A sedentary sea anemone gets attached to the shell lining of hermit crab. The association is
ectoparasitism
symbiosis
commensalism
amensalism
B.
symbiosis
This type of mutualisn to called protocooperation. In this type, the sea anemone grows on the back of the hermit crab. It protects the crab with the help of its nematocysts.
Ectoparasites live on the outside of host, e.g., human body louse. In this interaction, the parasite gets the benefit at the experise of the host.
Commensalism is an assotiation between organisms in which one or both the species are benefitted and neither species is harmed.
In amensalism one species is harmed, whereas the other is unaffected. Predation, parasitism and commensalism share a common characteristic, the interacting species live closely together.
A biologist studied the population of rats in a barn. He found that the average natality was 250, average mortality 240, immigration 20 and emigration 30. The net increase in population is
10
15
05
Zero
The· eyes of Octopus and eyes of cat show different patterns of structure, yet they perform similar function. This is an example of
homologous organs that have evolved due to convergent evolution
homologous organs that have evolved due to divergent evolution
analogous organs that have evolved due to convergent evolution
analogous organs that have evolved due to divergent evolution
Infection of Ascaris usually occurs by
drinking water containing egg of Ascaris
eating imperfectly cooked port
tse-tse fly
mosquito bite
Global warming can be controlled by
Reducing deforestation, cutting down use of fossil fuel
Reducing reforestation, increasing the use of fossil fuel
Increasing deforestation, slowing down the growth of human population
Increasing deforestation, reducing efficiency of energy usage
Which one of the following processes during decomposition is correctly described?
Fragmentation - Carried out by organisms such as earthworm
Humification - Leads to the accumulation of a dark coloured substance humus, which undergoes microbial action at a very fast rate
Catabolism - Last step in the decomposition under fully anaerobic condition
Leaching - Water soluble inorganic nutrients rise to the top layers of soil
During sewage treatment, biogases are produced, which include
methane, hydrogen sulphide and carbon dioxide
methane, oxygen and hydrogen sulphide
hydrogen sulphide, methane and sulphur dioxide
hydrogen sulphide, nitrogen and methane
In plant breeding programmes, the entire collection (of plants/seeds) having all the diverse alleles for all genes in a given crop is called
selection of superior recombinants
cross- hybridisation among the selected parents
evaluation and selection of parents
germplasm collection
The cell-mediated immunity inside the human body is carried out by
T-lymphocytes
B-lymphocytes
thrombocytes
erythrocytes
