest ecosystem?
Explanation:
Studying fossils allowed researchers to learn about organisms that lived long ago. The fossils provide as evolutionary evidence that shows how organisms in our present time have evolved over time and which common ancestors they are tied to. Fossils also provide information about climate change depending on the region and location they are found in. Fossils also date back to millenias ago, so fossils dated very far back in the past can help researchers infer that life had existed even farther than what they might have discovered. And finally, by studying fossils, you can determine how the organism may have died.
