Chromosomes

1. Karl Nageli and Hofmeister observed chromosomes in pollen mother cells of Tradescantia.
2. Chromosome name proposed by Waldeyer.
3. During cell division, chromatin threads become condensed to form thick structures called chromosomes.
4. Structure of chromosomes can be best studied at metaphase stage as chromosomes are most condensed.
5. Plant cell possess normally larger chromosomes then the animal cells. (Trillium have longest chromosomes 32 mm at metaphase).
6. Monocot plants have larger chromosomes as compared to dicot plants.
7. Haploid set of chromosomes alongwith all its genes are called genome. In somatic cells of animals and higher plants there are two genomes. Their gamets or gametophytic cells have one genome.