Mosses are of great ecological importance because of
its contribution to prevent soil erosion.
its contribution in ecological succession.
its capability to remove CO from the atmosphere.
both (a) and (b)
Correct Answer :
D. both (a) and (b)
Mosses along with lichens are the first organisms to colonise rocks and hence, are of great ecological importance. They decompose rocks making the substrate suitable for the growth of higher plants. Since mosses form dense mats on the soil, they reduce the impact of falling rain and prevent soil - erosion.
Related Questions
The heterosporous pteridophyte belonging to the class lycopsida is
Selaginella
Psilotum
Equisetum
Pteris
Fusion of two gametes which are dissimilar in size is termed as _______.
isogamous
oogamous
anisogamous
agamous
Which of the following group of plant is being described by the given statements ?
(i) They are plants in which the ovules are not enclosed by any ovary wall and remain exposed before and after fertilization.
(ii) The giant red wood tree Sequoia is one of the tallest tree species of the group.
(iii) The roots are generally tap roots.
(iv) They are heterosporous and they produce haploid microspores and megaspores.
Algae
Bryophytes
Gymnosperms
Pteridophytes
Which of the following statement(s) is/are correct about gemmae ?
(i) These are specialised structures by which asexual reproduction take place in liverworts.
(ii) They are green, multicellular and asexual buds.
(iii) They develop in small receptacles called gemma cups.
(iv) They detach from parent body and germinate to form new individuals.
(i) and (ii)
(ii) and (iii)
(i), (ii) and (iii)
All of these
Which of the following statement(s) is/are correct?
(i) Green algae are the members of chlorophyceae.
(ii) Brown algae are found primarily in marine habitates
(iii) Some red algae are found in fresh water, mostly occur in salt water, some are in brackish water.
(iv) The food in red algae is stosed as floridean starch.
(v) Red alga may occur in both well-lighted regions close to water-surface and also at great depths in oceans where light penetration is little.
(i) and (v) only
(ii), (iii) and (iv) only
All of the above
None of the above
Flagellate isogametes and anisogametes are found in
Spirogyra
Fucus
Volvox
Chlamydomonas
Which of the following branch of science is being described by the given statements ?
(i) It can easily done by using computers based on all observable characters.
(ii) Numbers and codes are assigned to all the characters and the data are then processed.
(iii) Each character is given equal weightage and at the same time hundred of characters can be considered.
Cytotaxonomy
Numerical taxonomy
Chemotaxonomy
??-taxonomy
Which of the following statements with respect to algae are correct.
(i) Fusion between one large, non-motile female gamete and a smaller, motile male gamete is termed as oogamous.
(ii) Fusion of two gametes dissimilar in size is termed as oogamous.
(iii) Fusion of two gametes similar in size is called anisogamous.
(iv) In chlorophyceae, the major pigments are chlorophyll a and b , and the food is stored as starch.
(v) In rhodophyceae, the major pigments are chlorophyll a and d , and the food is stored as mannitol.
(i) and (v)
(iii) and (v)
(i) and (ii)
(i) and (iv)
Cytological information like chromosome number, structure, behaviour are related with
numerical taxonomy
cytotaxonomy
chemotaxonomy
all of the above
You are given an unknown plant to study in the laboratory. You find that it has chlorophyll, no xylem. Its multicellullar sex organs are enclosed in a layer of jacket cells. Its gametophyte stage is free living. The plant probabily belongs to
chlorophyceae
bryophyte
pteridophyte
gymnosperm
Cycas and Adiantum resemble each other in having
seeds
motile sperms
cambium
vessels
Match column-I with column-II and choose the correct option.
| Column-I | Column-II |
|---|---|
| A. Amphibian of the | I. Sphagnum plant kingdom |
| B. Specialized structures | II. Angiosperms in liverworts for asexual reproduction |
| C. Monocotyledons and | III. Bryophytes dicotyledons |
| D. A plant which has | IV. Gemmae capacity to holding water |
A III; B IV; C I; D II
A III; B IV; C II; D I
A IV; B III; C II; D I
A III; B II; C IV; D I
Which one of the following statement concerning the algae is incorrect ?
Most algae are photosynthetic.
Algae can be classified according to their pigments.
All algae are filamentous.
Spirogyra does not produce zoospores.
Which of the following statements about algae is/are correct?
(i) Algae are chlorophyll bearing simple, thalloid, heterotrophic and aquatic (both fresh water and marine) organisms.
(ii) Algae reproduce by vegetative means only.
(iii) Fusion of two gametes dissimilar in size is termed as oogamous.
(iv) A few of the massive forms of algae such as kelps, form massive plant bodies.
Only (i)
Both (i) and (iii)
Only (iv)
All of these
Match the column I with column II and choose the option which shows its correct combination.
| Column-I | Column-II |
|---|---|
| (Pattern of life cycle in plant) | (Examples) |
| A. Haplontic | I. Bryophytes, Pteridophytes, life cycle Ectocarpus, Polysiphonia, Kelps |
| B. Diplontic | II. Seed bearing plants life cycle (Gymnosperm and Angiosperm), Fucus |
| C. Haplo-diplontic | III. Many algae (Volvox, life cycle Spirogyra) and some species of Chlamydomonas |
A III; B II; C I
A I; B II; C III
A II; B I; C III
A III; B I; C II
Match column-I with column-II and select the correct answer using the codes given below.
| Column-I | Column-II |
|---|---|
| (Group of Planet Kingdom) | (Examples) |
| A. Algae | I. Solanum tuberosum |
| B. Fungi | II. Equisetum |
| C. Angiosperm | III. Cycas |
| D. Pteridophyte | IV. Chlamydomonas |
| E. Gymnosperm | V. Rhizopus |
A V; B IV; C I; D II; E III
A IV; B V; C I; D II; E III
A IV; B I; C V; D II; E III
A IV; B I; C V; D III; E II
Consider the following statements regarding gymnosperms and choose the correct option.
