Answer:
THE ANSWER ISSSSSSSSS HOST
Explanation:
 
        
                    
             
        
        
        
A.) Veins in the pulmonary circuit carry oxygen-rich blood 
red blood cells are used to circulate oxygen through out the body, thus it is true.
 
        
             
        
        
        
Answer:
- Oak trees: primary producers
- Caterpillars: primary consumers
- Blue Jays: secondary consumers
- Hawks: tertiary consumers
Explanation:
A trophic pyramid, also known as ecological pyramid or energy pyramid, is a graphic representation that shows the relationships between different types of organisms (i.e., producers and consumers) at the trophic levels of an ecosystem. The primary producers are autotrophic organisms that obtain energy from sunlight and chemical compounds from nonliving sources (e.g., photosynthetic plants, algae, etc). The primary consumers are organisms that eat primary producers (e.g., herbivores), while secondary consumers are organisms that eat primary consumers (e.g., omnivores). Moreover, tertiary consumers are predators and/or omnivores that eat secondary consumers (e.g., hawks). Finally, decomposers (e.g., bacteria) are organisms that obtain nutrients and energy by breaking down dead organic material (i.e., dead organisms) at all trophic levels into nutrients.
 
        
             
        
        
        
Answer:
Although more offsprings are produced by the process of external fertilization but the process of internal fertilization is more efficient as compared to external fertilization. This is because, in external fertilization, it is more difficult for the sperm to find the egg and fertilize it. Even after fertilization, it might be that the zygote gets eaten up by a predator. There are none such risks in internal fertilization. The zygote is protected during the internal fertilization which makes this process more efficient.