There is more than one meaning for "tend " and "prone to"
Meanings of "tend"
aid, attendance, attention, care, remedy, tending, therapy, treatment,
attend, be inclined to, be inclined towards, have a tendency to, incline to, incline towards, lean to, lean towards, look after, medicate, nurse, treat.
Meanings of "prone to" = likely to do something OR be affected by something, vulnerable.
Examples:
1.The coastal region is prone to earthquakes.
2.prone to do something: He’s prone to gain weight.
3.error-/injury-prone: He's an injury-prone football player