Ecology is basically concerned with four levels of biological organisation. Which one of the following is the correct representation?

1.	Population$\to$Ecosystem$\to$Biome$\to$Landscape
2.	Communities$\to$Population$\to$Ecosystem$\to$Biome
3.	Organisms$\to$Population$\to$Communities$\to$Biome
4.	Species$\to$Ecosystem$\to$Communities$\to$Biome

Fitness of one species (measured in terms of intrinsic rate of increase) is significantly lower in the presence of another species during the interaction between

What is correctly explained using the given age pyramid?

Verhulst - Pearl logistic population growth is represented by

1. $\frac{\mathrm{dN}}{\mathrm{dt}}=\mathrm{rN}$
2. $\frac{\mathrm{dN}}{\mathrm{dt}}=\mathrm{rN}\left(\frac{\mathrm{K}-\mathrm{N}}{\mathrm{K}}\right)$
3. ${\mathrm{N}}_{\mathrm{t}}<mspace\; width="1em"></mspace>=<mspace\; width="1em"></mspace>{\mathrm{N}}_{\mathrm{o}}{\mathrm{e}}^{\mathrm{rt}}$
4. ${\mathrm{N}}_{\mathrm{t}}<mspace\; width="1em"></mspace>=<mspace\; width="1em"></mspace>{\mathrm{N}}_{\mathrm{o}}<mspace\; width="1em"></mspace>+\hspace{0.17em}\mathrm{I}<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>\mathrm{B}<mspace\; width="1em"></mspace>-\hspace{0.17em}\mathrm{E}<mspace\; width="1em"></mspace>-<mspace\; width="1em"></mspace>\mathrm{D}$

Select incorrect match with respect to population interactions where '+' sign for beneficial interaction, '-' sign for detrimental and 0 for neutral interaction.

     Species A         Species B       Name of interaction

1     (+)                     (-)                 Predation

2     (+)                     (-)                 Parasitism

3     (+)                     (0)                Commensalism

4     (+)                     (-)                  Amensalism

Interaction between sea anemone that has stinging tentacles and clown fish that lives among them, is an example of

1. Amensalism

2. Commensalism

3. Parasitism

4. Predation

In nature, a given habitat has enough resources to support a maximum possible number, beyond which no further growth is possible. This limit is known as

Match the following (column l with column ll)

1. a(iii), b(ii), c(i), d(iv)
2. a(iv), b(i), c(ii), d(iii)
3. a(iv), b(ii), (i), d(iii)
4. a(iii), b(i), c(ii), d(iv)

All given features are characteristic to parasites, except

The most observed circumstantial evidences in favour of Gause's principle is