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
B.
acrocentric
Acrocentric chromosome has centrosome, which is situated almost closed to an end.
There are 4 types of chromosomes according to location of centromere on chromosome (chromatid arms) as
1. Metacentric X-shaped chromosomes with centromere exactly at the middle of two arms
Chromosomes 1 and 3 are metacentric.
2. Acrocentric When one arm is short and centromere is inner to telomere. It is hard to observe short arm but still it is present.
Chromosome 13, 14, 15, 21 and 22 are acrocentric.
3. Submetacentric: Centromere is sub median, so Arm's length are unequal but observable. Chromosomes 4 and 12 are submetacentric.
4. Telocentric: When centromere is located at the terminal end of the chromatid arm.
Human do not possess telocentric chromosome.
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
Which one of the following is not an inclusion body found in prokaryotes?
Phosphate granule
Cyanophycean granule
Glycogen granule
Glycogen granule