Biology Written Test Questions and Answers for Class 11 on “Plant Kingdom – Algae-2”.
1. Which of the following modes are used by spirogyra to reproduce?
a) Fragmentation
b) Multiple fission
c) Spore formation
d) Binary fission
Answer: a
Clarification: In fragmentation, a parent organism breaks into a fragment and each fragment gives a new individual. Spirogyra uses fragmentation to reproduction.
2. During unfavourable conditions, the outer layer that is formed in chlamydomonas is called as ______
a) Cyst
b) Nuclear membrane
c) Cell wall
d) Cellular membrane
Answer: a
Clarification: During unfavourable conditions, an outer layer that is formed outside chlamydomonas is called cyst. These unfavourable conditions allow multiple fission inside the cyst.
3. Which among the following is an incorrect statement?
a) Multiple fission is a process through which many individuals are produced by repeated nuclear division
b) Multiple fission takes place under suitable conditions
c) During multiple fission, an outer layer called cyst is formed
d) Nucleus divides repeatedly and new individuals are formed inside the cyst after which cyst breaks to release new individuals
Answer: b
Clarification: Multiple fission is a process through which many individuals are produced by repeated nuclear division. Multiple fission takes place under unfavourable conditions. During multiple fission, an outer layer called cyst is formed. Nucleus divides repeatedly and new individuals are formed inside the cyst after which cyst breaks to release new individuals.
4. Which among the following is an incorrect statement?
a) Most of the algae reproduce using spore formation
b) Asexual spores are called as zoo-spores and the reproductive part in algae is called zoosporangium
c) Under favourable conditions, these organisms germinate to form new organism
d) Zoo-spores are non-motile and flagellated
Answer: d
Clarification: Most of the algae reproduce using spore formation. Asexual spores are called as zoo-spores and the reproductive part in algae is called zoosporangium. Under favourable conditions, these organisms germinate to form new organism. Zoo-spores are motile and flagellated.
5. Reproduction in humans is an example of _______
a) Isogamous
b) Anisogamous
c) Oogamous
d) Sapiogamous
Answer: c
Clarification: In oogamous mode of reproduction, the larger gamete is non-motile and smaller gamete is motile. In humans, sperms being the smaller gamete are motile and the egg being the larger gamete is non-motile. Therefore, reproduction in humans is an example of oogamous reproduction.
6. The male gamete in sexual reproduction of algae is called as _______
a) Antherozoid
b) Egg
c) Basidiogamete
d) Zoosperm
Answer: b
Clarification: The male gamete in sexual reproduction of algae is called antherozoid and the female gamete is called egg. These two gametes fuse to form a zygote which will further develop to form spores.
7. Gelidium and Gracilaria is used in the formation of _______
a) Agar
b) Vinegar
c) Yoghurt
d) Beer
Answer: a
Clarification: Gelidium and Gracilaria is used in the formation of Agar. Agar is used in the preparation of ice-creams and jellies. Apart from the preparation of ice-creams, agar has different uses in both industries and in research.
8. Which among the following is incorrect?
a) Algae help in increasing oxygen levels in the environment
b) Chlorella and Spirullina are multi-cellular algae that are rich proteins and are used as food supplements for space travelers
c) Chlorophyceae comprise algae that contain chlorophyll a and chlorophyll b
d) Chlorophyceae store food as proteins, starch or as oil droplets