Granal plastids in the cotyledons of the dry embryo of Kochia childsii

The green cotyledons of the dry embryo of Kochia childsii contain chlorophyll and granal chloroplasts. Epidermal chloroplasts differ from other chloroplasts of the cotyledons in having large electron-dense inclusions and a less well defined internal membrane system. Although chloroplast dimorphism is established during germination, the internal membrane systems of mesophyll and bundle sheath chloroplasts are similar ultrastructurally in the dry cotyledon.

Extracellular production in relation to growth of four planktonic algae and of phytoplankton populations from Lake Ontario

In four species of planktonic algae both carbon fixation and excretion on an ash-free dry weight basis increase with relative growth rate (K) of the culture measured in log10 units. In natural populations percentage excretion values are positively correlated with K values; however, environmental factors may be of relatively greater importance and determine the extent of excretion.