Artificial kidney – dialysis machine Illustration Play

Artificial kidneys Whiteboard exercise Play

Artificial kidneys and kidney transplantation Student activity Play

Artificial respiration Animation Play

Artificial selection Slideshow Play

Artificial sweeteners Illustration Play

Ascaris lumbricoides infection Slideshow Play

Ascomycota Illustration Play

Asexual reproduction Student activity Play

Asexual reproduction Student activity Play

Asexual reproduction Whiteboard exercise Play

Asexual reproduction Whiteboard exercise Play

Asexual reproduction in bacteria Animation Play

Asexual reproduction in cnidarians and polychaetes Animation Play

Asexual reproduction in cnidarians; platyhelminths and echinoderms Animation Play

Asexual reproduction in organisms Slideshow Play

Asexual reproduction in rotifers; nematodes and certain insects Animation Play

Asexual reproduction in sponges Animation Play

Associativity of vector addition Whiteboard exercise Play

Astigmatism Animation Play

Astronomical numbers Animation Play

Astronomical unit Animation Play

Asymmetry of the epithelial cell Slideshow Play

At least one boy in a family Whiteboard exercise Play

At the surface of water Animation Play

Atherosclerosis – the underlying cause of most cardiovascular diseases Student activity Play

Atherosclerotic lesions Slideshow Play

Atmospheric carbon dioxide Student activity Play

Atmospheric carbon dioxide Animation Play

Atmospheric pressure Slideshow Play