Answer:
large mammals such as gorillas
Explanation:
The survivorship curves refer to the graphical representation of the proportion of the fraction of survivors or the individuals at a given age.
There are three types of survivorship curves which can be constructed by studying the life history of the organisms.
The type I survivorship curve is the curve which can be formed with the organism which has a high survival rate at the younger and middle age and high death rate at the older age. The type I curve can be characterised by its convex shaped. The type I is showed by the large mammals like gorilla, humans and many others.
Thus, large mammals such as gorillas are the correct answer.
 
        
             
        
        
        
Answer: 
The biologist is studying about the ecological community.
Explanation:
The ecological community refers to the community in which population of different types of species survives together. As the biologist is observing about the interaction of different populations of Pennsylvania region, it can be inferred that the he is studying about the ecological community of Pennsylvania region. 
The population surving in the community interact with each other through different modes of interaction. It may either parasitic, or mutual, or competitive or predication or commercialism. 
 
        
             
        
        
        
Acclimation is the physiological response or phenomenon which is responsible for survival of salmon in fresh water and salt water.
When a young salmon starts its sea journey it travels wide distances in search for oceans completing a leg of their journey. They travel back to home streams for spawning. This survival in different osmotic potentials and salinity is due to osmoregulation and acclimation. System of salmon detects saline change and instigates a negative feedback system to the body water concentration. Similar feedback works contrastingly when salmon is in fresh water or marine streams of water. 
Hence, the physiological response occuring in salmon is acclimation.
Learn more about osmoregulation here: 
brainly.com/question/11334419
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