card
103

chromosomes

OLogy Series
biology
card
103

chromosomes

OLogy Series
biology

Chromosomes are tiny, spaghetti-like packages of information. Every cell of your body contains 23 pairs of them -- that's 46 in all. Each chromosome contains hundreds of genes. Your genes give your cells information about things like your hair color, eye color, and much more.

On average, how long does it take for a cell to make a copy of all its chromosomes?

a few minutes

a few hours

weeks and weeks!

Are you right?

Correct!

Before a cell splits, it copies its chromosomes, so that each of the two new cells will have a complete set. The whole cell division process is called "mitosis" (my-TOW-sis).

King Henry VIII chopped off his wife's head, because she never had a son. Why wasn't this her fault?

She had the rare "anti-prince" gene.

Queens give birth to daughters about 85 percent of the time.

A chromosome from the dad decides if the baby will be a boy.

Are you right?

Correct!

The dad, not the mom, passes on the chromosome that determines whether a baby will be a boy or a girl. The chromosome that makes a boy is the "Y chromosome."

Chimpanzees have the same number of chromosomes as humans.

Fact
or
Fiction
?

Fiction

Chimpanzees have 48 chromosomes, while humans have 46. Dogs have 78, fruit flies have 8, trout have 120, and tomatoes have 24.

Every gene is located on a specific chromosome.

Fact
or
Fiction
?

Fact

Each gene "lives" on a particular chromosome with hundreds of others. Scientists are still searching for the exact location of each of our 30,000 genes.

Chromosomes (KRO-muh-sohms)
Found: in the cell's nucleus
Shape: tightly curled up like steel wool
How many: 23 pairs (in humans)
Characteristics: half come from your mother and half from your father
Importance: contain all genetic information and determine whether an organism is male or female

Image credits: Kelvin Chan.