(i) In gymnosperms, the male and female gametophytes have an independent existence.
(ii) The multicellular female gametophyte is retained within the megasporangium.
(iii) The gymnosperms are heterosporous. Of these statements
(i) and (ii) are correct but (iii) is incorrect
(i) and (iii) are correct but (ii) is incorrect
(ii) and (iii) are incorrect but (i) is correct
(ii) and (iii) are correct but (i) is incorrect
In angiosperms, a mature male gametophyte is derived from a pollen mother cell by
three mitotic divisions.
one meiotic and two mitotic divisions.
two meiotic divisions.
a single meiotic division.
The spreading of living pteridophytes is limited and restricted to narrow geographical region because
gametophytic growth needs cool, damp and shady places.
it requires water for fertilization.
due to absence of stomata in leaf and absence of vascular tissue.
both (a) and (b)
Which of the following pteridophytes belong to class pteropsida?
Equisetum and Psilotum
Lycopodium and Adiantum
Selaginella and Pteris
Pteris and Adiantum
What is the number and position of insertions of flagella in rhodopyceae class of algae ?
2 - 8, equal, apical
2, unequal, lateral
2 - 6, equal, lateral
Absent
Statement 1: Double fertilization is a characteristic feature of angiosperms.
Statement 2: Double fertilization involves two fusions.
Both statements -1 and statement - 2 are true and statement - 2 is the correct explanation of statement - 1.
Both statements -1 and statement - 2 are true but statement - 2 is not the correct explanation of statement - 1.
Statement -1 is true and statement - 2 is false.
Statement -1 is false and statement - 2 is true.
Match column-I with column-II and choose the correct option.
| Column-I | Column-II |
|---|---|
| A. Phaeophyceae | I. Have an elaborate mechanism of spore dispersal |
| B. Rhodophyceae | II. first terrestrial plant with vascular tissue-phloem and xylem |
| C. Mosses | III. Asexual reproduction by biflagellate zoosposes |
| D. Pteridophytes | IV. Polysiphonia, Porphyra, Gracilaria |
A III; B IV; C I; D II
A IV; B III; C I; D II
A IV; B III; C II; D I
A IV; B I; C III; D II
In class phaeophyceae, the plant body is usually attached to the substratum by a A and has a stalk, the B and leaf like photosynthetic organ-the C .
A holdfast, B stipe, C frond
A stipe, B holdfast, C frond
A frond, B stipe, C holdfast
A stipe, B frond, C holdfast
Which one of the following is the major difference between mosses and ferns ?
Ferns lack alternation of generation while mosses show the same.
Mosses are facultative aerobes while ferns are obligate aerobes.
Vascular bundles of ferns show xylem vessels while those of mosses lack it.
Sporophytes of ferns live much longer as compared to the sporophytes of mosses.
Which of the following statement(s) is/are correct about pteridophytes ?
(i) The main plant body is a sporophyte which is differentiated into true roots and leaves.
(ii) The leaves are small (microphylls) as in ferns or large (macrophylls) as in Selaginella.
(iii) Genera like Selaginella and Salvinia which produce two kinds of sporesmacro (large) and micro (small) spores, are known as heterospores.
(iv) Common examples are Funaria, Polytrichum and Sphagnum.
Both (i) and (ii)
Both (ii) and (iii)
Both (i) and (iii)
All of these
Match the classes of pteridophytes given in column I with their examples given in column II and choose the correct option
| Column -I | Column-II |
|---|---|
| (Classes of pteridophytes) | (Examples) |
| A. Psilopsida | I. Selaginella |
| B. Lycopsida | II. Psilotum |
| C. Sphenopsida | III. Dryopteris |
| D. Pteropsida | IV. Equisetum |
A II; B I; C IV; D III
A I; B II; C IV; D III
A II; B I; C III; D IV
A II; B IV; C I; D III
The following statements are associated with one class of algae. Identify the class of algae.
(i) One or more storage bodies called pyrenoids located in the chloroplasts are present in the members of this class.
(ii) They have a rigid cell wall made of an inner layer of cellulose and an outer layer of pectose.
(iii) Asexual reproduction is by flagellated zoospores produced in zoosporangia.
(iv) Chlamydomonas, Volvox, Ulothrix, Spirogyra and Chara are commonly found members of this class.
Chlorophyceae
Rhodophyceae
Phaeophyceae
None of these
Which of the following statement is incorrect ?
Double fertilization is unique to gymnosperms and monocotyledons.
Sequoia, a gymnosperm, is one of the tallest tree species.
Phaeophyceae members possess chlorophyll a, c, carotenoids and xanthophylls.
Moss is a gametophyte which consists of two stages namely, protonemal stage and leafy stage.
The unique feature of bryophytes compared to other plant groups is that
they produce spores.
they lack vascular tissues.
they lack roots.
their sporophyte is attached to the gametophyte.