I. Contains enzymes for carbohydrate and protein synthesis. II. Contains small double-stranded circular DNA. III. Contains 70S ribosomes. IV. Lacks any genetic material.
Which option is correct?
The chloroplast stroma contains enzymes required for carbohydrate and protein synthesis, small double-stranded circular DNA, and 70S ribosomes. Statement IV is incorrect because chloroplasts possess their own genetic material.
Question 82 of 100
📘 CLASS XI
Consider statements regarding axoneme of cilia and flagella:
I. Core of cilium or flagellum is called axoneme. II. Axoneme runs parallel to the long axis. III. It has 9 doublets of peripheral microtubules and 2 central single microtubules. IV. It is surrounded by a cell wall.
Which statements are correct?
The core of cilia and flagella is called the axoneme, which runs parallel to the long axis and exhibits the characteristic 9+2 arrangement of microtubules. Statement IV is incorrect because cilia and flagella are enclosed by the plasma membrane, not a cell wall.
Question 83 of 100
📘 CLASS XI
Select the correct statements regarding radial spokes in cilia and flagella:
I. Radial spokes connect the central sheath to one tubule of each peripheral doublet. II. There are a total of 9 radial spokes. III. Peripheral doublets are interconnected by linkers. IV. Radial spokes connect the central tubules directly to the cell wall.
Which statements are correct?
Each of the nine peripheral doublets is connected to the central sheath by a radial spoke, and adjacent peripheral doublets are interconnected by linkers. Statement IV is incorrect because radial spokes do not connect to the cell wall.
Question 84 of 100
📘 CLASS XI
Read statements regarding pericentriolar material and centriole arrangement:
I. Centrioles are surrounded by amorphous pericentriolar material. II. Two centrioles in a centrosome lie perpendicular to each other. III. Centrioles show a cartwheel organization. IV. Centrioles are bound by a double membrane.
Which statements are correct?
Centrioles are embedded in amorphous pericentriolar material, occur in perpendicular pairs, and possess a cartwheel organization. Statement IV is incorrect because centrioles are non-membrane-bound structures.
I. Highly extended nucleoprotein fibers called chromatin are present. II. Nuclear matrix (nucleoplasm) is present. III. One or more spherical bodies called nucleoli are present. IV. Highly condensed metaphase chromosomes with kinetochores are present.
Which statements are correct?
The interphase nucleus contains chromatin, nucleoplasm, and one or more nucleoli. Statement IV is incorrect because highly condensed metaphase chromosomes are seen only during cell division.
Question 86 of 100
📘 CLASS XI
Which statements about chromatin proteins are correct?
I. Histones are basic proteins. II. Non-histone proteins are present in chromatin. III. DNA wraps around histones. IV. Chromatin contains DNA and RNA.
Which statements are correct?
Chromatin consists of DNA associated with basic histone proteins, non-histone proteins, and RNA. DNA is wrapped around histone proteins to form nucleoprotein complexes.
Question 87 of 100
📘 CLASS XI
Read statements regarding centromere function:
I. Primary constriction of chromosome. II. Holds two chromatids of a chromosome. III. Kinetochores are disc-shaped structures on its sides. IV. Site of ribosome assembly.
Which statements are correct?
The centromere is the primary constriction of a chromosome, holds the two sister chromatids together, and bears disc-shaped kinetochores on its sides. Statement IV is incorrect because ribosome assembly occurs in the nucleolus.
Question 88 of 100
📘 CLASS XI
Select the correct statements regarding chromosome classification:
I. Metacentric chromosome has two equal arms. II. Sub-metacentric chromosome has one shorter and one longer arm. III. Acrocentric chromosome has one extremely short and one very long arm. IV. Telocentric chromosome has a terminal centromere.
Which statements are correct?
Metacentric, sub-metacentric, acrocentric, and telocentric chromosomes are classified based on the position of the centromere, and all four statements are correct.
Question 89 of 100
📘 CLASS XI
Consider statements regarding enucleated cells in mature organisms:
I. Mammalian erythrocytes lack a nucleus at maturity. II. Vascular plant sieve tube cells lack a nucleus at maturity. III. Both RBCs and sieve tube cells are living functional cells. IV. Enucleated cells undergo rapid meiotic divisions continuously.
Which statements are correct?
Mature mammalian erythrocytes and sieve tube cells lack nuclei but remain living and functional. Statement IV is incorrect because enucleated cells cannot undergo cell division.
Question 90 of 100
📘 CLASS XI
Read statements regarding nucleolus features:
I. Not bound by a membrane. II. Continuous with nucleoplasm. III. Site of active rRNA synthesis. IV. Larger in cells active in protein synthesis.
Which statement combination is correct?
The nucleolus is a non-membrane-bound structure that is continuous with the nucleoplasm, synthesizes rRNA, and is larger and more numerous in cells actively synthesizing proteins.
