Which of the following traits may be considered in marriage counseling?

Step 1: Analyze the question Marriage counseling in biology focuses on inherited traits that could cause health problems for a couple's children. The traits usually considered are blood group compatibility (Rhesus factor), genotype (e.g., sickle cell: AA, AS, SS), and genetic diseases.

Step 2: Explain the concept The Rhesus factor (Rh) is a protein on red blood cells.

• Rh positive (Rh⁺) has the protein.
• Rh negative (Rh⁻) lacks it.

If an Rh⁻ mother carries an Rh⁺ baby (inherited from an Rh⁺ father), her body may produce antibodies against the baby's red blood cells. This usually does not affect the first pregnancy, but it can seriously harm later pregnancies. It causes haemolytic disease of the newborn (erythroblastosis fetalis), where the baby's red blood cells are destroyed, leading to anaemia, jaundice, or even death.

Couples are therefore counseled on Rhesus compatibility before marriage so that preventive medical care can be planned.

Step 3: Evaluate the options

• A. Height: Not a health risk to offspring. It is influenced by genes and environment, and has no medical importance in counseling.
• B. Fingerprints: Used for identification (forensics), not for compatibility.
• C. Rhesus factor: Directly affects the health of children, so it is considered in marriage counseling. ✔
• D. Colour of skin: Has no bearing on the health of the couple or their children.

Step 4: Answer The correct option is C. Rhesus factor.

Exam tip: Remember the "big three" of marriage counseling: Genotype (sickle cell), Blood group/Rhesus factor, and hereditary diseases. If you see these in the options, pick them over physical features like height, skin colour, or fingerprints.