Question

in class prof mentioned

there is diplococcus & streptococci

but there's NO tetrad coccus or tetrad bacilli, we just call it tetrad bacteria or tetrad arrangement.

so my question is what about sarcinae? do we call it Sarcinae-coccus or just Sarcinae bacteria or Sarcina bacteria or Sarcinae arrangement?

so if there is Diplococcus & Streptococci & Staphylococci ... why only NO tetradcocci? or sarcinaecocci??

also plural and singular matters??

answer my question or no credit will be given.

thanks

Answer 1

• Coccus -single bacterial cell which is round ,oval or spherical in shape.
• Cocci- plural form and made up of two or more cells.

Depending on the number and arrangement of cells,round or spherical cells can be defined as

• Coccus -Single bacterial cell.
• Diplococci - Group of 2 cells
• Staphylococci-Cluster of cocci or cells arranged in grapes like shape
• Streptococci-Bacterial cells arranged in chains
• Sarcina-Group of 8 cells(* Sarcina arrangement)
• Tetrad-Group of 4 bacterial cells

Rod shaped cells are called Bacillus.

• Bacillus- Single bacterial cell-Singular
• Bacilli- more than one cell -Plural form

Rod shapped cells are arranged as

• Diplobacilli-Group of 2 cells
• Streptobacilli - Bacilli in chains.