Adaptations - class-VIII
Description: adaptations | |
Number of Questions: 61 | |
Created by: Garima Pandit | |
Tags: principles of ecology biodiversity environmental science chemistry plant biology biology morphology of flowering plants botany adaptations to different ecosystems the living world of plants vegetative morphology ecological adaptations, succession and ecological services the habitat of living adaptation |
Plants adapted to grow in shade are
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Psammophytes
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Sciophytes
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Mesophytes
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Xerophytes
Plants growing in bright light are called as sun plants or heliophytes, while plants growing in partial shade or low light intensity are called as shade plants or sciophytes.
A succulent xerophyte is
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Capparis
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Calotropis
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Agave
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None of the above
In succulent xerophyte, plants have fleshy organs, where water and mucilage are stored. Depending upon the organ, where succulence occurs, the succulents show chylocauly, i.e., fleshy stem, e.g., Opuntia, Euphorbia, Asparagus; chylophylly ie fleshy leaves, e.g., Agave, Aloe or chylorhizy, i.e., fleshy roots, e.g., Asparagus.
Mechanical tissue is best developed in
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Hydrophytes
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Halophytes
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Xerophytes
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Mesophytes
Plants living in dry conditions are called as xerophytes. These plants show many morphological and structural adaptations to survive in dry conditions. In stem the mechanical tissue is well developed and also bark is well developed to retain water
Myrmecophily is an association between higher plant and.
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Bacteria
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Fungi
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Blue-green algae
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Ants
The vegetation of Rajasthan is
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Arctic
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Alpine
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Deciduous
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Xerophytic
Xerophytes are plants of dry habitats, where the environment favours higher rate of transpiration than the rate of absorption.
Which one is not a trait of xerophytes?
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Thick cuticle
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Sunken stomata
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Aerenchyma
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Well developed mechanical tissue
Hydrophytes possess special air storage parenchyma tissue, called as aerenchyma. It makes different parts of hydrophytes, light, spongy and flexible. It makes oxygen produced during photosynthesis, available to roots and other non photosynthetic regions. It can also help in exchange of gases with the atmosphere through stomata present in emerged regions of plants. Xerophytes show structural adaptations to discourage water loss through transpiration and increase water absorption. Such adaptations include thick cuticle, sunken stomata, well developed vascular tissue etc.
The waxy surface of floating leaves of the hydrophytes prevents
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Respiration
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Photosynthesis
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Transpiration
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Clogging of stomata
Hydrophytes are water loving plants. The hydrophytes with floating leaves have large leaves, stomata and waxy coating on the upper surface. The waxy coating prevent wetting and clogging of stomata.
Which one of the following is correct matching of a plant, its habit and the forest type where it normally occurs
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Prosopis, tree, scrub
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Saccharum, grass, forest
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Shorea robusta, herb, tropical rain forest
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Acacia catechu, tree, coniferous forest
Plants like Rhizophora and Avicennia grow on the sea shores under saline conditions. For this they have special roots for respiration which are called
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Floating roots
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Pneumatophores
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Climbing roots
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Prop roots
Pneumatophores are specialized root structures that grow out from the water surface and facilitate the aeration necessary for root respiration in hydrophytic trees such as many mangrove species (e.g., Avicennia germinans and Laguncularia raecemosa), bald cypresses, and cotton (Tupelo) gum (Nyssa aquatica). So, the correct option is "B" (Pneumatophores).
Choose the feature not associated with organism found in tropical deserts
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Small body size
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Large surface area relative to their volume
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Large body extremities
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Small surface area relative to their volume
Tropical desert areas are those where there is scarcity of water and extensive heat. Organisms in those areas adapt to survive in that ecological condition. Adaptations like thorns and succulents in flora helps the plants to survive without plenty of water. The leaves and stems undergo modification to conduct photosynthesis in less available water. Animals like frogs, rabbits, snakes, camels, etc. also go through modification in their characteristics to ensure their survival. Large surface of an any organism can lead to radiation of more body heat per unit of mass which can be fatal. Hence, such adaptations is not seen in organisms present in tropical desert.
