IGCSE Biology Paper-1: Specimen Questions with Answers 163 - 164 of 208

Question 163

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Question

MCQ▾

The diagram shows blood as seen under a microscope.

Identify Parts W, X, Y and Z

Identify Parts W, X, Y and Z

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Which identify parts W, X, Y and Z of the blood?

Choices

Choice (4)
a.plasma-X, platelet-W, white blood cells-Y, red blood cells- Z
b.plasma-W, platelet-Z, white blood cells-Y, red blood cells- X
c.plasma-W, platelet-Z, white blood cells-X, red blood cells- Y
d.plasma-X, platelet-W, white blood cells-Z, red blood cells- Y

Answer

a.

Explanation

A blood smear is a sample of blood that’s tested on a specially treated slide. For a blood smear test, a laboratory professional examines the slide under a microscope and looks at the size, shape, and number of different types of blood cells. These include:

  • Red blood cells, which carry oxygen from your lungs to the rest of your body
  • White blood cells, which fight infection
  • Platelets, which help your blood to clot
Red Blood Cells

Red Blood Cells

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Question 164

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Question

MCQ▾

Back cross is a cross between

Choices

Choice (4)
a.
b.
c.
d.

Answer

b.

Explanation

Back Cross

  • It is a cross which is performed between F1 hybrid and one of its parents.
  • If cross is performed between F1 hybrid and dominant parent, then it is called ‘Out cross’ All the offspring’s obtain from this cross have dominant characters. Thus, F1 generation can be analyzed through this cross.
Dihybrid Test Cross

Dihybrid Test Cross

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Test Cross

Cross is performed between F1 hybrid and recessive parent. It is a cross to know whether an individual is homozygous or heterozygous for dominant character.

Dihybrid Test Cross

Dihybrid Test Cross

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Dihybrid Test Cross

Dihybrid Test Cross

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