IGCSE Biology Paper-2: Specimen Questions with Answers 201 - 202 of 203

Question 201

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Question

MCQ▾

Three cell structures are listed.

1. Cell wall

2. Cytoplasm

3. Nucleus

Which structures are found in epidermis cells and in skin cells?

Choices

Choice (4)
a.3 only
b.1 and 3
c.2 and 3
d.2 only

Answer

c.

Explanation

Epidermis

  • Each leaf bears upper and lower epidermis. Each of them consists of single layer of compactly arranged parenchymatous cells. It possesses all properties of a plant cell and one of the main one is having cell wall.
  • Hepatocytes make up about 80 % of the cells in the liver.
  • Are large polyhedral epithelial cells, with large round centrally located nuclei (2 or more? )
  • Grouped in interconnected plates that are arranged into thousands of small polyhedral lobules
  • Store glucose in the form of glycogen, also vitamin B12, folic acid and iron
  • Participate in the turnover and transport of lipids.
  • Synthesize some of the plasma proteins (albumin, α and β globulins, prothrombin, fibrinogen metabolize/detoxify fat
  • Participate in the turnover of steroid hormones.
  • Regulates cholesterol level
  • Secrete bile (up to 1 liter per day)

Question 202

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Question

MCQ▾

The drawing is of a magnified human liver cell.

The drawing is of a magnified human liver cell

The Drawing is of a Magnified Human Liver Cell

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What is structure X?

Choices

Choice (4)
a.Rough endoplasmic reticulum
b.Smooth endoplasmic reticulum
c.Mitochondrion
d.Nucleus

Answer

c.

Explanation

  • Hepatocytes display an eosinophilia cytoplasm, reflecting numerous mitochondria, and large amounts of rough endoplasmic reticulum and free ribosomes, cytoplasmic glycogen and lipid.
  • The average life span of the hepatocyte is 5 months; they are able to regenerate. Hepatocyte nuclei are round with dispersed chromatin and prominent nucleoli. Binucleate cells are also common. Hepatocytes are organized into plates separated by vascular channels (sinusoids), an arrangement supported by a reticulin network.
  • The endothelial cells have no basement membrane and are separated from the hepatocytes by the space of Disse, which drains lymph into the portal tract lymphatics. Kupffer cells are scattered between endothelial cells; they are part of the reticuloendothelial system and phagocytose.
Liver cell

Liver Cell

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