Biology Topic Practice
Chromosomes & DNA
The nucleus of a cell contains chromosomes made of DNA molecules. Each chromosome carries a large number of genes.
How many pairs of chromosomes are in a human body cell?
What is Chromosomes & DNA?
"A chromosome is a thread-like structure of nucleic acids and protein found in the nucleus, carrying genetic information."
Question 1
What is produced by mitosis?
Question 2
Chromosomes in the nucleus are made of:
Question 3
Before a cell divides by mitosis, what must happen to its DNA?
Genetic Packaging
In body cells, the chromosomes are normally found in pairs.
Human body cells have 23 pairs (46 total) of chromosomes.
Genes are small sections of DNA that code for specific proteins.
Exam Tip
Sex cells (gametes) only have 23 single chromosomes, not pairs.
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