Which of the following is a defining feature of prokaryotic cells? MCQ with Answer and Explanation

Which of the following is a defining feature of prokaryotic cells?
A. Presence of 70S ribosomes only
B. Absence of cell wall
C. Linear chromosomes
D. Presence of membrane-bound nucleus
Answer: Option A
Solution (By JKSSB Mock Tests)
Prokaryotic cells lack a true nucleus; their genetic material is located in a nucleoid region. They possess 70S ribosomes (50S+30S subunits), whereas eukaryotic cells have 80S ribosomes. Prokaryotes generally have a cell wall (except Mycoplasma) and circular DNA, not linear. Membrane-bound organelles like mitochondria, ER are absent. Examples: bacteria and blue-green algae. This distinction is fundamental in cell biology.

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Biology Questions

Question #1
The process of separating proteins based on their net charge is:
A. Gel filtration chromatography
B. Affinity chromatography
C. SDS-PAGE
D. Ion exchange chromatography

Correct Answer: Option D


Explanation:
Ion exchange chromatography separates proteins based on their net surface charge; positively charged proteins bind to cation exchangers, negatively to anion exchangers. Gel filtration separates by size, affinity by specific binding, SDS-PAGE by molecular weight.

This question belongs to: Science Biology
Question #2
The type of epithelial tissue that lines the urinary bladder and allows stretching is:
A. Transitional epithelium
B. Stratified squamous
C. Simple squamous
D. Columnar epithelium

Correct Answer: Option A


Explanation:
Transitional epithelium (urothelium) is stratified, with cells that can change shape from cuboidal to squamous when the bladder distends. It lines the renal pelvis, ureters, bladder, and part of the urethra. Squamous is flat, cuboidal cube-shaped, columnar tall.

This question belongs to: Science Biology
Question #3
In animal husbandry, the 'Leghorn' is a high-yielding breed of:
A. Layer chicken (egg production)
B. Beef cattle
C. Dairy cattle
D. Broiler chicken (meat production)

Correct Answer: Option A


Explanation:
The Leghorn (specifically the White Leghorn) is a highly popular and productive breed of chicken originating from Tuscany, Italy. It is primarily reared as a layer breed for commercial egg production due to its high egg yield, early maturity, and efficient feed conversion. It is not typically used for meat production (broilers like Cornish Cross are preferred for that) or as cattle. Rhode Island Red is another dual-purpose breed, but Leghorn is specifically famous for eggs.

This question belongs to: Science Biology