Answer:
The correct answer is B.
Explanation:
Option A is wrong. Mammals were not the prominent species before the extinction of dinosaurs because the mammal species that lived during the dinosaurs' era were so small that they only weighed several grams and occupied small areas as their habitats.
Option C is wrong. As dinosaurs became extinct, reptiles and "birds" remained as their descendant which evolved to some of the species that we know today.
Option D is wrong. Pangea started to break up to form the geographic isolation for the diversion of many species around 175 million years ago.
So the correct answer is B. Massive extinction disrupts and changes the food chain in such a big way that it triggers a domino effect that leads to species adapting to their new environment and diversifying thus forming new species in the process.
I hope this answer helps.
Answer:
True
Explanation:
Bacteria generate toxins which can be classified as either exotoxins or endotoxins. Exotoxins are generated and actively secreted; endotoxins remain part of the bacteria. Usually, an endotoxin is part of the bacterial outer membrane, and it is not released until the bacterium is killed by the immune system.Most viral infections eventually result in the death of the host cell. The causes of death include cell lysis, alterations to the cell's surface membrane and various modes of programmed cell death. Some viruses cause no apparent changes to the infected cell.
Answer:
They are intermediate hosts.
Explanation:
Disease-transmitting insects are called vectors.
The life cycle of disease-causing pathogens is closely linked to the biology of the insect that carries it.
The symptoms of gongylonemiasis include hemorrhagic inflammation at the site the pathogen invades, followed by granulomatous tissue development that produces nodules in the invaded organ.
Some diseases transmitted by insects occur in both humans and other mammals because our differences in anatomy and physiology are not very different.
It is unlikely that clinical symptoms will occur in humans if the insect were the definitive host, because our biology is quite different from their biology, and the pathogen would be adapted to fulfill its entire life cycle in their body.
