Diatoms have left behind large amounts of cell wall deposits in their habitat because:
1. They are most abundant in that habitat
2. Their life span is long
3. Their wall is indestructible
4. The statement is not true
Members of Kingdom Protista:
1. are primarily aquatic
2. do not have membrane bound organelles
3. are all ciliated or flagellated
4. reproduce exclusively by asexual means
Select the wrong statement.
(1) The walls of diatoms are easily destructible
(2) 'Diatomaceous earth' is formed by the cell walls of diatoms
(3) Diatoms are chief producers in the oceans
(4) Diatoms are microscopic and float passively in water
In which group of organisms the cell walls form two thin overlapping shells which fit
together?
1. Chrysophytes
2. Euglenoids
3. Dinoflagellates
4. Slime moulds
Diatoms do not decay easily because
1. they have siliceous walls
2. their body is impervious to water
3. they are chitinous
4. they are abundant in saline soil
Which of the following feature does not hold true for chrysophytes?
(1) Golden algae
(2) Fresh water and aquatic both habitat
(3) Active floating in water
(4) Microscopic
Which of the following features does not go with characteristics of chrysophytes
(1) Diatoms + Desmids
(2) Rarely photosynthetic
(3) Plankton
(4) Found in both type of aquatic habitat ie marine and fresh water
Diatoms do not possess this character-
(1) Two thick overlapping shell
(2) Soap box type arrangement of cell walls
(3) Indestructible cell walls
(4) Leave cell wall deposits
Diatomaceous earth is a result of accumulation of cell wall deposits of diatoms over
(1) Billions of years
(2) Millions of years
(3) Thousands of years
(4) Hundreds of years
Which of the following feature is not associated with diatoms?
(1) Chief producers of Earth
(2) Form diatomaceous earth which has gritty soil
(3) Gritty soil is used in filtration
(4) Gritty soil is used in polishing