It is Xylem of the plants that help transport the water and other nutrients from the roots up through the plant. The phloem basically transport food synthesised by the plant but not the water.
        
             
        
        
        
Answer:
The small population of zooplankton have an unequal effect on the marine community.
Explanation:
According to this question, there are three trophic levels of organism in a lake as follows: non-native fish, zooplankton, and algae. However, due to the declination in the number of zooplanktons in the lake as they were fed on by the non-native fish, the algal population increased to form a BLOOM. 
This bloom of algal species can be attributed to the lack of zooplanktons, which represented the only herbivorous (plant eaters) organism in that community. Hence, their relatively small population have an unequal effect on the marine community. This means that the small population of zooplanktons caused an imbalance in the community and this is why ZOOPLANKTON is the keystone species in this scenario.
 
        
             
        
        
        
<h2>DNA hold an organisms hereditary information.</h2>
Explanation:
- DNA stands for deoxyribonucleic acid.
- DNA contains genes that are specific sequence of nucleotide that code some proteins or other gene products.
- Genes are specific to an organism and carry the hereditary information.
-  Genes are responsible for the trait or characteristic of an organism.
- DNA is the bearer of hereditary units for most organisms except in case of some Viruses.
- In viruses RNA holds the hereditary information.
 
        
        
        
Answer: B. 
Explanation:
The thermosphere is most directly affected by the Sun’s radiation.