In a sea shore, the benthic animals live in sandy, muddy and rocky substrata and accordingly developed the following adaptations.
(a) Burrowing
(b) Building cubes
(c) Holdfasts/peduncle
Find the suitable substratum against each adaptation.
In a sea shore, water current restrict distribution of organisms. In streamed areas of ocean, animals are strong swimmer or possess attaching organs such as peduncle, or live under stone, in burrows etc.
Burrowing animals like tubeworm, Nerlies are strong swimmer. Burrowing, building cubes and holdfast or penduncle adaptation are found in sandy, muddy and rocky substratum respectively.
Categorise the following plants into hydrophytes, halophytes, mesophytes and xerophytes. Give reasons for your answers.
(a) Salvinia
(b) Opuntia
(c) Rhizophora
(d) Mangifera
(a) Salvinia is a hydrophytes - Partially or completly submerged in water.
(b) Opuntia is a xerophyte - Dry habitat succulent leaves.
(c) Rhizophora is a halophyte - Saline habitat
(d) Mangifera is a mesophyte - Terrestrial habitat.
In a pond, we see plants which are free-floating; rooted-submerged, rooted emergent rooted with floating leaves. Write the type of plants against each of them.
$$ \begin{array}{ll|l} \hline & \text { Plant Name } & \text { Type } \\ \hline \text { (a) } & \text { Hydrilla } & \\ \text { (b) } & \text { Typha } & \\ \text { (c) } & \text { Nymphaea } & \\ \text { (d) } & \text { Lemna } & \\ \text { (e) } & \text { Vallisneria } & \\ \hline \end{array} $$(a) Hydrilla is submerged hydrophyte
(b) Typha is rooted emergent
(c) Nymphaea is rooted with floating leaves
(d) Lemna is free floating hydrophyte
(e) Vallisnaria is rooted submerged hydrophytes.
The density of a population in a habitat per unit area is measured in different units. Write the unit of measurement against the following
(a) Bacteria .............
(b) Banyan .............
(c) Deer .............
(d) Fish .............
The density of population per unit area is measured in following units
(a) The density of a bacterial population in a habitat per unit area is measured in volume/number unit.
(b) Biomass/area/region is measuring unit for density of population of banyan.
(c) Number/area is measuring unit for the density of population of deer.
(d) Weight/area is measuring unit for density of population of fish.
(a) Label the three tiers 1, 2, 3 given in the above age pyramid.
(b) What type of population growth is represented by the above age pyramid?
(a) The three tiers are to be labelled as
(i) Pre-reproductive phase
(ii) Reproductive phase
(iii) Post-reproductive phase
(b) The given age pyramid represents the expanding type of population growth.