Question:

1. Name the following :

(i) Any two one - celled organisms.

(ii) The longest cells in ANIMALS.

(iii) Amoeboid cells in humans.

(iv) Shape of white. blood cells.

(v) A cell component which is visible only in cell DIVISION stages.

2. List three CATEGORIES of substances which are ensured greater diffusion DUE to large surface/volume ratio of the cells.

Answer:

1. (i) Amoeba, Paramecium

Unicellular organisms are those organisms which consists of a single cell only.

(ii) Nerve cell or neuron

Nerve cells HELPS in transferring the signals.

(iii) White Blood cells

These cells fight with the infectious organisms and protect our body.

(iv) Irregularly shaped

The shape of WBC is not fixed and is continuously changing.

(v) Chromosomes

Chromosomes are the thread - like structures which helps in transferring the characters from one generation to another.

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2. (a) The gases such as oxygen and carbon dioxide which can diffuse in and out of the cell.

(b) Waste materials generated by the cells also takes place through diffusion

(c) The villi present in small intestine absorb nutrients through diffusion.