Biological Sex Determination

Where can you find DNA?

• In reproductive cells only

• In brain cells only

• In blood cells only

• In practically every cell in your body

What is the relationship between chromosomes and DNA?

• DNA contains chromosomes

• Chromosomes are made out of DNA

• Each chromosome contains a small piece of a DNA molecule

• One pair of chromosomes makes up a full DNA molecule

How is the 23rd pair of chromosomes different in males than it is in females?

• Males are XX, females are XY

• Males are XX, females are YY

• Males are XY, females are XX

• Males are YY, females are XX

Why do chromosomes come in pairs?

• One pair is for the left half of your body, the other is for the right half

• Each chromosome has a backup copy

• One of each pair comes from your biological mother, the other from your biological father

• One chromosome contains your parents' DNA, the other contains your own DNA

In what crucial way are egg and sperm cells different from other cells in the body?

• They have only a single set of chromosomes (instead of a pair of each chromosome)

• They can move

• They have a limited lifespan

• Their chromosomes do not contain DNA

In what way are the 23rd chromosomes of sperm and egg cells different?

• Sperm cells contain either X or Y chromosomes; egg cells contain X chromosomes only

• Sperm cells contain X chromosomes only; egg cells contain either X or Y chromosomes

• Sperm cells contain Y chromosomes only; egg cells contain either X or Y chromosomes

• Sperm cells contain either X or Y chromosomes; egg cells contain Y chromosomes only

What is a haploid cell?

• A cell that determines one's gender

• A cell that contains no DNA

• A cell with half the normal (diploid) number of chromosomes

• A cell with double the normal number of chromosomes

What random factor determines a baby's biological sex?

• Whether the egg contains an X or Y chromosome

• Whether the sperm contains an X or Y chromosome

• Whether the sperm is diploid or haploid

• Whether the egg is diploid or haploid

If a sperm with an X chromosome fertilizes an egg, what is the probability that the offspring is biologically female?

• 0 percent

• 25 percent

• 50 percent

• 100 percent

Which of these 23rd chromosome combinations (a chromosomal mutation) is likeliest to result in a person with male and female traits?

• XXX

• X0

• XY

• XXY