Question

Which one of the following diseases is inheritable?

• A. Leukaemia
• B. Colour blindness
• C. Malignancy
• D. Hepatitis

Hint:

Look for the condition carried on a sex chromosome and passed directly from parent to child.

Answer 1

The Correct Option is B

Step 1: Understanding the Question.
An inheritable, or hereditary, disease is one that is caused by a faulty gene and is passed down from parents to children through reproduction. The question asks which of the four listed conditions fits that definition.

Step 2: Key Fact.
Colour blindness is a classic example of a sex linked inherited disorder. The gene for normal colour vision sits on the X chromosome. A faulty copy of this gene is passed from parent to child, which is why colour blindness runs in families and appears more often in sons than daughters.

Step 3: Detailed Explanation of Other Options.
Leukaemia, option (A), is a cancer of blood forming tissue. Most cases arise from mutations picked up in the body's own cells during a person's life, rather than being passed down as a fixed inherited trait, so it is not classed as a simple inheritable disease here. Malignancy, option (C), is the general term for cancerous growth. Like leukaemia, it usually results from mutations that build up in a person's cells over time due to factors such as radiation, chemicals or ageing, not from a gene handed down in a fixed pattern from parent to child. Hepatitis, option (D), is inflammation of the liver, most often caused by a virus such as hepatitis A, B, C, D or E, so it is an infectious disease that spreads from person to person, it is not inherited through genes.

Step 4: Final Answer.
Among the four options, only colour blindness is passed down through genes from parent to offspring.
\[ \boxed{\text{Colour blindness}} \]