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Flashcards · Biology · Cell Division

Chromosomes, Genes and DNA

17 cards

  1. Where are the chromosomes in a human body cell?

    In the nucleus.

  2. What is a chromosome made of?

    A long molecule of DNA, coiled up.

  3. What does each chromosome carry?

    A large number of genes.

  4. What is a gene?

    A short section of DNA that contains the instructions for making one protein.

  5. What shape is a DNA molecule?

    A double helix: two strands twisted around each other.

  6. How many chromosomes are there in a human body cell?

    46, arranged as 23 pairs.

  7. Where does each chromosome in a pair come from?

    One from the mother and one from the father.

  8. A cell has 12 pairs of chromosomes. How many chromosomes is that?

    24.

  9. A cell has 20 chromosomes. How many pairs is that?

    10.

  10. Which is bigger, a gene or a chromosome?

    A chromosome. A gene is only a short section of one.

  11. Which pair of chromosomes decides whether a person is male or female?

    The sex chromosomes: XX in females and XY in males.

  12. What is a genome?

    All of the genetic material of an organism.

  13. Does a bigger number of chromosomes mean a more complex organism?

    No. A dog has 78 and a human has 46.

  14. True or false: a gene contains several chromosomes.

    False. A chromosome carries several genes.

  15. A cell, nucleus, chromosome and DNA diagram with a pointer marked X to the chromosome. What is the structure marked X in this diagram?

    A chromosome: a long, coiled molecule of DNA that carries a large number of genes.

  16. Four zoom circles from a cell to a stretch of DNA, with nothing labelled. Name each level from the cell down to the gene. The same four zoom circles with every level named.

  17. How many chromosomes are there in a human body cell, and how are they arranged? Twenty-three pairs of chromosomes, one pink and one blue in each pair.

    46, arranged as 23 pairs. One chromosome in each pair came from each parent.