1.Mature red blood cells of all mammals lack nuclei,with the exception of
those in the camel
2.most roots are positively geotropic but roots of mangrove plants grow away from gravity
the aquatic larval stage of American salamander can reproduce inspite of retaining its larval form
3 DNA is the hereditary material with the exception of some viruses such as tobacco mosaic virus TMV
4. A human being is clinically dead when there is no pulse that is no heart beat and his pupils are fixed and dilated ( no reaction to light).clinical death is not the same as biological death. Almost all the body cells remain alive for several hours after clinical death.this is why tissues and organs to be used for transplantation are removed within a few minutes after death
5.ciliates hitherto thought tobe immortal due their capacity for binary fission, are now found to age and die ,after a certain number of fissions
6. an amoeba divides into two cells, which in turn divide into two each and so on.when does an amoeba dhe? Bacteria divide every 15 to 20 minutes,the original losing its identity.when there is overcrowding ,bacterial cells die as a result of their own secretions. We can call this natural death
7/resurrection plants : some species of moss Selaginella grow on exposed rocks and have ability to survive dessication.when placed in water they revive and are hence called resurrection plants. Myrothamnus and craterostigma grow in highly arid regions of south Africa.dark brown dried up plants when receive rain the plants revive,their leaves become green and functional .in extreme dessication these plants appear dead but come to life when water is available.
By: ashwani kumar @vigyan tutorials. phagwara. 9646388266
2.most roots are positively geotropic but roots of mangrove plants grow away from gravity
the aquatic larval stage of American salamander can reproduce inspite of retaining its larval form
3 DNA is the hereditary material with the exception of some viruses such as tobacco mosaic virus TMV
4. A human being is clinically dead when there is no pulse that is no heart beat and his pupils are fixed and dilated ( no reaction to light).clinical death is not the same as biological death. Almost all the body cells remain alive for several hours after clinical death.this is why tissues and organs to be used for transplantation are removed within a few minutes after death
5.ciliates hitherto thought tobe immortal due their capacity for binary fission, are now found to age and die ,after a certain number of fissions
6. an amoeba divides into two cells, which in turn divide into two each and so on.when does an amoeba dhe? Bacteria divide every 15 to 20 minutes,the original losing its identity.when there is overcrowding ,bacterial cells die as a result of their own secretions. We can call this natural death
7/resurrection plants : some species of moss Selaginella grow on exposed rocks and have ability to survive dessication.when placed in water they revive and are hence called resurrection plants. Myrothamnus and craterostigma grow in highly arid regions of south Africa.dark brown dried up plants when receive rain the plants revive,their leaves become green and functional .in extreme dessication these plants appear dead but come to life when water is available.
By: ashwani kumar @vigyan tutorials. phagwara. 9646388266
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