Which of the following is not a characteristic of climax community?

• Wide niche   

• Complex food web  

• Low resilience  

• Inter-biotic nutrients dependence  

In abandoned area first nitrogen fixing communities arrives and carry out nitrogen fixation, later on this community is replaced by non-nitrogenous fixing species. In the mechanism of succession this is in general agreement according to

• Facilitation

• Tolerance

• Inhibition

• Adaptation  

23.

Which is most favorable for maximum sustainable harvesting of resources?

• Major part of population is near or around the carrying capacity   

• Population is half of the carrying capacity   

• Population is one fourth below the carrying capacity

• Population has slow doubling time  

Release of nutrients, oxidants or electron donors into the environment to stimulate naturally occurring microorganism to degrade a contaminant, is referred to as

• Bio‐stimulation

• Phytoremediation

• Bio‐augmentation

• Bio‐remediation

During the early origin of earth oxygen was absent in environment. Later on the oxygen increases and reached to present level. The main source of oxygen was

• Photosynthesis

• Released from CaCO₃    

• Escape of CO₂ to environment    

• Escape of oxygen from internal sources   

Optimum temperature for growth of extreme theromophiles is

• 0°C

• 20°C

• 50°C

• Over 80°C

Largest reservoir of carbon is

• Atmosphere

• Ocean sediments

• Carbonate and silictae rocks

• Inorganic carbon in earth mantle

The following figure shows McArthur and Wilson’s equilibrium model of biota on a single island

In this figure, term A, B, C and D in order are

• Extinction, immigration, equilibrium number of species, size of special pool

• Immigration, extinction, equilibrium number of species, size of species pool

• Extinction, immigration, size of species pool, equilibrium number of species

• Immigration, extinction, size of species pool, equilibrium number of species

The total variancein a phenotypic character can be split into two components geic (V_G) and environmental (V_E). The heritability of a phenotypic trait can be expresses quantitatively as heritability cofficient (h²) which is calculated as h²=

• V_G- V_E

• V_E/V_G

• V_G/ V_G + V_E

• V_G/ V_G - V_E

In one study, a group of 5 day rat pups were fed for 3 weeks a diet A and the pups gained weight by 300%. In a second study, when the same diet fed for 3 weeks to rats of 350 gms, they do not gain weight significantly. In a third study, a diet B was fed to 250‐350 gms rats and its was observed that they delivered normal pups after five weeks. Based on these observations which of the following statements is correct?

• Diet A facilitates weight gain than diet B

• Diet B facilitates pregnancy and child breaing

• More control experiments are to be conducted for definitive conclusion.

• Diet A is more energy containing than diet B. Hence, is quantity should be reduced.