Have you ever stopped to wonder how plants and humans reproduce? It’s a fascinating process that’s essential for the continuation of life. As we all know, humans give birth to babies, while most flowering plants grow from seeds. But have you ever stopped to think about the similarities and differences between reproduction in plants and humans? What are unique physical structures involved, and how is reproduction carried out?
In this article, we will explore the fascinating world of plant and human reproduction. By looking at the remarkable mechanisms and adaptations that enable these diverse organisms to reproduce successfully, we will delve into the science behind these fundamental biological processes. Get ready to gain a deeper understanding of the amazing diversity and complexity of life on our planet.
An Overview: Reproduction in Plants
Image via @Let’s Talk Science
Unlike humans which give birth to babies, plants reproduce either sexually or asexually. Asexual reproduction only requires one plant to make a replica of itself, such as the reproduction of fungi and daffodil bulbs. Similar to other species, sexual reproduction in plants (the focus of this info page) requires both female and male gametes in order to make a new plant.
In this article, we will only explore sexual reproduction which involves the transfer of the male reproductive part (pollen) onto the female reproductive part (ovules).
Components Involved in Plant Reproduction that every Primary Science student should know
Plant Reproduction – Pollination & Fertilisation
For fertilization to occur, pollen has to be transferred from the male anther to the female stigma of a flower: a process known as pollination.
Wind pollinated flowers:
- They have feathery stigma that hangs outside the flower. This increase the surface area to trap pollen grains in the wind easily.
- Anther hanging out of flower to release pollen grains easily.
Small petals that are dull (no need to attract insects).
- No nectar and no scent (no need to attract insects).
- Light and small pollen grains to be easily carried by the wind.
Animal pollinated flowers:
- Sticky stigma inside the flower to brush against pollinators like animals and insects.
- Anther within the flower to brush against pollinators easily.
- Large petals that are colourful to attract pollinators.
- Has nectar and is sweet smelling to attract pollinators.
- Sticky pollen grains to stick to pollinators well.
Extra notes on fertilization:
- Self pollination: transfer of pollen grains to stigma within the same flower/ plant.
- Cross pollination: transfer of pollen grains to stigma across different flowers of the same species
To ensure successful reproduction, pollination is necessary for plants. After pollination, the pollen grains on the stigma starts growing pollen tubes down the style. These tubes help male reproductive cells within the pollen grain to travel down to the ovules. Once the male and female reproductive cells fuse inside the ovule, fertilisation takes place. After fertilisation, the ovary develops into a fruit and the ovules develop into seeds.
Note: Even if a flower has undergone pollination, it does not necessarily mean that it fertilisation will occur.
An Overview: Reproduction in Humans
The female reproductive system releases an egg cell from the ovary, which travels through the fallopian tube. Sperm enters the vagina and swims up to fertilize the egg cell. The fertilized egg cell, or zygote, develops into an embryo and eventually a fetus during a gestation period of around 9 months. Throughout this period, the fetus receives nutrients and oxygen from the mother’s blood through the umbilical cord, while waste materials and carbon dioxide are transported back to the mother’s blood.
What are the similarities between reproduction in plants and humans?
- Both the plant and human reproductive system have male and female reproductive cells. In humans, the female reproductive cells are called egg cells and the male reproductive cells are called sperm cells. As for plants, the female reproductive cells are found inside the ovules and the male reproductive cells are found inside the pollen grains.
- Both the plant and human reproductive system require the female reproductive cell to be fertilised by the male reproductive cell for the young/ offspring to start developing.
- Fertilisation is essential for the offspring to start developing in both systems. This process involves the fusion of male and female reproductive cells.
- The ovary in a flower is similar to the ovaries in the female human reproductive system, as both contain the female reproductive cells.
- The anther of a flower is similar to the testes of the male human reproductive system, as both produce the male reproductive cells.
- Lastly, the stigma of flowers is similar to the vagina in the human female reproductive system, as both receive the male reproductive cells.
How different are the reproduction in plants and humans?
- For plants to reproduce, they will need to go through pollination. This process requires pollinators, such as bees, or wind for the fertilisation to take place successfully. On the other hand, humans do not undergo pollination.
- Some plants can go through self-pollination and fertilisation, while humans cannot fertilise themselves without another human’s reproductive cells.
- After fertilisation: In plants, the ovary develops into a fruit and the ovules develop into seeds. The number of seeds depends on the number of ovules. In humans, the fertilised zygote develops into a fetus.