Leaf diseases of deciduous hardwood trees are grouped. into six categories, to simplify their identification, as follows 1. (See Figure 1a-f for a pictorial representation of the symptoms.) AnthracnoseâIrregular dead areas on leaf margins, between. and across and/or along veins, often moving onto the.
That depends on what organism the cell belongs to. A nucleus of a normal human cell contains 46 chromosomes, whereas this is a double chromosome set, i.e. we have 23 pairs of chromosomes that are used for the same functions. Two chromosomes that fulfill the same functions are called homologous.
Chromosomes and Genes. Chromosomes are the carriers of hereditary characteristics called genes. The human cell nucleus contains 46 chromosomes (diploidy) in the form of 23 chromosome pairs (23 male, 23 female chromosomes).very cell with the exception of red blood cells has a nucleus. However, there are cells with two nuclei (some liver cells) or greater numbers of nuclei, e. g., osteoclasts in bony tissue (5â20 nuclei) or skeletal muscle cells (more than 1000 nuclei). Cells without nuclei can no longer divide.