A bacterium divides every 35 minutes. If a culture containing 10⁵ cells/mL is grown for 175 minutes, what will be the cell concentration/mL after 175 minutes?

(1) 5 × 10⁵ cells

(2) 35 × 10⁵ cells

(3) 32 × 10⁵ cells

(4) 4.175 × 10⁵ cells

Dikaryotisation (n + n) in Agaricus is brought about by

(1) clamp connections

(2) somatogamay between two hyphae of different strains

(3) Both (1) and (2) are correct

(4) basidiospores

'Red tide' is caused by

(1) Gonyaulax

(2) Ceratium

(3) Triceratium

(4) All of these

Which one of the following shows heterothallism?

(1) Rhizopus

(2) Bacterium

(3) Cycas

(4) Ricinus

Which of the following is a 'cyanophage'?

(1) S-13

(2) $\varphi \times 174$

(3) SV-40

(4) LPP-1

The common characteristic showning by mushroom, smut and rust

(1) is characterised by presence of basidiocarps

(2) is characterised by presence of ascocarps

(3) all are pathogen

(4) all are saprophytic in nature

Which one exhibits the character of a protozoan during one phase of its life cycle and character of fungi in another phase of its life cycle?

(1) Water moulds

(2) Psilophytes

(3) Slime moulds

(4) Diatoms

Spirochaetes is/are

(1) a class of viruses

(2) myxobacteria

(3) spiral-shaped bacteria

(4) richittsias

Which of the following organisms completely lack cell wall, they are the smallest living cells known and can survive without oxygen?

(1) Mycoplasma

(2) Euglenoids

(3) Slime moulds

(4) All of these

Spirochaetes is are

(1) a class of insects

(2) a class of viruses

(3) bacteria

(4) fungi