Sam (13) asked “What are the building blocks of cells? And does it vary for each cell?”

Up-dated  24/10/2019

Thank you for your question Sam. As usual I put it to a member of my team. Lets see what they say and then, maybe, I can add to it.

Thank you for that team. Cells are obviously very, very important. We, and all, living things are all made up of them. But what about the cells themselves …what are they made of ? A little research shows that all cells contain  proteins, lipids, carbohydrates and nucleic acids. Let’s look at the role of each of these groups of compounds.

Proteins are all important (they are made of things called amino acids BUT enough of that). Proteins have important roles in cells. They provide the cell with energy, they fight infections they help move other components  around the cell.

Lipids are basically fats and therefore are a source of energy. The proteins will access the lipids to help them in their tasks and the Carbohydrates are another source of energy

Nucleic acids are better known as amino acids that make up  RNA and DNA structures. These are probably the most important, ………no I am wrong, the nucleic acid component of the cell needs all the other components to survive. They will not last long if left alone. The nucleic acids are the messengers of the cells. In simple terms they have, in their structure , the message that enables the construction of a living thing (animal, plant) from the activity of the rest of the cell. You could say they are the managers.

A little addition ……. what is an amino acid? Firstly as an acid it contains the -COOH group of atoms. CH3COOH is a familiar acid

Shown here in its structural form

known as acetic acid (vinegar).

Amino acids basically contain NH2 groups instead of CH3 . One of the simplest is glycine.

Proteins also (in some cases) act as catalysts (something that enables a reaction to occur. In these situations they are called enzymes.

I really hope this is helpful. Thanks for the question.

Luisa 9 asks “How did the first humans appear?”

Thank you Luisa for your second question.  Here are my friends thoughts about how humans appeared.

Thanks team, Luisa let me add some more details.

My friends are correct, it is thought that the first life appeared millions of years ago. The life that formed was not at all like the animals and plants that we see around today. It was very, very small. So small that we would have needed a microscope to see it.  Over the next thousands of years that life changed (we say it evolved) and it reproduced. Sometimes when it reproduced mistakes were made and bigger forms of life were formed. Eventually a mistake in the reproduction led to the first plant (a moss) being formed.

Over the next thousands of years further mistakes were made and  the first animal was born. From then onwards the evolution of animals and plants continued…….UNTIL …..again many thousands of years ago the first apes evolved. The apes continued to have babies and further mistakes were made …… the baby apes walked upright, their brains were bigger, they had less hair, all small changes but over thousands of years small changes can become big changes. The result was that humans were formed and you, me and everybody else are the result.

Things haven’t stopped ….changes (evolution) continues …..we might be very different in many thousands of years time.

Hope this helps. Not happy about something, then ask another question.

“What does “eco” in ecosystem mean?” asks Austin (8)

I will just add a few words myself. Thanks for your input.

I like the idea of an ant’s nest being an example of an ecosystem. The nest is ‘everything’ it’s a home, a place to live and to work from, a creche for baby ants, a food store, a food production place, a protective environment, maybe an ant hospital, and lot’s more. It is an ecosystem.

The word ‘eco’ also combines with ‘logy to form ‘ecology’. This is like the word ‘bio’ combining with ‘logy’ to form ‘biology’.  The word ‘logy’ is a word which originally described lots of learning.

I will stop now. For an eight year old I think everything gets very complicated. I very much like the ant’s nest described as an ecosystem.Maybe you could let me know of other ecosystems?

STOP

“Did humans evolve from monkeys?!?!” asks Destiny (10)

A great question Destiny and a difficult one to answer. You use the word ‘evolve’ in your question. I think we should spend the first part of a possible answer looking at that word – ‘evolve’. I thought I would ask my friends about this. Let’s see what they come up with ….

It was Darwin, a famous scientist, who proposed that all living things over time are slowly evolving. So another thing we have to think about is time. 

Life on our planet is thought to have been created four and a half billion years ago. That is 4,500,000,000 years ago. That give a lot of time for something to happen (evolve)  gradually.

Scientist think that ALL living things on our planet started 4.0 billion years ago with the formation of the first micro-organism that could reproduce itself. It was no bigger than a pinhead.

Below is a crude timeline which illustrates  how different life forms evolved (developed) over those millions and millions of years from that pinhead.


So Destiny, we have evolved from the primates but the primates evolved from other living things, and it started 4.0 billion years ago from that pinhead

I think the crucial factor in understanding this in the time span …which is unbelievable to us who live for such a short part of the story.

Unhappy about this, then please write a comment or ask another question.

(rewritten June 5th 2018 )

Chris (10) asks “How can you correctly determine the age of a tortoise or turtle?”

Chris thank you for your question. Some people suggest that it is the number of scutes (the bony rings that the tortoise has on its shell. However look at this baby tortoise breaking out of it’s shell.

Here he/she is and already there is more than one scute. Maybe we need to take a hint from a tree. How do you find the age of a tree. When you cut a tree down you can see inside of the bark a series of rings. (You can obviously do this without chopping the tree down).  Look at the image below.

The scutes of a tortoise also have rings. The image below is an ‘old’ tortoise.

This image is of a very young tortoise

Maybe these will give you a clue about the tortoises age. It is thought that this could be a rough age indicator.

Alternatively you could get a size chart, however, like the rings it is difficult to accurately determine the age of a tortoise. Maybe the only true way is to know when it was born.

