Question 1

How is population density calculated?

Accepted Answer

Population density is the number of individuals in a population divided by the area it occupies at a given time. In this lab, 40 individuals spread across 100 square metres give a density of 0.4 individuals per square metre.

Question 2

What is the difference between a population count and natality?

Accepted Answer

A population count is the number of individuals present at a particular time, whereas natality is the number of births per unit time. To calculate an observed natality rate, the birth events must be divided by the stated observation interval.

Question 3

What is mortality?

Accepted Answer

Mortality is the number of deaths in a population per unit time. Like natality, it is a rate rather than the number of individuals currently alive.

Question 4

What do the axes of an age pyramid represent?

Accepted Answer

The vertical axis represents age groups and the horizontal axis represents population number. When sexes are shown separately, the two sides are identified as male and female.

Question 5

How are age pyramids classified?

Accepted Answer

NCERT classifies them as expanding, stable and declining. An expanding pyramid has a broad base, a stable pyramid has nearly equal pre-reproductive and reproductive groups with a narrower older group, and a declining pyramid has a relatively narrow base and broader upper portion.

Population Attributes 3D Lab — Density, Natality, Mortality & Age Pyramid

About this lab

Practice