Question

model 2 - survivorship curves

1. refer to model 2.

a. what does the x - axis on the graph in model 2 represent?
b. which type of organism shows a steady decline in its population at all life stages?

Explanation:

a. The x - axis labels in the model (Newborn, Pre - reproductive age, Reproductive age, Post - reproductive age) clearly indicate that it represents the age of the organism.
b. Type II organisms (like rodents) have a relatively constant mortality rate throughout their life stages, which is shown by a steady decline in the number of survivors (y - axis) as age (x - axis) progresses.

Answer:

a. The age of the organism.
b. Type II organisms.