Which of the following is a correct pair: 

1. Cuscuta – parasite

2. Dischidia – insectivorous

3. Opuntia – predator

4. Capsella – hydrophyte

Mycorrhiza is an example of:

1. Symbiotic relationship

2. Ectoparasitism

3. Endoparasitism

4. Decomposers

Two different species cannot live for a long duration in the same niche or habitat. This is:

1. Allen's law

2. Gloger's rule

3. Competitive exclusion principle

4. Weismann's theory

A male insect mistakes an orchid flower to be female due to its shape and performs the act of copulation and induces pollination. This is an example of:
1.  Mimicry
2.  Pseudocopulation
3.  Pseudopollination
4.  None

Inspite of interspecific competition in nature, which mechanism the competing species might have evolved for their survival?

Amensalism can be represented as:

1. Species A (–) : Species B (–)

2. Species A (+) : Species B (0)

3. Species A (–) : Species B (0)

4. Species A (+) : Species B (+)

In the exponential growth equation N_t =N₀e^rt, e represents :

1. The base of natural logarithms 

2. The base of geometric logarithms

3. The base of number logarithms

4. The base of exponential logarithms

The logistic population growth is expressed by the equation:

1. $\frac{dN}{dt}=rN\left(\frac{N-K}{N}\right)$

2. $\frac{dt}{dN}=Nr\left(\frac{K-N}{K}\right)$

3. $\frac{dN}{dt}=rN\left(\frac{K-N}{K}\right)$

4. $\frac{dN}{dt}=rN$

Which one of the following is most appropriately defined:

The impact of immigration on population density is: