Functions
• Contain genes hence, transmit genetic information.
• Control synthesis of proteins, enzymes, hence regulate cell division, growth and metabolism.
• Satellite chromosomes produce nucleoli for synthesis of ribosomes.
• Sex chromosomes (e.g., X and Y) determine sex of individuals.
• Introduce variations through crossing over.
• Produce mutations due to change in gene chemistry.
- Nucleic acids are not present in
(a) ribosomes (b) mitochondria
(c) chloroplasts (d) peroxisomes. - Functional independence of mitochondria and chloroplast
from rest of the cellulose machinery is due to
(a) presence of double membrane
(b) presence of DNA and RNA
(c) occurrence of electron transport chain
(d) their symbiotic association with prokaryotic cells. - Microbodies are involved in the process of
(a) respiration (b) photorespiration
(c) lipid synthesis (d) protein folding. - Match column I with column II and select the correct option.
Column I Column II
A. Chromonema (i) Fine fibres of DNA protein
complex
B. Chromatid (ii) Coiled filament that makes
chromosome
C. Chromatin (iii) Point where chromatids
are attached
D. Centromere (iv) Identical halves of a
chromosome
(a) A-(iii), B-(i), C-(ii), D-(iv)
(b) A-(i), B-(iii), C-(iv), D-(ii)
(c) A-(iv), B-(ii), C-(iii), D-(i)
(d) A-(ii), B-(iv), C-(i), D-(iii) - Refer to the given figure and select the correct option for
A, B, C and D.
DCBA(a) A is impermeable to biomolecules.(b) Electron transport system is present in B.
(c) C has the enzymes for the synthesis of fatty acids.
(d) D is responsible for the paternal inheritance.- Select the incorrect statement.
(a) Different ribosomes of polyribosome are connected
by thick strand of mRNA.
(b) New chloroplasts arise by the division of proplastids.
(c) Microtubules take part in endocytosis and are contra-
ctile elements of muscles.
(d) Microfilaments are solid structures made of actin proteins. - Select the correctly matched pair.
(a) Nucleolus - Double membrane
(b) Centriole - Without membrane
(c) Ribosome - Single membrane
(d) Glyoxysome - Without membrane - Identify the cytoskeletal structure from the following
statements.
I. It is a solid filament absent in unicellular eukaryotes.
II. It is unbranched and have thickness of about 10 nm.
III. It provides mechanical strength to axons and dendrons.
IV. It protects skin from abrasions.
(a) Microtubule (b) Microfilament
(c) Intermediate filaments (d) Both (a) and (b) - Which of the following helps in the formation of new
centrioles?
(a) Centriolar DNA (b) Nuclear DNA
(c) Kinoplasm (d) Pericentriolar satellite - Given diagram represents the process of formation of
ribosomes and its dimer.
Select the correct statement in support of this process.