Question

A photosynthetic organism which does not release oxygen is:

• A. Blue-green alga
• B. Green sulphur bacterium
• C. Green alga
• D. Algal component of lichen.

Answer 1

The correct option is B

Green sulphur bacterium

The correct option is B.

Explanation for correct option:

1. Archaebacteria are said to be obligate or facultative anaerobes meaning they flourish in absence of oxygen and can undergo methanogenesis.
2. The cell membranes of these Archaebacteria are made up of lipids. The rigid cell wall is also responsible for providing shape and support to the Archaebacteria & normally prevents from bursting under hypotonic conditions.
3. They do not possess membrane-bound organelles like the nuclei, endoplasmic reticulum, mitochondria, lysosomes or chloroplast. These can also withstand very high temperature and pressure conditions.

Explanation for incorrect options:

Option A:

1. Blue-Green Algae are the type of photosynthetic bacteria which consist either of single cells or the colonies which is also known as Cyanobacteria.
2. Cyanobacteria generally contain only 1 type of chlorophyll, Chlorophyll a, green pigment.
3. In addition to this, they also contain pigments like carotenoids, phycobilin.

Option C:

1. Chlorophyceae: Chlorophyll a and b are present imparting a green color. Chlorophyceae are also referred as ‘green algae’.
2. The fungal part is called as mycobiont and the non-fungal part is called as photobiont which contains chlorophyll.
3. Many lichen partners also include one photobiont & one mycobiont that is not universal & there are lichens with more than one photobiont partner.

Option D:

1. The fungal part is called as mycobiont and the non-fungal part is called as photobiont which contains chlorophyll.
2. Many lichen partners also include one photobiont & one mycobiont that is not universal & there are lichens with more than one photobiont partner.

Final answer: A photosynthetic organism which does not release oxygen is green sulphur bacterium.