BIOLOGY 1 Marks Question

4.  One organism is benefited, other is affected.

Parasitism is an interaction between two species in which one species (parasite) derives benefit while the other species (host) is harmed. For example, ticks and lice (parasites) present on the human body represent this interaction where in the parasites receive benefit (as they derive nourishment by feeding on the blood of humans). On the other hand, these parasites reduce host fitness and cause harm to the human body.

Stagnant water/Eutrophic/nutrient enriched water bodies/polluted with nutrients. 

1. Predation helps to check the ecological balance in nature.
2. Predation helps in maintaining species diversity as in abs.ce of predator there will be more interspecific competition.

1. Tilt of the earth on its axis.
2. Rotation of earth around the sun.

1. Variation in the intensity and duration of temperature.
2. Variation in precipitation.

1. Lichens formed jointly by an alga and fungus.
2. Termites harbouring cellulose digesting protozoans.

1. The mediterranean orchid, Ophrys and its pollinators (bumble bees and bees).
2. The fig species and its pollinator wasp.

1. In the curve (a) there is unlimited supply while (b) there are limited sources.
2. Curve (a).

1. Summer.
2. To survive from heat/ to escape from desiccation.

1. Biotic community is defined as a group of different populations living at one place and interacting with one another in several ways.
2. Biome is a major terrestrial biotic community characterised by distinctive live form, e.g., temperate deciduous forest, grassland etc.

1. Timing their foraging.
2. Migratory activities.
3. Reproduction.

1. Parasitism.
2. Mutualism.
3. Commensalism.
4. Brood parasitism.

1. Brood parasitism.
2. Commensalism.
3. Ectoparasitism.
4. Commensalism.

1. The removal or downward movement of soluble chemicals from soil by water is called leaching.
2. The response of organism to number and duration of day lengths is called as photoperiodism.

1. Organisms.
2. Populations.
3. Communities.
4. Biomes.

1. Initially the growth is slow.
2. The growth becomes rapid and the curve becomes steady due to environmental resistance.

1. 'r' is the intrinsic rate of natural increase
2. Increase in 'r' increases the population size while decrease in 'r' decreases the population size.

1. Daily.
2. Seasonal.
3. Periodic.