P5 Reproduction & Heredity Notes

Passing on of Characteristics from Parents to Young

Living things reproduce to ensure the continuity of their species.

During reproduction, parents pass on their traits (characteristics) to their young.

Heredity: The transmission of characteristics or traits from the parents to their young is called heredity.

The young of living things have some characteristics similar to their parents.

Concept	Definition
Continuity	The continuation of a species through reproduction
Heredity	The passing on of characteristics from parents to young
Traits / Characteristics	Features passed from parents to offspring (e.g., eye colour, blood type)

Heredity in Humans

We inherit our characteristics from both of our parents.

Hereditary information is contained in the nucleus of the sperm of our father.
Hereditary information is also contained in the nucleus of the egg of our mother.

Some characteristics that we inherit from our parents are easily observed while some are not.

Type of Characteristic	Description	Examples
Easily observed	Parts of our appearance	Height, skin colour, hair colour, type of thumb, dimples, double/single eyelids
Not easily observed	Cannot be seen from the outside	Blood type, genetic diseases

Important: Characteristics such as dyed hair, surgically modified dimples and eyelids cannot be passed on from parents to their young. These are acquired characteristics, not inherited ones.

Some characteristics such as our fingerprints and voice patterns are unique to us.

Family tree: A family tree can be used to show the occurrence of a characteristic from one generation to the next.

Heredity in Plants

Plants also pass on their characteristics (traits) to their young.

A young plant resembles its parents.

A young plant inherits the shape, size, colour of flowers and fruit, taste of fruit, and type of seeds of its parents.

A plant always bears flowers, fruit and seeds of a similar type to its parents.

Parent Plant Produces...	Young Plant Will Produce...
White flowers	White flowers
Sour fruit	Sour fruit
Round seeds	Round seeds

Key Takeaways

Reproduction ensures the continuity of a species.
Heredity is the passing on of traits from parents to young.
We inherit characteristics from both parents — via sperm (father) and egg (mother).
Some traits are easily observed (appearance), others are not (blood type, genetic diseases).
Acquired characteristics (dyed hair, surgery) cannot be inherited.
Fingerprints and voice patterns are unique to each individual.
A family tree tracks how characteristics pass through generations.
Young plants resemble their parents — inheriting flower colour, fruit taste, and seed type.

Reproduction & Heredity — Concept Overview

1

Reproduction ensures the continuity of a species.

2

Parents pass on their traits to young — this is called heredity.

3

Father (sperm) + Mother (egg) → Offspring inherits from both.

4

Traits can be easily observed (appearance) or not easily observed (blood type, diseases).

5

Acquired traits (dyed hair, surgery) cannot be inherited.

6

A family tree tracks how characteristics pass through generations.

7

Young plants resemble parents — inheriting flower colour, fruit taste, seed type.