GLOSSARY 



195 



Meristematic cells are those which divide to form new cells, i.e., the cells 



in the cambium and the tips of stems and roots. 

 The micropyle is a small pore in the seed coat below the hilum through 



which the pollen tube enters the seed coat. 

 A molecule is the smallest particle of any compound, i.e., H2O, or 



CeHizOe. 

 Monocotyledonous seeds have a single seed leaf, i.e., in the embryo of 



corn, Figure 1. 

 Mutations are sudden changes or variations in organisms caused by 



changes in the chromatin and therefore are transmitted by all later 



cell divisions. 

 Mycorrhiza is a symbiotic fungus which grows on the outside In the form 



of a mantle and Into the root either between the cells or into the 



cells, of many plants, chiefly the woody types. 

 A node Is the part of a stem from which one or more leaves and buds 



grow. 

 The nucleus is the part of a cell containing the chromatin of the cell. 



It appears to have certain special functions necessary to the life of 



the cell. 

 Osmosis is the diffusion of molecules through a membrane. In the plant 



the membrane is one of cytoplasm inside the cell wall. 

 The ovary is the basal portion of the female organ of a flower in which 



the seeds will grow. 

 The pericycle is a layer of cells in stems and roots between the phloem 



and the cortex. 

 The petiole is the stem-like structure of a leaf by which it is attached 



to the stem. 

 The phloem is a group of elongated cells, usually outside the cambium, 



which conducts food material. 

 Photosynthesis is the making of sugar by the use of the energy from 



light, using water and carbon dioxide as the raw materials. This 



can take place only in the presence of active chlorophyll. 

 Plumule is that small portion of the embryo of the seed which develops 



into the shoot of the plant. 

 Polyploidy refers to multiples of the normal number of chromosomes for 



a given species. 

 To propagate means to multiply or increase the number of organisms. 

 The protoplasm is the living matter of a cell, consisting of the nucleus 



and the cytoplasm. 

 The radicle is that part of the embryo of a seed which becomes or 



develops as the root of the seedling. 



