0 a mischievous, usually dirty or ragged, child, especially a boy -- uličník
He was chased by a crowd of urchins.
Activation of amino acid uptake at fertilization in the sea urchin egg.
A variety of methods has been developed to prevent formation of fertilisation membranes in sea urchin eggs.
The hyaline layer is a collagen-containing extracellular matrix in sea urchin embryos and reaggregating cells.
Most of this work has been done with model organisms, especially sea urchins, but many of the principles governing fertilisation appear to be generally applicable.
Visually he was more iconic than the other street urchins in the comic and was the only character to look at and address readers directly.
In the present study about 20% of mouse oocytes were activated following injection of 10 sea urchin spermatozoa.
A localized zone of increased conductance progresses over the surface of the sea urchin egg during fertilization.
Proteolysis of the major yolk glycoproteins is regulated by acidification of the yolk platelets in sea urchin embryos.
