(i) The proportion of the age groups in a population is its age distribution attribute.
(ii) This determines the reproductive status of the population at the given time and is an indicator of the future population size.
(iii) Usually a rapidly growing population will have larger proportion of young individuals.
(iv) A stable population will have an even distribution of various age classes.
(v) A declining population tends to have a larger proportion of older individuals

No.	Tundra Biome	Taiga Biomes
1.	This is almost treeless plain in the northern parts of Asia, Europe, and North America.	Taiga is a forest of coniferous trees such as spruce, fir and pine.
2.	Winters are long with little daylight, summers are short, with long daylight hours.	Summer temperature ranges from 10octo 21oPc.
3.	Because of the severe winters, many of the animals are migratory. For E g: the many shore birds and water fowl such as ducks and geese, nest in the Tundra during the summer and migrate south for the winter.	Important migratory herbivores include moose, elk, deer and reindeer. Moose and reindeer migrate to the Taiga for winter and to Tundra for summers.

(i) The inherent tendency of all animal populations is to increase in number. But it does not increase indefinitely.
(ii) Once the carrying capacity of the environment is reached, population numbers remain static or fluctuate depending on environmental conditions.
(iii) This is regulated by many factors which are:
1. Density independent - Extrinsic factors
2. Density dependent - Intrinsic factors
(iv) Extrinsic factors include the availability of space, shelter, weather, food, etc.
(v) Intrinsic factors include competition, predation, emigration, immigration, and diseases.

S. No.	J shaped curve	S shaped curve
1.	When a population increases rapidly in an exponential fashion and then stops abruptly due to environmental resistance or due to sudden appearance of a limiting factor, they are said to exhibit J-shaped growth form,	Some populations, as in a population of small mammals, increase lowly at first then more rapidly & gradually slow down as environmental resistance increases where by equilibrium is reached and maintained
2.	Many insects show explosive increase in  number during the rainy season followed by their disappearance at the end of season.	Their growth is represented by s shaped growth curve.

S. No. Natality Mortality 1. It refers to the number of births per unit
population per unit time. e.g., per thousand
individuals per year in humans. It refers to the number of deaths per unit population per unit time. e.g., per thousand individuals per year in humans. 2. It adds new members to the population It removes members from the population 3. It increases the size of population. It decreases the size of population 4 Natality adds to population density Mortality reduces density of population 5 It maintains continuity of population It maintains health of population 6 It is high when population size is small and low when population size is large. Mortality is low when population
size is small and high when population size is large

Characters of biome 
(i) Location, geographical position (Latitude, Longitude)
(ii) Climate and physiochemical environment
(iii) Predominant plant and animal life
(iv) Boundaries between biomes are not always sharply defined. Transition or transient zones are seen as in case of grassland and forest biomes.

Hibernation:
Spending the winter in an inactive dormant state to escape in time, is called hibernation. E.g: Bears and Frogs.
Aestivation:
Spending the dry, hot period in an inactive state to escape in time is called aestivation .E.g: Snails and Fish.