Question 9
Differentiate between the following:-
(i)red algae and brown algae
(ii) liverworts and moss
(iii) homosporous and heterosporous pteridophyte
(iv) syngamy and triple fusion
(i) Red algae and brown algae
Red algae | Brown algae | ||
1. | Red algae are grouped under the class Rhodophyceae. | 1. | Brown algae are grouped under the class Phaeophyceae. |
2. | They contain floridean starch as stored food. | 2. | They contain mannitol or laminarin as stored food. |
3. | They contain the photosynthetic pigments chlorophylls a and d, and phycoerythrin. | 3. | They contain the photosynthetic pigments chlorophylls a and c, and fucoxanthin. |
4. | Their cell walls are composed of cellulose, pectin, and phycocolloids. | 4. | Their cell walls are composed of cellulose and algin. |
5. | Flagella are absent | 5. | Two flagella are present |
(ii) Liverworts and moss
Liverworts | Moss | ||
1. | They have unicellular rhizoids. | 1. | They have multicellular rhizoids. |
2. | Scales are present very often | 2. | Scales are absent |
3. | They are generally thalloid, with dichotomous branching. | 3. | They are foliage, with lateral branching. |
4. | Gemma cups are present | 4. | Gemma cups are absent |
5. | Sporophyte has very little photosynthetic tissue | 5. | Sporophyte has abundant photosynthetic tissue |
(iii) Homosporous and heterosporous pteridophyte
Homosporous pteridophytes | Heterosporous pteridophytes | ||
1. | They bear spores that are of the same type. | 1. | They bear two kinds of spores – microspores and megaspores. |
2. | They produce bisexual gametophytes. | 2. | They produce unisexual gametophytes. |
(iv) Syngamy and triple fusion
Syngamy | Triple fusion | ||
1. | It is the process of fusion of the male gamete with the egg in an angiosperm. | 1. | It is the process of fusion of the male gamete with the diploid secondary nucleus in an angiosperm. |
2. | A diploid zygote is formed as a result of syngamy. | 2. | A triploid primary endosperm is formed as a result of triple fusion. |
