Chromosomes are thread-like molecules that carry genetic information in the form of genes. Chromosomes are made of chromatin, which consists of DNA and proteins. In order to get the chromosomes packaged so tightly, DNA is wrapped around histones which forms nucleosomes. The nucleosomes are condensed and packaged into a chromosome. In humans, there are 46 chromosomes and 46 chromatids. During Interphase, the chromosomes are duplicated. There are still 46 chromosomes but there are now 92 chromatids. Most human body cells have 46 chromosomes. Humans have 22 of these chromosome pairs, called autosomes (meaning that they are not related to your biological sex).The 1 other pair is your sex chromosomes, which determine your biological sex. Females have two x-chromosomes and males have one x-chromosome and one y-chromosome.
So, is it possible for you to see all 46 of your chromosomes? Yes, you could through a karyotype! A karyotype is an image of all your chromosomes. In a karyotype, the chromosomes are made visible through staining. The chromosomes are typically from cells that are in a mitosis stage, more specifically metaphase because the chromosomes are condensed. The chromosomes in a karyotype are generally arranged in homologous pairs, with one chromosome from mom and one chromosome from dad. Homologous chromosomes are pairs of chromosomes that contain the same genes but not necessarily the same alleles. |