Cell the Unit of Life MCQs

Consider the following statements regarding the discovery and history of cell biology:

I. Antonie Von Leeuwenhoek first saw and described a live cell.
II. Robert Brown discovered the nucleus inside the cell.
III. Matthias Schleiden, a German zoologist, concluded that all plant tissues are composed of cells.
IV. Rudolf Virchow modified the cell theory by introducing the concept of Omnis cellula-e cellula.

Which of the above statements are correct?

Consider the following statements about cell theory:

I. Schleiden and Schwann together formulated the original cell theory.
II. Theodore Schwann proposed that the presence of a cell wall is a unique character of plant cells.
III. The original cell theory of Schleiden and Schwann explained clearly how new cells are formed.
IV. According to modern cell theory, all living organisms are composed of cells and products of cells.

Which of the statement combinations is correct?

Which of the following statements regarding cellular dimensions and shapes are correct?

I. Mycoplasmas are the smallest cells with a length of only 0.3 μm.
II. Human red blood cells are about 7.0 μm in diameter and are disc-like and biconcave.
III. Typical bacteria range in size from 3 to 5 μm.
IV. The largest isolated single cell is the egg of an ostrich.

Consider the following statements regarding prokaryotic structural organization:

I. All prokaryotes have a cell wall surrounding the plasma membrane without any exception.
II. Prokaryotes lack a well-defined nucleus, and their genetic material is naked.
III. In addition to genomic DNA, many bacteria possess small circular extra-chromosomal DNA called plasmids.
IV. Plasmids confer unique phenotypic characters like antibiotic resistance to bacteria.

Which of the statements are correct?

Consider the statements regarding the bacterial cell envelope:

I. The cell envelope consists of a tightly bound three-layered structure: glycocalyx, cell wall, and plasma membrane.
II. Each layer of the cell envelope performs a distinct function, but together they act as a single protective unit.
III. A loose sheath of glycocalyx is termed a capsule, whereas a thick and tough layer is called a slime layer.
IV. Bacteria are classified into Gram-positive and Gram-negative based on differences in their cell envelopes and response to Gram stain.

Which options highlight the correct statements?

Which of the following statements about mesosomes in prokaryotes are correct?

I. Mesosomes are formed by the extensions of the plasma membrane into the cell.
II. Mesosomal extensions can be in the form of vesicles, tubules, and lamellae.
III. Mesosomes help in cell wall formation, DNA replication, and equal distribution to daughter cells.
IV. Mesosomes increase the surface area of the plasma membrane and its enzymatic content.

Which of the above statements are correct?

Consider the following statements regarding bacterial motile and surface structures:

I. Bacterial flagella arise from the cell wall and consist of three parts: filament, hook, and basal body.
II. The filament is the longest portion of the flagellum and extends from the cell surface to the outside.
III. Pili and fimbriae play a major role in bacterial motility.
IV. Fimbriae are small bristle-like fibers that help attach bacteria to rocks in streams and host tissues.

Which statements are correct?

Read the following statements about prokaryotic ribosomes and inclusion bodies:

I. Prokaryotic ribosomes are 70S type, composed of 50S and 30S subunits.
II. Several ribosomes may attach to a single mRNA to form a chain called a polysome or polyribosome.
III. Inclusion bodies in prokaryotes are bound by a single membrane unit and stored in cytoplasm.
IV. Gas vacuoles are found in blue-green, purple, and green photosynthetic bacteria.

Which of the combinations is correct?

Which of the following statements regarding plant and animal cell differences are correct?

I. Plant cells possess cell walls, plastids, and a large central vacuole, which are absent in animal cells.
II. Animal cells possess centrioles, which are absent in almost all plant cells.
III. Animal cells have a large central vacuole occupying 90% of the cell volume.
IV. Both plant and animal cells possess membrane-bound nuclei and organelles.

Which of the above statements are correct?

Select the correct statements regarding the fluid mosaic model of plasma membrane:

I. Proposed by Singer and Nicolson in 1972.
II. Phospholipids are arranged in a bilayer with polar heads facing inwards and hydrophobic tails facing outwards.
III. The quasi-fluid nature of lipids enables lateral movement of proteins within the overall bilayer.
IV. Human erythrocyte membrane has approximately 52% protein and 40% lipids.

Which statements are correct?