Essential Idea: Chromosomes carry genes in a linear sequence that is shared by members of a species


Q1+2. The table lists the structures containing genetic material:

  Plasmid Histones DNA Chromosomes
A ✔︎ X ✔︎ one
B ✔︎ X ✔︎ 46
C X ✔︎ ✔︎ 23
D X ✔︎ ✔︎ 46
1. Which letter describes the genetic material in a bacterium?
2. Which letter describes the genetic material in a human somatic cell?
3. The diagram shows a chromosome during cell division.

Condensed Eukaryotic Chromosome

Edit of image by Zephyris
CC-BY-SA 3.0

Select the correct answer for labels X and Y.

  X Y
A chromosome chromatid
B chromatid centromere
C centromere chromatid
D centriole chromosome

Q4-5: Complete the following sentences:

The number of chromosomes in a normal cell of a plant or animal is (known as) .
A sex cell has where n is the number of different sets of chromosomes.

Q6-8 The image shows a karyogram from the cell of a person.

blood cells with sickle cell anemia

Wessex Reg. Genetics Centre
CC-BY-SA 4.0

6. The karyogram shows homologous chromosomes. Homologous chromosomes are...
  • A. two chromosomes with differing sets of genes, in the same sequence, with the same alleles
  • B. two chromosomes with the same set of genes, in a different sequence, with the same alleles
  • C. two chromosomes with a different set of genes, in the same sequence, with different alleles
  • D. two chromosomes with the same set of genes, in the same sequence, sometimes with different alleles

7.  Which statement correctly identifies the characteristics of this person?

  • A. Normal female
  • B. Female with Down’s syndrome
  • C. Normal male
  • D. Male with Down’s syndrome
8. When pairing up chromosomes to make a karyogram which features are used?
  • A. Size of Chromosome only
  • B. Size of chromosome and position of the centromere
  • C. Size of the chromosome, position of the centromere and the banding
  • D. Size of Chromosome and banding
9. Which of the following is a characteristic of the human Y chromosome?
  • A. It is the largest chromosome in the human karyotype
  • B. It contains some genes that are not present on the X chromosome
  • C. It is 1/3 size of the X chromosome
  • D. It is made of DNA and histones covered by phospholipids
10. Which of these techniques was used to establish the length of DNA molecules in a chromosome?
  • A. Chromatography
  • B. Autoradiography
  • C. Microscopy
  • D. Karyotyping