Cuticle in xerophytes acts as a barrier to evaporation and also the shiny surface reflects heat and so lowers temperature.
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True
-
False
Find the correct match.
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Halophyte - Wheat
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Xerophyte - Mustard
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Geophyte - Tomato
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Hydrophyte - Pistia
The sun loving plants are referred to as
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Halophytes
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Heliophytes
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Heterotrophs
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Sciophytes
Green plants are absent in deep sea. Why?
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Light is absent
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High pressure
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Low temperature
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Great depth
Effect of $O _{3}$ in plants, involve:
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Stomata burning
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Oxidizing burning
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Reduced survival
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All of above
Most animals and plants can grow with pH, between
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4 and 9
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5 and 9
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6 and 9
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7 and 9
_________ plants have flattened leaf-like stems to carry out photosynthesis.
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Prickly pear
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Potato
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A & B
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None of the above
In Opuntia (prickly pear), the stem is modified to a flattened green structure to perform the function of leaves. Leaf-like flattened modified stems are called phylloclades.
Nitrates, phosphates and sulphates are plants
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Disease
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Pollutants
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Nutrients
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Organic pollutants
Naturally HCs found in atmosphere are produced from the
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Plants
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Soil
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Lithosphere
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Crust
The source of atmospheric oxygen is
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Nitrogen cycle
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Green Plants
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Water
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Carbon Cycle
Cuticular transpiration is observed mainly in?
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Xerophytes
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Herbaceous plants
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Trees
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Shrubs
What reduces amount of light reaching leaf?
-
Sulfur oxide emission
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Carbon dioxide
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Dust and Smog
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Nitrogen
Which of the following is the major adaptation for a plant to survive in the xerophytic conditions?
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Long tap root
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Lack of stomata
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Spines
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Stipular leaves
CactI are among the most drought-resistant plants on the planet, due to their absence of leaves, shallow root systems, ability to store water in their stem, spines for shade and waxy skin to seal in moisture. Xerophytes can have smaller leaves or fewer branches than other plants. An example of leaf surface reduction are the spines of a cactus. Spines also protect the plants from animals and collect moisture too.
Some plants have a habit of harbouring ants to save the plants from damage by other animals which is known as
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Entomophily
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Myrmacrophily
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Anemophily
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Hydrophily
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Zoophily
Myrmecophily is the term applied to positive interspecies associations between ants and a variety of other organisms such as plants, other arthropods, and fungi. Myrmecophily refers to mutualistic associations with ants, though in its more general use the term may also refer to commensal or even parasitic interactions. The term myrmecophile is used mainly for animals that associate with ants.
Halophytes can grow on physiological dry soil due to
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Dry soil
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Excessive humidity outside
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Excessive salts in plants
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Excessive salts in water
Halophytes grow in physiologically dry soil. The soil is having water but the soil solution has a high concentration of salts. Thus, the water is not easily available to plants, because water flows from a region of high water potential to a region of low water potential.
Which one is a xerophyte?
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Capparis
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Lotus
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China Rose
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Casuarina
Capparis decidua (family Capparidaceae) is commonly known as kair. It is
distributed throughout the arid regions of India and other countries. Kair is a caducous plant, so in the foliage condition mainly stem and fruits are common. It is also known as Capparis aphylla.
Since the plant is xerophytic, it is generally found in dessert area and is highly draught resistant plant, which can survive for long. Tribal people prepare pickle from the fruits of kair.
The plants in which vascular tissues are absent and well developed aerenchyma is present are
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Xerophytes
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Halophytes
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Hydrophytes
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Mesophytes
Hydrophytes are water loving plants and grow in aquatic environments. In these plants mechanical tissue is absent. Xylem is poorly developed or absent. Hydrophytes possess special air storage parenchyma, called as aerenchyma. It makes plant parts light, spongy and flexible.
Succulent xerophytes are likely to be found in
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Tropical rain forest
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Deciduous forest
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Desert
-
Tundra
Xerophytes are the plants that has adapted to survive in an environment with little liquid water, such as a desert or an ice- or snow-covered region in the Alps and Arctic regions. Succulents plants stores water. They have mucilage to retain water. Stomata are sunken and usually open only during nights.
