Parts of a Fruit and Their Functions - With Diagrams

Fruits in flowering plants can vary greatly in terms of appearance, taste and other characteristics. Many of them can be consumed by humans, but others may be unpleasant or even toxic. The disparity in terms of physical form can be seen when we compare a banana with a blackberry. Despite such fruits appearing completely different, they both share the basic anatomy which allows them to carry out their various functions.

Before we look at the individual parts of a fruit, we can look at what the main functions of a fruit are:

Protect the seeds

In angiosperms, the fruit provides a protective function for the seeds. This is because the fertilized ovules develop internally and the fruit forms around them after fertilization in flowering plants. This is unlike gymnosperm plants which have exposed or ‘naked’ seeds. Some claim that strawberries have their seeds on the outside, but this is not true. The fleshy part we eat is a receptacle, with the actual fruits being the small structures housed on the outside. These are known as achenes and they contain an even smaller seed within them.

Different fruits offer different levels of seed protection. They are normally protected by thick or hardened walls, sometimes providing the seeds with nutrients during its development. Different types of seeds also have different levels of protection, with the pits in stone fruit being notable for their durability.

Providing a physical barrier is not the only way fruits provide protection. Immature fruits are often bitter or unpleasant tasting. Animals may not want to eat them at this point. Only when the fruit matures and the seeds have developed will they become appetizing. It is at this point the seeds can be dispersed once the the fruit is eaten or by falling to the ground.

Facilitate seed dispersal

When the seeds have matured sufficiently, the fruit's protective function changes. It is now important for seed dispersal to take place so that the seeds can germinate and new plants develop. Different types of fruit disperse their seeds in different ways, for example:

• Anemochory: these is a process whereby fruits harness the wind to disperse their seeds. These are very light fruits that shaped in a way that allows the wind to carry them. They may also have hair-like or wing-like structures to aid in this process.
• Zoochory: these fruits develop in such a way that they attract animals to disperse them.
• Epizoochory: a type of zoochory that causes the fruits to latch onto the fur, skin, feathers or other external parts of animals for transportation. They then fall off to the ground somewhere else where their seeds can develop into a new plant.
• Endozoochory: the fruits are ingested by the animal internally. These types of fruit tend to be colorful and fleshy, as well as very pleasant tasting for certain animals. While the fruit is consumed, the seeds are either discarded or excreted by the animal for dispersal.
• Autochory: fruits with the ability to expel their seeds from a distance, as some legumes are able to do.

These dispersal strategies are vital. If the plant were to drop its seeds all around it, it would end up causing intense competition between the original plant and its new offspring. It would also limit the colonization of new territories.

Now we know the functions of fruit in flowering plants, we can look at the parts of a fruit with diagrams. These parts of a fruit encompass two main structures, the seed and the pericarp (see the diagram in the main picture for this article). We look at how they factor in to fruit anatomy below.

You can also discover more about the differences between gymnosperms and angiosperms with our related guide.

The different parts of a flower house the reproductive organs. These are the male and female parts which fertilize each other. The ovules are located in the female part known as the ovary. After fertilization, this ovule develops into the seed.

Each individual fruit may contain one or multiple seeds. This seed is the embryo that will give rise to a new plant if the right conditions are met. It is an indispensable part of the sexual reproduction of flowering plants. The seed of the fruit is made up of:

• Embryo: this is the part of the seed that will grow to become the new plant.
• Endosperm: the layer formed by the reserve substances and nutrients that the embryo needs to grow.
• Integument: this is the outer layers of the ovule which provide a protective function. These compromise the inner tegmen and outer testa parts which eventually develop into the seed coat.

We share a diagram below which depicts the seed after the protective seed coat has developed.

You can learn more about this part of a fruit in plants with our related guide which explains what are seeds, specifically their types and functions.

The pericarp is the part of the fruit that surrounds the seed. Some contain reserve substances, while others do not. It is composed of the epicarp, the mesocarp and the endocarp. We look into more detail at these parts of the fruit pericarp:

• Epicarp: is the outermost layer of the pericarp and consists of what we commonly call the peel or skin of the fruit. The skin of an apple, prickly part of a thistle and shell of a nut are all types of epicarp. They are divided into polychromatic, smooth, granular, pubescent and spiny.
• Mesocarp: is the middle layer which contains the reserve substances. In immature fruits, these substances are citric, tartaric and malic acids, compounds which help the seed develop fully. They also provide an unpleasant taste that makes it unpalatable when immature. Once the seed is ready to be dispersed, the fruit converts its acids into sugars and starches to become highly desirable for consumption. This favors the arrival of animals that will ingest it and disperse the seeds.
• Endocarp: is the innermost part of the fruit and usually consists of a protective layer around the seeds. This is usually harder and sometimes also contains reserve substances.

While we think of them differently in culinary terms, many foods we consider vegetables are actually types of fruit. Learn more with our article looking at the difference between a fruit vs. vegetable.

Below, we show you which parts of the flower become which parts of the fruit in our diagram depicting different stages of apple development:

Fruits differ greatly in many ways, something that affects how they are classified in botany. For example, some classify them according to whether or not they contain reserve substances in the mesocarp. In this way, we can categorize them according to whether they are considered dry or fleshy fruits, as well as numerous subtypes. A more scientific botanical classification divides all fruits into one of the four following categories:

• Simple fruits: those that develop from a single ovary.
• Multiple fruits: fruits that derive from multiple ovaries on the same flower.
• Compound fruits: are also formed by several ovaries, but they eventually unite as they develop.
• Parthenocarpic: also known as sterile fruits, fruits that do not contain seeds, as they form without prior fertilization.

There are also many different fruits when we consider the different types of fruits in terms of how we consume them. We can learn more about one specific type of fruit with our article asking what is considered a berry?

If you want to read similar articles to Parts of a Fruit and Their Functions - With Diagrams, we recommend you visit our Biology category.