Blood relations: Reasoning Ability Notes for Uttar Pradesh TET (Teacher Eligibility)

Blood Relations – Study Notes

(Uttar Pradesh TET – Reasoning Ability)

1. Simple Explanation

Blood relations (also called kinship or family relations) are the connections that exist because of common ancestry.
They are classified into two broad categories:

Category	Definition	Example
Lineal (Direct)	Descent from a common ancestor in a straight line (parent → child → grand‑child, etc.)	Father‑son, mother‑daughter, grandfather‑granddaughter
Collateral (Indirect)	Share a common ancestor but are not in a straight line (siblings, cousins, aunts/uncles, etc.)	Brother‑sister, cousin‑cousin, uncle‑nephew

Rules for determining relations

Same parent → Siblings
Same grand‑parent but different parents → Cousins
Parent’s sibling → Uncle/Aunt
Child of a sibling → Nephew/Niece
Grandparent’s sibling → Great‑uncle / Great‑aunt
Grandchild of a sibling → Great‑nephew / Great‑niece
Marriage connections (in-laws) are not blood relations – they are affinal relations.

2. Key Points

Point	Details
Terminology	- Direct Line: Father, Mother, Son, Daughter, Grand‑father, Grand‑mother, etc. - Collateral Line: Brother, Sister, Uncle, Aunt, Nephew, Niece, Cousin, Great‑uncle, Great‑aunt, etc.
Common Ancestors	- Parent → 1 generation back. - Grand‑parent → 2 generations back. - Great‑grand‑parent → 3 generations back.
Siblings	- Full siblings share both parents. - Half siblings share only one parent.
Cousins	- First cousins share grandparents. - Second cousins share great‑grandparents, etc.
Uncles & Aunts	- Paternal (father’s side) vs Maternal (mother’s side). - Great‑uncle / Great‑aunt: sibling of a grandparent.
Directional Cues	Use “first,” “second,” “great‑” to indicate distance from the common ancestor.
Notation	Use parent → child arrows, or simple tables to map relationships.

3. Worked Example

Scenario
You are given a set of statements:

A is the son of B.
B is the brother of C.
C is the daughter of D.
E is the mother of A.
F is the wife of B.
G is the son of C.

Question: Find the relationship between G and E.

Step‑by‑Step Reasoning

Step	Relation	Explanation
1	A is B’s son.	Straight line (parent → child).
2	B is C’s brother.	Same parents → siblings.
3	C is D’s daughter.	Parent → child.
4	E is A’s mother.	Parent → child.
5	F is B’s wife.	Affinal (not a blood relation).
6	G is C’s son.	Parent → child.

Build the family tree

          D
          |
          C (daughter of D)
         / \
        G   ... (other children)
          |
          (none)

B and C are siblings → B is C’s brother.
A is B’s son → A is C’s nephew.
E is A’s mother → E is A’s mother, so E is the grandmother of G (because G is C’s son → G is B’s nephew’s son).

Conclusion:
G is the grandson of E.
Or, equivalently, E is the great‑grandmother of G? Wait, check again.

E → mother of A.
A → son of B.
B → brother of C.
C → mother of G.

So the lineage:
E → A → B → C → G? No, that's wrong: A is B’s son; C is B’s sister; G is C’s son.
Thus E is A’s mother; A is B’s son; B is sibling of C; C is parent of G.

Therefore E is G’s great‑aunt? Let's re‑trace:

G’s parent: C.
C’s sibling: B.
B’s child: A.
**