What are Traits?

A  trait is a distinct feature or quality. There are two types of traits.

Inherited traits are characteristics that are passed down by the parent, so that the offspring also has that trait. Examples of inherited traits include fur color (dogs pass down the color of their fur). Human traits include freckles, eye color, hair color,etc.

Acquired traits are characteristics that are not passed down by the parent. Instead, it is a trait affected by the environment. For example, many birds can sing at an early age. The song becomes more complex as it hears other birds sing. Practicing something makes you better at it. Another example is the color of a flamingo. Flamingos are born with white feathers. Flamingos get their red color from the food they eat.

Dominant and Recessive Traits

Traits can be dominant or recessive. The dominant trait prevents the recessive trait from showing. In other words, dominant traits are shown in the organism, and recessive traits are hidden. Recessive traits appear in later generations. For example, if a plant had a tall and short trait, it would grow tall, because that is the dominant trait. Some of the offspring of the plant would grow short.

Genes

Genes are located in chromosomes, and control different traits. Chromosomes are structures located in a nucleus that contain directions for the cell.

The genotype of an organism is all the genes inherited by an organism. For example, the genotype of an organism could be two dominant genes, two recessive genes, or one dominant and one recessive gene.

The phenotype is the way in which an organism shows its traits. For example, if a plant had a tall and a short trait, the phenotype would be the tall trait, since it is dominant.

X and Y Chromosomes

The x and y chromosomes determine the gender of the organism. X is female, and Y is male. The egg always has an X chromosome. The gender depends on what chromosome the sperm has (if the sperm has X it is female, and if it has Y it is male).

What is a Pedigree?

A pedigree is a chart that tracks the history of a trait. In a pedigree, male members of the family are represented as a square. Female members are represented as a circle. Family members with the dominant trait are shaded a dark color. Family members with the recessive trait are shaded a lighter color that those with the dominant trait.