A plant growing on a forest floor
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Has shallow roots
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Requires low light
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Has a deep tap root
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Requires strong light
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Requires moist soil
Typical plants that are found on the forest floor include a variety of ferns, mangrove trees, and vines. The canopy of trees spread their leaves to attract as much sunlight. Though the forest floor is the principal sites of decomposition, there is a stiff competition for sunlight and nutrients. The plants that occupy the forest floor are ones that require low light as they are adapted to grow under conditions of low light availability and have large dark green leaves to absorb as much sunlight.
The features of the xerophytic plant leaves are:
(i) Leathery surface
(ii) Large surface area
(iii) Waxy cuticle
(iv) Sunken stomata on upper epidermis
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(i), (ii) and (iv)
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(i) and (iii)
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(i), (iii) and (iv)
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(i) and (iv)
Xerophytes are plants of dry habitats, which are faced with the problem of more water loss through transpiration than is water available from soil, e.g., Acacia, Casuarina etc.
In these plants leaves or leaflets are often small, vertical, thick and leathery. Cuticle is thick and waxy. Stomata are sunken and restricted to lower surface of leaf.
The root pockets are present instead of root caps in
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Utricularia
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Eichhornia
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Hydrilla
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Limnophylla
- The root cap protects the growing tip of roots from soil and hard rock surface.
- As hydrophytes are generally aquatic plants, no such protection is needed for their roots.
- As a result of which root cap is absent in hydrophytes.
- In given options all are aquatic plants but utricularia, hydrilla and Limnophylla are rooted submerged plants there root are present in soil.
- Eichhornia is free floating aquatic plant and there root arr floating in water so they don't have the need of root cap they have root pockets.
- Option B is correct here.
Which one lacks both roots and stomata?
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Hydrophytes
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Mesophytes
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Hygrophytes
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Halophytes
Hydrophytes are water loving plants. Stomata are absent in submerged hydrophytic plants. But floating hydrophytes have stomata on upper surface. e.g., lotus. Exchange of gases occurs through general surface in submerged hydrophytes. Emergent hydrophytes possess special air storage parenchyma called aerenchyma. It makes their different parts light, spongy and flexible. It can also help in exchange of gases with the atmosphere through stomata present in emergent regions. Roots of hydrophytes are poorly developed or completely absent in Wolffia.
Type of plants having adaptations to check transpiration is
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Xerophytes
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Lithophytes
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Halophytes
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Epiphytes
Xerophytes are the plants of dry habitats, where the environment favours higher rate of transpiration than the rate of absorption. Xerophytes have various adaptations to check water loss and increase water absorption.
One of the following is not true for hydrophytes.
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Vessels are usually absent.
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Trachieds are absent.
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Cuticle is poorly developed.
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Air chambers are well developed.
In hydrophytes, generally xylem is poorly developed. Tracheids are developed but vessels are completely absent. Hydrophytes possess special air storage parenchyma called aerenchyma. Cuticle is poorly developed.
Excessive aerenchyma is characteristic of
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Hydrophytes
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Xerophytes
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Mesophytes
-
Heliophytes
Hydrophytes possess special air storage parenchyma tissue, called as aerenchyma. It makes different parts of hydrophytes, light, spongy and flexible. It makes oxygen produced during photosynthesis, available to roots and other non photosynthetic regions. It can also help in exchange of gases with the atmosphere through stomata present in emerged regions of plants.
Submerged hydrophytes exchange gases through
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Stomata
-
Hydathodes
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Lenticels
-
General surface
Exchange of gases occurs through general surface in submerged hydrophytes.
Crystal sand found in Atropa cells is made of
-
Calcium oxalate
-
Calcium carbonate
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Silica
-
Silica and iron
- Minerals crystals are found in plant cell walls in the form of calcium oxalate, carbonate or silica.
- Calcium oxalate occurs in the form of a mass of crystals around a cellulosic core in few plants.
