Question

Nuclear membrane is absent in:
A) Plantae
B) Protista
C) Monera/Nostoc
D) Fungi

Answer 1

They are the simple unicellular, prokaryotic organisms. The bacterial cell is not made up of cellulose. The cell organelles and well-defined nucleus are absent in these organisms. Examples are: cyanobacteria, mycoplasma.

Complete Answer:
- The nucleus is surrounded by the two lipoprotein membranes which is called a nuclear membrane. It is a double membrane that encloses the nucleus. Nuclear membrane is absent in kingdom Monera because it lacks well-defined nucleus and other membrane bound cell organelles like mitochondria, Golgi apparatus and chloroplast. Monera are the unicellular, prokaryotic organisms whose cell wall is not made up of cellulose. Cyanobacteria, mycoplasma are examples of Monera.

- Kingdom plantae are the multicellular, eukaryotic organisms that have well defined nucleus and nuclear membrane is present. They store food in the form of starch and oil. Their cell wall is made up of cellulose. They manufacture their own food with the help of photosynthesis.

- Protists are the unicellular, eukaryotic organisms. They do not lack well-defined nucleus and membrane bound cell organelles are present. Examples: paramecium, amoeba, algae.

- Fungi are the multicellular, eukaryotic and non-green organisms whose cell wall is made up of chitin. They are non-photosynthetic and store food as glycogen. They reproduce by spore formation. Examples: yeast, penicillium.

Thus, the correct answer is option C. i.e., Monera/Nostoc.

Note: R.H. Whittaker in 1969 introduced 5 kingdom classification. These are: Monera, Protista, Fungi, Plantae and Animalia. Except Monera all other kingdoms are eukaryotic organisms. Monera and Protista are the unicellular organisms and rest are the multicellular organisms. Except Monera, nuclear membrane is present in all 4 kingdoms.