Prior to reading the article, teachers could also have students use a Vocabulary Preview learning strategy to engage their prior knowledge and introduce new terminology.(e.g., hemophilia, Duchenne's Muscular Dystrophy, etc.) This article could also serve as an introduction to the topic of sex-linked traits and disorders in humans. Before reading this article, teachers could begin by introducing the concepts of sex chromosomes and sex-linked inheritance.Concepts introduced include genetics, epigenetics, sex chromosome, X chromosomes, Y chromosomes, inactivated, lyonization, Barr body, physical traits, alleles and piebalding. This article can be used to support teaching and learning of Biology and Genetics related to DNA structure and heredity.This means that any cell in a female cat could have the combination X BX B, X BX b or X bX b. In tortoiseshell cats, there are two versions, or alleles, of this gene. In cats, the X chromosome carries a gene for fur colour. A cat with an X and a Y chromosome is male. Cats get one of these chromosomes from each parent. Like humans, cats have X and Y chromosomes that determine their biological sex. This colouring has to do with genes on the X chromosome. Let’s get back to cats! You may be familiar with the interesting pattern of orange and black found on tortoiseshell cats. How do tortoiseshell cats get their colours? These show up as bright spots when exposed to different fluorescent stains (Source: Crop from image by Stanley M Gartler, Kartik R Varadarajan, Ping Luo, Theresa K Canfield, Jeff Traynor, Uta Francke and R Scott Hansen via Wikimedia Commons). The arrows in the image above point to Barr bodies. The X-Y chromosome system can be found in most mammals, some insects, and even some types of plants! Because of this, one x chromosome needs to be inactivated in every cell of your body. Your cells cannot get their instructions from two different X chromosomes. But if you’re biologically female, things work a little differently. If you’re biologically male, then each of your cells get instructions from both chromosomes. While others are found on the Y chromosome. Men with Klinefelter syndrome have two X chromosomes and one Y chromosome (XXY).Ĭertain genes are found on the X chromosome. Women with Turner syndrome have only one chromosome (X). If you’re biologically male, you most likely got an X chromosome from your mother and a Y chromosome from your father.Įven though XX and XY are the two most common chromosomal combinations, others are possible.

If you’re biologically female, you most likely got an X chromosome from each parent. There are two types of sex chromosomes known as X chromosomes and Y chromosomes. Most of us get one sex chromosome from each parent. How do your sex chromosomes affect your cells? We can look at tortoiseshell and calico cats to understand this a little better. But did you know that the fur of some cats can be useful in understanding the branch of genetics called epigenetics? Epigenetics is the study of changes in gene expression due to factors other than changes to DNA.

There are millions of cat videos that can be found on YouTube from all over the world!Ībout 37% of Canadian homes have at least one cat.Ĭats can make us laugh, they can make good family pets, or they may even scare some of us. People love cats! And they are not just popular in Canada.

Tortoiseshell calico cat