Question

Cells which lack nuclear membrane are?

Answer 1

The outer covering of the nucleus is known as a nuclear membrane. It is also known as the nuclear envelope. The nuclear membrane functions as a barrier between the nucleus and cytoplasm.

Complete answer:
The cells that lack a nuclear membrane are known as prokaryotic cells. These are one of the earliest cells to have existed on the Earth. The organisms consisting of prokaryotic cells are known as prokaryotes and are unicellular. These cells are very primitive in nature and do not contain specialized membrane bound organelles such as mitochondria, Golgi bodies, and lysosomes. These cells have an outer covering called the cell wall and is made up of amino acids and carbohydrates.

The nucleus in these cells is primitive and is known as a nucleoid which carries the genetic material. The only organelle present in these cells are Ribosomes which are scattered in the cytoplasm and are involved in the synthesis of proteins. A distinctive characteristic of these types of cells is the presence of Plasmids, which are extra chromosomal circular DNA.

Some of the cells have hair-like structures on it known as flagella that help in the movement of the organism. Examples of prokaryotic organisms are Archaebacteria and Cyanobacteria or Blue- green Algae.

Note: The cells consisting of a well-defined and well-developed nucleus are known as Eukaryotic cells. These cells contain nuclei with a nuclear membrane as well as membrane-bound organelles such as mitochondria, Golgi bodies, lysosomes, and chloroplasts. All multicellular organisms are made of eukaryotic cells. Examples of eukaryotic organisms are organisms belonging to the Kingdom Protista, Animalia, and Plantae.