Arborjet > Diseases > Anthracnose. Anthracnose (leaf blight) is a fungus that winters on twig tissue on the tree. In the spring, spores are transported to new buds and shoots. The disease is enhanced by cool, wet conditions. Infected leaves develop tan to reddish brown lesions that extend along the veins of the leaf.
These tables give the total number of chromosomes (including sex chromosomes) in a cell nucleus. For example, human cells are diploid and have 22 different types of autosome, each present as two copies, and two sex chromosomes. This gives 46 chromosomes in total.
These cells contain half the number of chromosomes as body cells and are called HAPLOID Chromosomes come in pairs, called Homologous Pairs (or homologs). Imagine homologs as a matching set, but they are not exacly alike, like a pair of shoes. Diploid cells have 23 homologous pairs = total of 46. Haploid cells have 23 chromosomes (that are not paired) = total of 23. Homologous Chromosomes . Sex Determination. Chromosomes determine the sex of an offspring. In humans, a pair of chromosomes called SEX CHROMOSOMES determine the sex. If you have XX sex chromosomes - you are female. If you have XY sex chromosomes - you are male. During fertilization, sperm cells will either contain an X or a Y chromosome (in addition to 22 other ...