- Crystal sand is the calcium oxalate deposition in cells in the form of powdery mass and is seen in Atropa.
- So, the correct answer is 'Calcium oxalate'.
Raphides are formed of
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Calcium oxalate
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Calcium carbonate
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Sodium chloride
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Sodium carbonate
- Minerals crystals are found in plant cell walls in the form of calcium oxalate, carbonate or silica.
- Calcium oxalate occurs in the form of a mass of crystals around a cellulosic core in few plants.
- Calcium oxalate crystals occur in the form of needle-shaped in few plant cells and are called raphides.
- Eg- Water hyacinth.
- So, the correct answer is 'Calcium oxalate'.
Study of genetic composition of population in relation to habitat is called
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Genecology
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Genetics
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Eugenics
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Euthenics
______ has glandular hair.
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Calotropis
-
Tobacco
-
Lemon
-
Yucca
There
are various defense mechanism seen in plants. These are thorns,
spines, prickles, glandular hair, stinging hair, alkaloids,
tannins, raphides, etc. Tobacco has glandular hair for its
defense. Glandular hair with sticky substances protect it from
outer agencies. Lemon has thorns to protect itself from its
enemies. Yucca has pointed spines at the leaf ends to
protect itself from enemies.
Calotropis is
known as milkweeds because of the latex they produce. Thus,
the correct answer is 'Tobacco.'
Dry scales of onion possess in their cells
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Raphides
-
Prismatic crystals
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Sphaeraphides
-
Crystal sand
A. Calcium oxalate crystals occur in the form of needle-shaped in few plant cells and are called raphides.
-
Eg- Water hyacinth.
B. Calcium oxalate in the form of rod-like or cubicle shaped in few plant cells and are called prismatic crystals.
-
Eg- dry scales of onions.
C. Calcium oxalate crystals occur in the form of star-shape in plant cells and are called sphaeraphides.
-
Eg- phylloclades of Colocasia.
D. Calcium oxalate is deposited in the leaves within the vacuoles during early developmental stages in plants is called crystal sand. Eg- Beet root
So, the correct answer is 'Prismatic crystals'.
Which one of the following plant species is NOT a sand binder in the semi arid region?
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Salvadora indica
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Calotropis procera
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Saccharum munja
-
Saccharum spontaneum
Which one of the following is an example of a plant adapted to highly saline coastal conditions?
-
Sonneratia acida
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Anaardium occidentale
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Taxus baccata
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Gnetum gemon
Which one of the following is the earliest land plant?
-
Rhynia
-
Homea
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Cordite's
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Cook Sonia
Which of the following pairs of plant categories and habitat types are correctly matched?
a. Sociophytes- Shady
b. Heliophytes - Sunny
c. Psammophytes - Sandy
Select the correct answer using the codes given.
-
$1, 2$ and $3$
-
$1$ and $2$
-
$1$ and $3$
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$2$ and $3$
Which one is concerned with the temporary adaptation ?
-
Phytomelanin
-
Melanin
-
Tannin
-
Anthocyanin
In which one of the following geological periods did the first land plants appear?
-
Precambrian
-
Permian
-
Silurian
-
Carboniferous
Finely dissected leaf may be an adaptation of
-
xerophytes
-
psammophytes
-
halophytes
-
hydrophytes
Many hydrophytes have production of different forms of leaves in the same plant i.e., heterophylly. In submerged aquatics with free-floating aerial leaves, the submerged leaves are generally linear, ribbon-shaped or finely dissected while the aerial leaves are complete and rounded or lobed.
Which one of the following sets consists only of xerophytes plants?
-
Suhabool, Teak, Eucalyptus, mango
-
Baman, Acacia, Ziziphus, teak
-
Safflower, eucalyptus, asparagus, acacia
-
Acacia, prosopis, ziziphus, opuntia
Read the following statements about adaptations in desert plants and select the correct ones.
(i) They have a thick cuticle on their leaf surface
(ii) They have stomata present in deep sunken pits.
(iii) They use CAM pathway for photosynthesis.
