The process of germination and plant growth

Have you ever wondered what do plants need to grow or maybe what process should the plant go through before it grows. Well, it all begins from seeds. 

Many plants reproduce from seeds. The development of seeds into a young plant is called germination. Seed germination will only take place when conditions are right. In this case, the seed requires a sufficient amount of water, warmth and air to start to develop. 

Six stages of germination:

1. Once the seed gets enough water, it will absorb the water then swell, causing its coat breaks out. 
2. Then the first root will grow downwards through the broken coat. 
3. The stem grows upwards.
4. More roots grow downwards.
5. The stem grows taller and the shoot appears above the ground.
6. Finally, it becomes a seedling where its leave can do photosynthesis (to produce food). 

From the six stages of germination above, you can understand clearly that during the process of germination, the presence of light is not required for the seed to start growing. This is because the seed does not have any leaves yet to produce its food (photosynthesis). So where does the energy come from?

Parts of a seed

Well, there are three main parts in a seed. The baby plant or embryo that can germinate into seedling when conditions are right. The seed leaves that store food, this is where the seed gets its energy from during the process of germination. Also, the seed coat that protects the seed. 

So, the seed does not need light to germinate as it has stored food in its seed leaves to supply energy during the process of germination”

Read Also : The life process 

You can prove this theory by experimenting. To ensure the test is fair, you have to be certain that you only change one variable that you investigate and keep other variables the same. You may watch the following video to help you.

To find out whether your experiment result is reliable. You can repeat your experiment. If you obtain similar or slightly different results, meaning its reliable. However, if you obtain very different results, meaning its unreliable. 

Hint :

1. Variable is a factor or a condition in an experiment.
2. Variable to change is a variable to investigate in an experiment.
3. Variables to keep the same are the variables to ensure the test is fair. 
4. Reliable result means can be generalised.

By the time the seeds have developed into seedlings or young plants, the stored food as the source of its energy has been used up. In this regard, the young plants must be able to produce its food. The process of food making in plants is called photosynthesis which involves the presence of light, enough amount of water, warmth and air. This explains to us that plants can only grow healthy when those four-mentioned factors are fulfilled. 

Similar to germination, you also can prove either light is needed for the plant to grow or not. Simply take two identical seedlings, give them the same amount of water, then place one of them in a warm dark room and the other one in a warm bright room. You can observe daily how both plants grow. After 10 days, you will notice that the seedling from the dark-room is dying as it does not get enough sunlight while the plant in the bright room will grow healthy as all four factors are obtained.

In the process of experiment, you can use some apparatus such as :

• Ruler to measure the length/height of the plant in the unit cm.
• Measuring cylinder to measure the volume of water in the uni ml/cm³ (read: centimetre cubic)
• Thermometer to measure the temperature of the surrounding in the unit ℃
• Table to record your experiment result. Also, the bar chart/line graph to plot your data. 

In short, germination can take place without light while plant growth cannot. 

Seeds need enough water, warmth and air to germinate. While, plants need enough light, water, warmth and air to grow”

Factors needed for Germination VS Plant growth

So that’s about germination and plant growth. Now, let's try this!

lily wants to find out whether a plant can grow in artificial light instead of sunlight. 

1. Write down the aim of her investigation
2. The materials she will need
3. The variables she will change and keep the same

Write your complete answers in the comment box below! Be sure to use your name before submitting it!

Your loyal Cap. Idaa 

Adios Amigos

Learn other science topics here: 

The water cycle

The solar system

Hi kids, congratulations you made it to the end of biology chapter  in this semester.  As you notice that this chapter focuses on living things, how they adapt, how they eat, how they reproduce and even how they connect each other (between plants, animals and human beings). Plenty of topics have been explained to you in biology chapter started from life processes until how human can stay healthy. So, in this article I am going to highlight what have you learnt about biology.

Begins with life processes, a process that keeps living things (animals, plants and human beings) alive, that include nutrition, movement, growth, reproduction, respiration, sensitivity and excretion. As living things grow, their sensitivity makes them aware of their surroundings because of their senses. There are five senses attached on them - sight, hearing, smell, taste and touch which are all detected through different sense organs such as eyes, ears, nose, tongue and skin. 

Living things can be sorted based on their distinctive features, helping them adapt well in their habitat (a place where plants and animals live). The organisms that live in a habitat are adapted to live in the habitat. Owing to this fact, scientists can easily classify them by looking at how they are similar to and different from each other. The sorting of living things into groups is called classification.

Plants, on the other hand, have four main parts such as roots, stem, leaves and flowers. It starts its life cycle from germination when conditions are right which means the seed can only germinate when it gets enough water, warmth and air. Once it becomes seedlings, a sufficient amount of water, light, warmth and air, is required for them to grow healthy. A fully-grown plant will produce flowers that contain the reproductive organs of the plant (both female and male) which make and receive pollen.

The male parts, known as stamen, consist of the anther, which produces pollen, and filament, which is a stalk that supports the anther. Meanwhile, female parts (known as pistil or carpel) consist of stigma, style and ovary, which contains ovule. 

The transferring of pollen from the anther to the stigma is called pollination (can either be done by wind or insects). Each pollen grain then grows a tube down to the ovule in a process known as fertilisation, resulting in the ovary becomes a fruit and the ovule becomes seed (seed production). Finally, the grown-fruit disperse its seeds by animals, water, wind or explosion (seed dispersal) - and the cycle starts again.

However, in what ways the plants help the animals?🤔

Well, it's simple, the animals cannot make their food so must obtain it from plants or other animals - this is what we called a food chain. So, the plants provide food for the animals and when animals die, they will become decomposer which provides minerals for the plants. wow, amazing right?

Nevertheless, this chain does not go as it supposed to be due to the careless of human activities such as cutting down trees to build up power station that causes organisms lost their habitats and pollute the atmosphere with greenhouse gases, even worst resulting some species go extinct. For these reasons, the human must apply 3R’s (recycle, reuse and reduce) to keep the life balance on Earth. 

Kids in a choir

Flicking a ruler

Accordingly, can human produce sound? 

We, humans, have a vocal cord inside our larynx. This cords will vibrate when we speak or scream, resulting in us to produce sound. Imagine, if this cords stop vibrating, no matter how hard we scream we still don't make a sound.  

When you whisper someone, your vocal cords will have small vibration, producing soft sounds. Conversely, when you scream, large vibration produces loud sounds. These sound levels can be measured using the sound level meter in the unit decibel (dB). Normally, a human can hear up to 140 dB, above this number can result in permanent hearing loss. Wearing ear defenders and closing doors and windows can help us protect our hearing. 

How do sounds travel?

Sounds can travel in three different matters like solids, liquids and gases. 

How sounds travel in three different matters

The picture above shows how sounds can pass through solid, liquid and gas. We can hear different sounds in anywhere we are due to these matters are all around us. 

Sounds can be bent and absorbed depending on the type of the materials. Hard materials such as wall, stone and wood can bend sound. Soft materials such as carpets and sponges can absorb sound.

To understand more about sounds, you may watch this video:

• Hairdryer blowing = …… dB
• Human breathing = ……..dB
• Aeroplane taking off = ……….dB
• Background music playing = ……….dB
• Siren sounding = ……….. dB