A: In a plant cell the vacuole helps in storing water, air or food
materials. It may also store primary or secondary metabolites. In a
plant cell the tonoplast facilitates the transport of a number of ions
and other materials against concentration gradient (from low
concentration to high concentration) into a vacuole. Hence the
concentration is higher in vacuole than in the cytoplasm.
Q: What does 'S' refer in a 70S and 80S ribosome?
A: 'S' refers to sedimentation coefficient and it is expressed as Svedberg unit.
Q: Mention a single membrane bound organelle which is rich in hydrolytic
enzymes.
A: Lysosomes.
Q: What are gas vacuoles? State their functions.
A: Gas vacuoles are the vacuoles that store air or gases. They are
generally found in blue green, purple and green photosynthetic
bacteria. They help the bacteria to float on water (buoyancy).
Q: What is referred to as satellite chromosome?
A: The chromosome with a non-staining secondary constriction is called
a satellite chromosome. This chromosome shows a small rounded
structure at the end due to secondary constriction which is called a
satellite.
Q: What are microbodies? What do they contain?
A: Peroxysomes and glyoxysomes are called microbodies. Peroxysomes
contain enzymes involved in catabolism of fatty acids, synthesis of
phospholipids and photorespiration. Glyoxysomes contain enzymes of
glyoxylate cycle.
Q: What is middle lamella made of? What is its functional significance?
A: Middle lamella is made up of calcium pectate. It holds the
neighbouring cells together (works as cementing material between two
cells.)
Q: Which part of the bacterial cell is targeted in gram staining?
A: Cell envelop.
Q: Which of the following is correct?
a) Cells of all living organisms have nucleus.
b) Both animal and plant cells have a welldefined cell wall.
c) In prokaryotes, there are no membrane bound organelles.
d) Cells are formed de novo from abiotic materials.
A: c) In prokaryotes, there are no membrane bound organelles.
No comments:
Post a Comment