Types of Plant Reproduction

20 min

Let's begin

Mugisha's grandfather is busy before the rains. In one field he plants maize grains. In another he pushes pieces of cassava stem into the soil. "Both will grow into new plants," he says. "But only one of them started from a seed."

How can a piece of stem become a whole new plant? Today you will learn the two types of reproduction in plants.

What is reproduction?

Reproduction means making new living things of the same kind. All living things grow old and die, so without reproduction a kind of plant would die out completely (become extinct).

Sexual reproduction

In sexual reproduction, a male sex cell and a female sex cell join. Sex cells are also called gametes. In flowering plants the male gamete is in the pollen and the female gamete (the egg) is in the ovule. Sexual reproduction needs flowers, pollination and fertilisation, and it makes seeds. The new plants are like their parents but not exactly the same: each one is a little different.

Examples: maize, beans, sorghum and wheat grown from seed.

Asexual reproduction

In asexual reproduction, there is only one parent. No gametes join and no pollination happens. Instead, a part of the plant, such as a stem, a root or a bulb, grows into a new plant. The new plants are exactly the same as the parent.

Examples: cassava and sugarcane from stem cuttings, bananas from suckers, Irish potatoes from tubers, onions from bulbs.

Comparing the two types

	Sexual reproduction	Asexual reproduction
Number of parents	Two (or two flowers)	One
Gametes join?	Yes	No
Flowers and pollination needed?	Yes	No
Starts from	A seed	A stem, root, sucker, tuber or bulb
Young plants	Similar to the parents, but each a little different	Exactly the same as the parent
Speed	Usually slower	Usually faster

Good points and bad points

Asexual: it is fast, and it keeps the good qualities of the parent exactly, so a farmer knows what the harvest will be like. No pollinators are needed. But all the plants are the same, so if a disease attacks one, it can destroy them all. Cassava diseases, for example, spread through infected cuttings, which is why farmers must plant clean, healthy stems.
Sexual: the young plants are all a little different, so some may survive a new disease or a drought. Seeds can be stored for a long time and spread far away. But it is slower and needs pollination.

Some plants can do both. Irish potatoes have flowers and can make seeds, but farmers plant tubers because the crop grows faster and is the same as the parent.

Tip

A-sexual = A single parent. Sexual = Seeds made from two Sex cells.

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Try it yourself

Which type of reproduction makes seeds?
How many parents are needed for asexual reproduction?
Sexual or asexual? (a) beans grown from seed (b) a banana sucker (c) pieces of sugarcane (d) maize grains
Why do farmers like asexual reproduction for bananas?
Give one danger of growing a whole field of identical plants.

Answers

Sexual reproduction.
One.
(a) sexual (b) asexual (c) asexual (d) sexual.
It is fast, and the new plants have the same good qualities as the parent.
One disease can attack and destroy all of them, because none is different enough to resist it.

Quick check

Mugisha's grandfather pushes pieces of cassava stem into the soil, and they grow into new plants. Which type of reproduction is this?

What you learned today

Sexual reproduction joins male and female gametes, needs flowers and pollination, and makes seeds with a little variety.
Asexual reproduction uses one parent and a part of the plant; the young plants are identical to the parent.
Asexual is fast and keeps good qualities; sexual gives variety that can help plants survive.

Sources and credits

Natural Sciences Grade 7, Chapter 3: Sexual reproduction (3.1 Reproduction in angiosperms), by Siyavula Education, Siyavula, CC BY 3.0, adapted by Ganzaa.

The exercises (Try it yourself and the practice questions) are written by Ganzaa.

1What is reproduction?

2Sexual reproduction

3Asexual reproduction

4Comparing the two types

5Good points and bad points