Will (8) asks “What makes seeds grow?”

 

Will, thank you for your question. Let’s start with some interesting questions. Answers to these might help in answering your question. Firstly is a fruit a seed?  If it is not a seed then what is it for? Does it help the seed grow? How will we know if the seed is growing? What does a seed need to grow? Does it need soil? Do seeds grow when it is cold? Do different seeds grow at different speeds? What do you think? Are there any more questions? Remember questions are what science is all about. By investigating questions you are building knowledge of the world around you.

So, let’s think about how we could investigate some of these questions. Shall we look at just one type of seed, or choose a variety of different seeds to investigate? Maybe looking at one type of seed would help us begin to answer some of the questions. We could then look at another type of seed and compare the results. Maybe one seed would grow faster than the other?

Now we have to think about the conditions for our growing experiment ….. soil/no soil, wet/dry, light/no light, hot/cold. Even for our selected seed this can be very complicated. Can you see why?

The investigation equipment could probably be obtained at home. A empty plastic bottle, with the top cut off, would be a good holder for the seed. Some cotton wool could act as soil. A cupboard and a refrigerator could also help you create the right environment.

Let me know how it went?

“How many living things are on Earth?” asks Kaia (8)

Thanks team.

If you want a definition of ‘living’please click on the link.

The species  butterfly has  20,000 of the 1 million species in the insect group. At any one time there must be thousands of living Cabbage White butterflies flying around so you have 20,000 different types of butterfly flying around and maybe there are 50,000 of each type living at any one time.  Help. I must admit the calculations are frightening so i cheated and looked at the work of other scientists who say that there are  8 million species and each species has millions of living specimens. 

The homo species (us) has 9 billion living specimens, I suspect the ant population is considerably bigger than that so in answer to your question …. and then think of the number of plants  ….and then the number of bacteria …..there is no believable answer. However somebody has tried and they had difficulty putting all the numbers on their sheet of paper. Sorry Kaia.

If there are other questions which you may have thought of then please fill in the Reply box below or ask another question.  

Revised 17/102017  Numbers on image changed and text rewritten.

Laura G (10) asked “Is it possible to collect condensation to water a garden?”

Laura, have you ever on a warm day noticed faint water droppings on leaves of some of your plants. Where has this water come from? It might have come from the leaf itself or alternatively it might have come from the atmosphere. The atmosphere/air around us can hold an immense amount of water in its vapour form. For example a parcel of 1 cubic meter of air at 30 degrees centigrade could contain 28g ( or 28 cc) of water. There is therefore a good chance that those drips on the leaf came from the atmosphere.

The fog fence provides a surface that is colder* than the air around it and therefore a place where water vapour can condense and the water collected. The water can then be used for irrigation of plant life AND the plant life itself generates it’s own water vapour so it is possible to use a fog fence , in a desert like area to collect water, feed it to plants and begin the process of creating a self sustaining green environment.

I am happy for suggested revisions to the above arguments.

*Sorry Laura,I have given you a completely wrong bit of information. It is very unlikely that the fence would be at a different temperature from the air around us. So how does it aid condensation?  It’s made of metal. What do you feel when you touch a metal object that has been lying around on your table?.

See a previous question that may give you a clue.

It feels cold. Why? It should be at the same temperature as the rest of the objects on the table. It feels cold because metal is a good conductor of heat and as your fingers are quite warm it conducts the heat away from them and they feel cold. Maybe the metal in the fence is conducting heat away from the water vapour and because it loses heat it changes from the vapour form to the liquid form …..condensation.

Para added 15/10/17

link added  15/01/18

Mary Ann (10) asks “Why are most leaves on trees green?”

Mary Ann. I sometimes think it is amazing that  leaves are so successful because they reflect green light ….the don’t want it.

Remember that white light from the Sun is a mixture of all different colours.Below you can see the result of white light being passed through a prism. the chlorophyll in leaf absorbs the deep blue and the red light and reflects the green light.

For red leaves the chlorophyll is hiding in the colour of the leaf. Our eyes cannot see it.
If you want to know a little bit more then ask another question.

(Anyone reading this post who wants to ask a question or make a comment please feel free to do so)

Lara (12) asked “Do plants have brains or nervous systems?”

Great question Lara.  No, plants do not have brains or a nervous system BUT they may have something similar.

The brain and the nervous system are defined by science as consisting of special cells called neurons which pass messages to the brain and the neurons in the brain then process these messages. Plants do not have neurons in their structure. So if a plant can feel, communicate and maybe solve problems it is achieved by something other than the brain.

Lots of scientists have/are looking at plants and their behaviours. There is good evidence that plants can communicate with each other, trees (and maybe other plants) even have their own internet. Not a conventional network but an internet of fungi. It has been discovered that the fungi ‘roots’ called mycelium (they are not really roots …they are the main part of the fungi, the thing we see is just the ‘fruit’) create a network of filaments in the soil stretching great distances and connect to other plants around them. Researchers  have found that trees communicate information on food, insects and other dangers to each other using this network..

Mycelium

There is a lot we do not know about plants.

A question. Suppose you had access to ten trees and a mycelium network. What experiment would you setup to test the ideas about the trees communicating  and helping each other.

Hope this helped. Need further help then please ask another question or make a comment.

Science Master

(Anyone reading this post who wants to ask a question or make a comment please feel free to do so)

Revised 9/9/17 Added  ‘A question.’ Last para.