Post on 19-Feb-2017
Chapter 15 (2nd year)
Chapter 15 (2nd year)
homeostasis
Environment
It can be defined as the surroundings or conditions in which a person, animal, or plant lives or operates.
Environment may be1: external environment2: internal environment
Homeostasis
It can be defined as the protection of internal environment from the harms of fluctuations in external environment is called as homeostasis
Osmoregulation
It can be defined as the mechanism of regulation , generally between organism and its environment , of solute and the gain and loss of water is osmoregulation
Thermoregulation
It can be defined as maintenance of internal temperature within a tolerable range is designated as thermoregulation.
Excretion
It can be defined as the process in which nitrogenous wastes are removed from the body is called as excretion
Control system
Water relations of cell
Osmoregulation in plants
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Distribution of plants according to different habitats
Hydrophytes Extensive stomata are present.They have very large leaves to transpire water excessively.Example: Water lilyMesophytes They have moderate water availabilityStomata are kept open to promote transpiration while in restricted supply of water, stomata are closed.Example. Brassica . Mango etc.xerophytes They have thick small leaves to reduce water lossThick waxy cuticle is present Stomata are on the lower surface of leaves, present in depressions.They have thick stem to store water, during rainy season.Some plants shed their leaves to restrict transpiration , completely.Example Cactus
Hydrophyte
Waterlily
Mesophytes
Rose Plant
Xerophytes
Cactus
Osmoregulation in animalsOsmoreconformers Osmoregulators
Osmoconformers
Their internal and outer water solute balance is isotonicSo they do not need to regulate it actively.Examples: invertebrates, including starfish and jelly fishAmong the vertebrates the osmoconformers are, hagfish , sharks, skates
Paramecium Contractile vacuole for osmoregulation
Terrestrial environment.
Kangroo rat
Excretion In plantsIn animals
Excretion in plantsBy:LeavesTrunkRootsBulbBy crystal formationEbony formation
Bulb of Blue bell flower
conifersRelease waste compounds in soil.
Rasins , latex, in trees
Excretophore
Excretory leaf and chlorosis in Leaves are different.
Nature of excretory products in animals
Urea cycle.
2 ammonia and 1 Carbon dioxide combine to form 1 urea molecule,
Excretion in planariaFlame cells.* protonephridium
Excretion in earthworm Metanephridium
Excretion in cockroach
Liver SynthesisStorageDetoxificationConversionrecycling
Skin as osmoregulatory organ
Sebaceous glandsSweat glands