I. Mitochondria and chloroplasts are double membrane-bound. II. Lysosomes, vacuoles, and microbodies are single membrane-bound. III. Ribosomes and centrosomes are non-membrane-bound. IV. Endoplasmic reticulum and Golgi apparatus are non-membrane-bound organelles.
Which options are correct?
Mitochondria and chloroplasts possess double membranes, lysosomes, vacuoles, and microbodies are single membrane-bound, and ribosomes and centrosomes are non-membrane-bound. Statement IV is incorrect because the endoplasmic reticulum and Golgi apparatus are membrane-bound organelles.
Question 92 of 100
ð CLASS XI
Which statements about cell size comparisons are correct?
I. Mycoplasma (0.3 Ξm) is smaller than typical bacteria (3â5 Ξm). II. PPLO (about 0.1 Ξm) is smaller than typical bacteria (1â2 Ξm). III. Human RBC (7.0 Ξm) is smaller than a typical eukaryotic cell (10â20 Ξm). IV. Virus (0.02â0.2 Ξm) is larger than a typical eukaryotic cell.
Which statements are correct?
Mycoplasma and PPLO are much smaller than typical bacteria, and human RBCs are smaller than typical eukaryotic cells. Statement IV is incorrect because viruses are much smaller than eukaryotic cells.
Question 93 of 100
ð CLASS XI
Select the correct statements regarding Gram staining:
I. Gram staining was developed by Christian Gram. II. Bacteria taking up the Gram stain are called Gram-positive. III. Bacteria not taking up the Gram stain are called Gram-negative. IV. Gram staining is based on differences in the bacterial cell envelope structure.
Which statements are correct?
Gram staining was developed by Christian Gram. Gram-positive bacteria retain the stain, whereas Gram-negative bacteria do not. The classification is based on differences in the bacterial cell envelope structure.
Question 94 of 100
ð CLASS XI
Read statements regarding Glycocalyx variations:
I. Loose sheath is slime layer. II. Thick and tough layer is capsule. III. Differs in composition and thickness among bacteria. IV. Forms middle cell wall layer.
Which statements are correct?
The glycocalyx is the outermost layer of the bacterial cell envelope and occurs as a loose slime layer or a thick capsule. It varies in composition and thickness among bacteria. Statement IV is incorrect because the cell wall forms the middle layer.
I. Formed by plasma membrane infoldings. II. Present in the form of vesicles, tubules, and lamellae. III. Help in secretion and respiration. IV. Present only in eukaryotic plant cells.
Which statement combination is correct?
Mesosomes are infoldings of the plasma membrane found in prokaryotes. They occur as vesicles, tubules, and lamellae and function in respiration, secretion, DNA replication, and cell wall formation. Statement IV is incorrect because mesosomes are absent in eukaryotic plant cells.
Question 96 of 100
ð CLASS XI
Which statements about polysome (polyribosome) are correct?
I. It is a chain of ribosomes attached to a single mRNA. II. It translates mRNA into proteins. III. It is found in prokaryotic cytoplasm. IV. It is bound by the outer nuclear membrane only.
Which statements are correct?
Several ribosomes attached to a single mRNA form a polysome or polyribosome and simultaneously synthesize proteins. Statement IV is incorrect because polysomes are not membrane-bound.
Question 97 of 100
ð CLASS XI
Read statements regarding gas vacuoles:
I. Found in blue-green bacteria. II. Found in purple photosynthetic bacteria. III. Found in green photosynthetic bacteria. IV. Membrane-bound organelle containing DNA.
Which option is correct?
Gas vacuoles occur in blue-green, purple, and green photosynthetic bacteria and help in buoyancy. Statement IV is incorrect because gas vacuoles are non-membrane-bound inclusion bodies and do not contain DNA.
Question 98 of 100
ð CLASS XI
Consider statements regarding cell wall of algae vs higher plants:
I. Algal cell wall contains galactans and mannans. II. Algal cell wall contains calcium carbonate. III. Higher plant cell wall contains pectins and hemicellulose. IV. Both contain peptidoglycan as the major component.
Which statements are correct?
The algal cell wall contains cellulose along with galactans, mannans, and calcium carbonate in some algae. Higher plant cell walls contain cellulose, hemicellulose, pectins, and proteins. Statement IV is incorrect because peptidoglycan is characteristic of bacterial cell walls.
Question 99 of 100
ð CLASS XI
Select the correct statements regarding Svedberg's unit (S):
I. It stands for sedimentation coefficient. II. It is an indirect measure of density and size. III. It applies to both 70S and 80S ribosomes. IV. It is a direct measure of ribosomal molecular weight in Daltons.
Which statements are correct?
Svedberg's unit (S) represents the sedimentation coefficient and is an indirect measure of the size and density of particles such as 70S and 80S ribosomes. Statement IV is incorrect because it is not a direct measure of molecular weight.
Question 100 of 100
ð CLASS XI
Read the final set of statements regarding nuclear pores and perinuclear space:
I. Perinuclear space is 10 to 50 nm wide. II. Nuclear pores allow bidirectional transport of RNA and proteins. III. Nuclear envelope separates nucleoplasm from cytoplasm. IV. Nuclear pores are covered by a thick chitinous cell wall.
Which statements are correct?
The perinuclear space measures 10 to 50 nm. Nuclear pores permit bidirectional transport of RNA and proteins, and the nuclear envelope separates the nucleoplasm from the cytoplasm. Statement IV is incorrect because nuclear pores are not covered by a chitinous cell wall.
