Amoeba obtains its oxygen requirements

A. from oxidising food substances

B. from air trapped in vacuoles

C. through diffusion of air into its body

D. through an air cavity in the ectoplasm

Which of the following best describes a colony of volvox?

A. Asexually reproduced cells held together in a mass, but independent of each other

B. Sexually reproduced cells held together in a mass, and dependent on each other

C. Single free-living acellular units irrespective of their parental origin

D. Several units of cells, held together by cytoplasmic strands and dependent on each other

The hydra has two body layers of cells called

A. ectodermis and enteron

B. ectodemt and endoderm

C. endodermis and dermis

D. epidermis and dermis

All the following organelles have membranes except

A. nucleus

B. vacuole

C. cell membrane

D. cell wall

Which of these has the most complex level of organization?

A. Euglena

B. Hydra

C. Heart

D. Virus

The unit contained in a cell structure responsible for changes in form and shape of organisms is called

A. mitochondria

B. gene

C. ribosome

D. lysosome

The plant cell mostly stores food as

A. glycogen

B. auxins

C. homtones

D. starch

The presence of a large member of mitochondria in a cell indicates that

A. it has little cytoplasmic content

B. the cell is very active

C. the cell is dormant

D. the respiration is poor

Which of the following statements is incorrect about diffusion?

A. It involves degradation of soluble particles in solvents

B. it occurs mainly in gaseous and liquid media

C. No membrane is needed to effect the movement of molecules

D. Molecules move from region of lower concentration to that of higher concentration.

In which of the following organisms is ammonia excreted as a waste product?

A. Man

B. Bird

C. Amoeba

D. Spirogyra

The following are the functions of supporting tissues in plant except

A. rigidity

B. flexibility

C. strengthening

D. secretory

Which of the following organisms has the largest surface area-to-volume ratio?

A. Man

B. Earthworm

C. Amoeba

D. Grasshopper