(iv) They have flattened stems and large sized leaves.
(v) Their stomata remain closed during the day.
-
(i), (ii) and (iii)
-
(ii), (iii) and (v)
-
(i), (ii) and (iv)
-
(i), (ii), (iii) and (v)
The correct sequence of plants in hydrosphere is :
-
$Oak \rightarrow Lantana \rightarrow Volvox \rightarrow Hydrilla \rightarrow Pistia \rightarrow Scirpus$
-
$Oak \rightarrow Lantana \rightarrow Scirpus \rightarrow Pistia \rightarrow Hydrilla \rightarrow Volvox $
-
$Volvox \rightarrow Hydrilla \rightarrow Pistia \rightarrow Scirpus \rightarrow Lantana \rightarrow Oak$
-
$Pistia \rightarrow Volvox \rightarrow Scirpus \rightarrow Hydrilla \rightarrow Oak \rightarrow Lantana$
Plants which grow in shade are called
-
Sciophytes
-
Heliophytes
-
Oxylophytes
-
Epiphytes
Resource partinotiong can only take place when
-
Species have different feeding manner
-
Species only have different foraging manner.. no matters feeding type different or same
-
Different fedding and foraging time
-
None
Resource partitioning is the phenomenon of evolutionary changes seen in species in response to the selection pressure generated by interspecific competition. Due to this, no two organisms within the same species can coexist in the same niche if they have same resources. They have different foraging manner whether feeding type is different or same. Example of resource partitioning involves two tigers present in their own territories or niches and defending it from other tigers.
Excessive aerenchyma tissues in the plants is mainly an adaptation for.
-
Xerophytes condition
-
Hydrolytic condition
-
Epiphytic condition
-
Niesophytic condition
The most effective defence of plants against herbivores are
-
Morphological
-
Chemical
-
Temporal
-
Developmental
To counter the herbivore attack, plants produce specialized morphological structures or secondary metabolites and proteins that have toxic, repellent effects on the herbivores. Plants confront the herbivores both directly by affecting host plant preference or survival and reproductive success (direct defense), and indirectly through other species such as natural enemies of the insect pests (indirect defense). Direct defenses are mediated by plant characteristics that affect the herbivores biology such as mechanical protection on the surface of the plants (e.g., hairs, trichomes, thorns, spines, and thicker leaves) or production of toxic chemicals such as terpenoids, alkaloids, anthocyanins, phenols, and quinones) that either kill or retard the development of the herbivores.
Submerged hydrophytes have commonly dissected leaves for
-
Decreasing surface area
-
Increasing surface area
-
Reducing effect of water currents
-
Both B and C
The submerged leaves are often highly dissected or divided. This has the advantage of creating a very large surface area for absorption and photosynthesis. It also minimises water resistance and hence, potential damage to the leaves since moving water (currents and waves) can be damaging to the leaves of the plant.
In xerophytes, photosynthesis, often occurs through
-
Root
-
Modified stem
-
Stomata
-
Scaly leaves
Xerophytes are plants, that have small amount of water or moisture, so they have adaptations that allow them to survive in these harsh conditions. These plants are like cactus and other succulents are typically found in deserts.
One of the advantages of growing chilli plants between two rows ofgreen gram plants, is that
-
Chilli plants are protected by the shade of dhal plants
-
Nitrogenous fertiliser prepared by green gram plants can be utilised
by chilli plants -
Chilli plants get water from green gram plants
-
Dhal plants are protected from pests in the presence of chilli plants
Which one of the following is correct matching of a plant, its habit and the forest type where it normally occurs?
-
Prosopis, tree, scrub
-
Saccharum, grass, forest
-
Shorea robusta, herb, tropical rain forest
-
Acacia catechu, tree, coniferous forest
The bats are able to fly in dark since their mouth produce?
-
Sound waves
-
Ultrasonic waves
-
Infrared rays
-
Ultraviolet rays
The bats are able to fly in dark since their mouth produce
-
Sound waves
-
Ultrasonic waves
-
Infrared rays
-
Ultraviolet rays