Which of the above represents the increase or decrease of population?

Question

i. Which of the above represents the increase or decrease of population? 

ii. If N is the population density at time t, then what would be its density at time (t+1)? Give the formula. 

iii. In a barn there were 30 rats. 5 more rats enter the barn and 6 out of the total rats were eaten by the cats. If 8 rats were born during the time period under consideration and 7 rats left the barn, find out the resultant population at time (t+1). 

iv. If a new habitat is just being colonized, out of the four factors affecting the population growth, which factor contributes the most?

Answer 1

a. a and d represents increase of population and b and c represent decrease of population.

b. N_t+1 = N_t + [(B + I) – (D + E)]

c. Here, N_t = 30; I = 5; E = 7 ; D = 6; B = 8

Putting the value in N_t+1 = N_t + [(B + I) – (D + E)]

N_t+1 = 30 + [(8 + 5) – (6 + 7)]

= 30 + [13 – 13] 

= 30 + 0 

= 30 rats

d. Immigration contributes the most.