Both, hydrarch and xerarch successions lead to:
1. Excessive wet conditions
2. Medium water conditions
3. Xeric conditions
4. Highly dry conditions

Which one of the following animals may occupy more than one trophic levels in the same ecosystem at the same time?

1. Frog 

2. Sparrow

3. Lion 

4. Goat

The breakdown of detritus into smaller particles by earthworm is a process called:
1. Catabolism
2. Humification
3. Fragmentation
4. Mineralisation

''Good ozone'' is found in the:
1. Ionosphere
2. Mesosphere
3. Troposphere
4. Stratosphere

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 a wrong matching of a microbe and its industrial product, while the remaining three are correct?
1. Aspergillus niger – citric acid
2. Yeast – statins
3. Acetobacter aceti – acetic acid
4. Clostridium butylicum – lactic acid

Read the following statement having two blanks (A and B):

''A drug used for ______ (A)___ patients is obtained from a species of the organism ______ (B)___ ''. The one correct option for the two blanks is:

Common cold is not cured by antibiotics because it is:
1. not an infectious disease
2. caused by a virus
3. caused by a Gram-positive bacterium
4. caused by a Gram-negative bacterium

Read the following four statements (A-D) and find out certain mistakes in two of them:

Which of the two statements has mistakes?
1. Statements (A) and (B)
2. Statements (B) and (C)
3. Statements (C) and (D)
4. Statements (A) and (C)

Silencing of mRNA has been used in producing transgenic plants resistant to: