Smooth muscles are 

(1) involuntary, fusiform, non-striated

(2) voluntary, multinucleate, cylindrical

(3) involuntary, cylindrical, striated

(4) voluntary, spindle-shaped, uninucleate

Which of the following features is not present in Periplaneta americana?

(1) Indeterminate and radial cleavage during embryonic development

(2) Exoskeleton composed of N-acetylglucosamine

(3) Metamerically segmented body

(4) Schizocoelom as body cavity

The function of the gap junction is to 

1. performing cementing to keep neighbouring cells together

2. faciliate communication between adjoining cells by connecting the cytoplasm for rapid transfer of ions, small molecules and some large molecules

3. seperate two cells from each other

4. stop substance from leaking across a tissue