What is true about ribosomes?
The prokaryotic ribosomes are 80S, where S stands for sedimentation coefficient.
These are composed of ribonucleic acid and proteins
These are found only in eukaryotic cells
These are found only in eukaryotic cells
Select the correct statement from the following regarding cell membrane.
Na+ and K+ ions move across cell membrane by passive transport
Proteins make up 60 to 70% of the cell membrane
Lipids are arranged in a bilayer with polar heads towards the inner part
Lipids are arranged in a bilayer with polar heads towards the inner part
Which one of the following structures is an organelle within an organelle?
Ribosome
Peroxisome
ER
ER
Which one of the following cellular parts is correctly described?
Thylakoids - flattened membranous sacs forming the grana of chloroplasts
Centrioles - sites for active RNA synthesis
Ribosomes - those on chloroplasts are larger (80s) while those in the cytoplasm are smaller (70s)
Ribosomes - those on chloroplasts are larger (80s) while those in the cytoplasm are smaller (70s)
The structures that are formed by stacking of organized flattened membranous sacs in the chloroplasts are
cristate
grana
stroma lamellae
stroma lamellae
The chromosomes in which centromere is situated close to one end are
metacentric
acrocentric
telocentric
telocentric
Select the correct matching in the following pairs
Smooth ER — Oxidation of phospholipids
Smooth ER — Synthesis of lipids
Rough ER — Synthesis of glycogen
Rough ER — Synthesis of glycogen
C.
Rough ER — Synthesis of glycogen
Smooth ER-synthesis of lipids is correct match.
Endoplasmic Reticulum (ER) is a network of tubules and flattened sacs in the cell. It is responsible of manufacturing and packaging system. There are two regions of ER as
(i) Rough Endoplasmic Reticulum (RER) It contains ribosomes on its membrane so it synthesis only proteins and also transfer them wherever these are required.
(ii) Smooth Endoplasmic Reticulum (SER) It is smooth because of lack of ribosomes around its membrane. It is involved in the synthesis and storage of lipids, fats, sterols and glycogen etc.
Which one of the following is not an inclusion body found in prokaryotes?
Phosphate granule
Cyanophycean granule
Glycogen granule
Glycogen granule