Courses
Courses for Kids
Free study material
Offline Centres
More
Store Icon
Store
seo-qna
SearchIcon
banner

Shape of cocci bacteria is
A. Rod-shaped
B. Comma-shaped
C. Spiral
D. Spherical

Answer
VerifiedVerified
484.2k+ views
Hint: Bacterial cells are connected outside of their sturdy walls, giving bacteria their characteristic shape. Almost all forms of cocci are whip less and immobile. Staphylococcus aureus and Streptococcus pneumoniae bacteria have such a type of shape. These bacteria may remain singly or attached with each other.

Complete answer:
Let’s first understand about all the shapes of bacteria.
Rod-shaped: Rod-like bacteria are called bacillus. Most bacterial cells look like a line (-) or a small rod under a microscope. The stems can be cylindrical and straight or slightly curved or wavy with rounded or blunt ends. This is bacilli (sing, bacilli). Bacillus is a Latin word and means "stick or little stick". The bacillary form is the most common. B. subtilis, B. anthracis, and Lactobacillus are common examples of rod-shaped bacteria. In some bacilli, the stems are so short they cannot be distinguished from the spherical shape.
Spiral : Bacteria whose body is twisted one to five full turns like a corkscrew is a spiral. This spiral is longer than cocci and bacilli There were fewer of them, perhaps less than hundred species. The spiral shape usually has two or more flagella at one or both poles. They occur as single cells or in short chains, but do not form colonies. Urdulum spirillum and S. volutans are common examples of this type.
Comma-shaped: Comma shaped bacteria are known as Vibrio .Bacterial cells in Vibrios are short and resemble curved rods or spiral ropes. In fact, it is smaller than a full spiral and has a slightly bent comma shape. Vibrio has flagella on only one pole .
Spherical: Spherical shapes are known as Coccyx (pleural cocci). They can occur in pairs (diplococci), four groups (tetracocci), groups (staphylococci), chains (streptococci), or more than eight cubic structures (Sarcinae). For example – Staphylococcus aureus.
Hence, the correct option is spherical shape bacteria (D).

Note:
Cocci denote various types of cell arrangements. In some cocci, most of the single cells remain. In this case, they are called micrococci. When cocci usually come in pairs, they are called diplococci. If the daughter cells stay in a chain, they are called streptococci. When cocci divide into two levels, they produce irregular groups of cells known as staphylococci. When cells are divided into three planes at right angles to each other, a cubic arrangement is obtained, and then they are called sarcinae.
Mycoplasma does not have a cell wall and also does not have a characteristic shape. The fact that the cell wall is responsible for the formation of bacterial cells can also be seen when the wall is removed by enzymes.