Cyanophyta

Question 1

What are the defining characteristics of cyanophytes that classify them as prokaryotic cells? s

Answer 1

Cyanophytes are prokaryotic, meaning they lack a true nucleus and membrane-bound organelles. Their genetic material is not enclosed within a nuclear membrane

Question 2

List and explain the primary pigments found in cyanophytes and their roles. s

Answer 2

Cyanophytes contain chlorophyll a, phycocyanin (blue pigment), and phycoerithrin (red pigment). These pigments are crucial for capturing light energy for photosynthesis

Question 3

How do cyanophytes move, given that they lack flagella?

Answer 3

Cyanophytes move through rhizopodial movement and by secreting mucilage, which reduces friction and allows them to glide

Question 4

Define cyanophycin and explain its importance as a food reserve.

Answer 4

Cyanophycin is a nitrogenous food reserve composed of amino acids like arginine and aspartic acid. It serves as a storage compound for nitrogen and carbon, aiding in survival during nutrient scarcity

Question 5

What is the significance of heterocysts in cyanophytes?

Answer 5

Heterocysts are specialized cells that provide an anaerobic environment necessary for nitrogen fixation, converting atmospheric nitrogen into ammonia

Question 6

Describe the structure and function of akinetes

Answer 6

Akinetes are thick-walled, dormant cells that allow cyanophytes to survive unfavorable conditions. They germinate into new filaments when conditions improve

Akinetes form in response to harsh conditions like drought or cold. They remain dormant until favorable conditions return, ensuring survival and regrowth

Question 7

How do gelatinous sheaths contribute to colony formation?

Answer 7

Gelatinous sheaths hold cells together in colonies, providing structural support and protection from environmental stressors like desiccation and UV radiation

Question 8

Explain the movement mechanism in Oscillatoria

Answer 8

Oscillatoria moves by rotating and gliding, facilitated by the secretion of mucilage, which reduces friction

Question 9

Compare and contrast the different methods of reproduction in cyanophytes

Answer 9

Cyanophytes reproduce asexually through binary fission, fragmentation, and spore formation. They do not undergo sexual reproduction.

Question 10

How does the presence of phycobilins affect photosynthetic efficiency in different light conditions?

Answer 10

Phycobilins, such as phycocyanin and phycoerithrin, absorb light energy for photosynthesis and contribute to the blue-green coloration of cyanophytes

Phycobilins enhance photosynthetic efficiency by capturing a broad spectrum of light, especially in low-light aquatic environments.

Question 11

Explain the process of fragmentation in filamentous forms and its ecological advantages.

Answer 11

Fragmentation involves breaking filaments into smaller pieces, each capable of growing into a new organism. This allows rapid colonization and adaptation

Question 12

How do cyanophytes maintain buoyancy in aquatic environments?

Answer 12

Cyanophytes maintain buoyancy through gas vesicles and gelatinous sheaths, allowing them to access optimal light conditions for photosynthesis.

Question 13

Analyze the role of hormogonia in cyanophyte reproduction and dispersal

Answer 13

Hormogonia are motile filaments that aid in dispersal and colonization, allowing cyanophytes to exploit new habitats

Question 14

How do cyanophytes contribute to soil fertility in paddy fields?

Answer 14

Cyanophytes fix nitrogen in paddy fields, enhancing soil fertility and supporting rice growth.

Question 15

Evaluate the positive and negative impacts of cyanophytes on human activities.

Answer 15

Positively, cyanophytes are used as dietary supplements and biofertilizers. Negatively, they can cause harmful algal blooms, producing toxins that affect water quality and health.

Question 16

Discuss the implications of cyanotoxins in water management systems

Answer 16

Cyanotoxins pose risks to water quality and health. Solutions include monitoring programs, nutrient management, and advanced water treatment technologies.

Question 17

Discuss the relationship between colony formation and survival advantages in cyanophytes

Answer 17

Colonies provide structural integrity, protection, and enhanced nutrient acquisition, increasing survival rates in various environments

Question 18

Discuss the ecological significance of cyanophytes in aquatic environments and their role in the nitrogen cycle. Include examples of how they contribute to both the ecosystem and human activities

Question 19

Essay Question : Analyze the positive and negative impacts of blue-green algae on human health and the environment. Provide examples of both beneficial uses and harmful effects.

Question 20

Explain the process of nitrogen fixation in cyanophytes, including the role of heterocysts. How does this process benefit agricultural practices?

Question 21

6. Which pigments are primarily responsible for the coloration of cyanophytes?
   
   • A) Chlorophyll b and carotenoids
   • B) Phycocyanin and phycoerithrin
   • C) Xanthophylls and chlorophyll a
   • D) Anthocyanins and chlorophyll b

Question 22

7. What type of cell division is common in blue-green algae?
   
   • A) Meiosis
   • B) Binary fission
   • C) Budding
   • D) Fragmentation

Question 23

8. Which specialized cells in cyanophytes are responsible for nitrogen fixation?
   
   • A) Akinetes
   • B) Heterocysts
   • C) Hormogonia
   • D) Rhizopodia

Question 24

9. How do cyanophytes contribute to oxygen production in aquatic ecosystems?
   
   • A) Through photosynthesis and nitrogen fixation
   • B) By decomposing organic matter
   • C) By forming symbiotic relationships with fish
   • D) Through the release of cyanotoxins

Question 25

10. What is a recent application of cyanophytes in biotechnology?
    
    • A) Development of new antibiotics
    • B) Production of biofuels
    • C) Creation of synthetic fibers
    • D) Enhancement of solar panels

Question 26

True/False : Cyanophytes can reproduce sexually.

Question 27

True/False : Cyanophytes are the only organisms capable of both nitrogen fixation and oxygen production.

Question 28

Describe the role of gelatinous sheaths in the structure of cyanophyte colonies.

Question 29

Explain the significance of hormogonia in the reproduction of cyanophyceae.

Question 30

Identify one environmental challenge posed by cyanotoxins and a potential solution to mitigate its impact.

Question 31

What is cyanophycin, and what role does it play in cyanophytes?

Question 32

The filamentous structure of Oscillatoria allows it to move by _______ and _______ while secreting mucilage.

Question 33

Akinetes are thick-walled resistant cells that can survive _______ conditions and germinate into new filaments when conditions become _______.

Question 34

19. Match the following cyanophyte features with their functions:
    
    • A) Heterocysts
    • B) Phycobilins
    • C) Akinetes
    • D) Hormogonia
      1. Nitrogen fixation
      2. Pigmentation
      3. Dormancy and survival
      4. Reproduction

Question 35

Match the cyanophyte genera with their characteristics:
- A) Nostoc
- B) Anabaena
- C) Oscillatoria
- D) Microcystis
1. Filamentous with heterocysts
2. Known for hormogonia
3. Rotates and glides
4. Forms colonies through fragmentation

Question 36

Evaluate the survival mechanisms of cyanophytes in extreme environmental conditions. Discuss the role of akinetes and other adaptations that enable their persistence.

Question 37

Assess the current research trends in the use of cyanophytes as a sustainable resource for biofuels and bioproducts. What challenges and opportunities exist in this field?