Answer:
1,250,000 shrimps per m³
Explanation:
Population density refers to how dense an area is per unit area/volume, and it is calculated by dividing the number of individuals in that area (population) by the area/volume of that area. That is;
Population density = population (N)/volume
According to this question, a certain lake has a volume of about 480 m³ that harbors a 600 million of freshwater shrimp. This means that;
Population density of the lake = population of shrimps ÷ volume of lake
Population density = 600,000,000 ÷ 480
Population density = 1,250,000 shrimps per m³
 
        
             
        
        
        
Elderly people are most at risk
from minor trauma that results in serious spinal cord injury because of
preexisting degenerative vertebral disorders. Males are more prone to spinal
cord injuries than females but not as a result of preexisting disorder. This
may be related to an increased involvement in contact sports or a propensity to
participate in high risk activities. Neither females nor infants are at any
particular risk for spinal cord injuries.
 
        
             
        
        
        
Answer:
The correct answer will be option-B.
Explanation:
Deoxyribose nucleic acid or DNA is the genetic material of the organism which is made up of nucleotide monomer. The structure of DNA is made up of two strands of nucleotides coiled in a helical structure thus providing a double-helical shape to the structure.  
Each nucleotide of a strand is composed of a five-carbon sugar, phosphate group and nitrogenous bases. These molecules are arranged in anti-parallel fashion in DNA which provides the polarity to the DNA strand. One strand is read from the 5' to 3' direction whereas another form 3'to 5' direction.
Thus, Option-B is the correct answer.