In the equation, where r stands for
Intrinsic rate of natural increase
Death rate
Population density at time t
Carrying capacity
Carrying capacity
A.
Intrinsic rate of natural increase
Population growing in a habitat with limited resources show a lag phase, phase of acceleration and deceleration and asymptote phase, when the population density has reached the carrying capacity. It is known as Verhulst- Pearl Logistic Growth.
where, N = population density at time t
r = intrinsic rate of natural increase
K = carrying capacity
Which of the following statements about Productivity is true?
Primary productivity of all ecosystems is a constant
The annual net primary productivity of the whole of the biosphere is 17 billion tons (dry weight) of organic matter
Net primary productivity is the amount of biomass available for consumption by carnivores
Secondary productivity is defined as the rate of formation of new organic matter by decomposers .
Secondary productivity is defined as the rate of formation of new organic matter by decomposers .
The pioneer species in Xerarch and Hydrarch succession are respectively
Lichens and sedges
Lichens and rooted hydrophytes
Phytoplanktons and lichens
Lichens and phytoplanktons
Lichens and phytoplanktons
Which of the following statements does not apply to eutrophication?
It is the natural ageing of a lake by nutrient enrichment of its water
In a young lake the water is cold and clear and supports less life
The nutrients such as sulphur and phosphorus encourage the growth of aquatic organisms in the lake
Pollutants released by man radically accelerate the ageing process of a lake
Pollutants released by man radically accelerate the ageing process of a lake
According to Robert Constanza, 50% of the total cost for ecosystem services goes to
Recreation
Soil formation
Nutrient cycling
Climate regulation
Climate regulation
Which of the following statement(s) regarding energy flow is/are false?
I. The detritus food chain begins with dead organic matter.
II. In aquatic ecosystem, detritus food chain is the major conduit for energy flow.
III. In terrestrial ecosystem a larger fraction of energy flows through grazing food chain.
IV. Producers belong to the first trophic level of the food chain.
II and III only
III and IV only
I and IV only
I and II only
I and II only
The first recombinant DNA was constructed by linking an antibiotic resistant gene with the native plasmid of V
Escherichia coli
Salmonella typhimurium
Clostridium butylicum
Acetobacter aceti
Acetobacter aceti
The polymerase chain reaction1 (PCR) is a technique that is used for
in vivo replication of specific DNA sequence using thermostable DNA polymerase
in vitro synthesis of mRNA
in vitro replication of specific DNA sequence using thermostable DNA polymerase
in vivo synthesis of mRNA
in vivo synthesis of mRNA
Bioreactors are useful in
Separation and purification of a product
Processing of large volumes of culture
Micro-injection
Isolation of genetic material
Isolation of genetic material
Match the following and choose the correct combination from the options given.
Column I (Chemical compounds) | Column II (Example) |
A. Nitrogen base | 1. RNA |
B. Nucleoside | 2. Thymidylic acid |
C. Nucleotide | 3. Cytidine |
D. Nucleic acid | 4. Uracil |
A - 1; B - 2; C - 3; D - 4
A - 1; B - 3; C - 2; D - 4
A - 4; B - 3; C - 2; D - 1
A - 4; B - 1; C - 2; D - 3
A - 4; B - 1; C - 2; D - 3