Thursday, 15 February 2024

 Many cnidarian species use alternation of generations to reproduce. In other words, one generation reproduces asexually (the polyps), ususllya by fragmentaion or budding and the next generation reproduces sexually ( the jellyfish). In that way these animals benefit from both types of reproduction


You can read a lot more about jellyfish by clicking on the following link:

https://ocean.si.edu/ocean-life/invertebrates/jellyfish-and-comb-jellies#section_16508

You can also check out the following video:


ACTIVITY - NOMENCLATURE

Watch the video carefully and make a list of all the specific names that come up.



Thursday, 13 October 2022

HYBRIDS - THEIR ROLE IN EVOLUTION

 During the class about taxonomy and binomial nomenclature we introduced the definition of species. Many of you brought up the subject of hybrids and questioned if they were considered species or not. Most hybrids are not fertile descendants,so in this case, neither  their progenitors are considered members of the same species nor are they accepted as new species. Nevertheless cross reproduction and the appearance of hybrids is one of the fastest ways of creating new species on the planet and therefore play a vital role in evolution. It has always been known to be frequent in plants. These are considerd new species if they are fertile, reproduce and begin to conquer and adapt to their ecosystem.

 After talking about this in class I came across this national geographic article which I think may be of your interest. Click on the following link to read about this interesting topic!

National Geographic Ligers, zorses, and pizzlies: How animals hybrids happen

Monday, 3 October 2022

REAL IMAGES OF REAL CELLS!!

 What we see with the microscope is usually very different to the picures of cells in books.

If we look at a prokaryotic cell under an electron microscope we will see an image quite different to the picture in our science book. At first we may think that it doesn't correspond at all to what we have studied. After some time and if we look at it in detail, eventually we will probably be able to identify the different parts, like the genetic material dispersed in the cytoplasm and even the ribosomes. Look at this picture.


Now clik on this link to see an interesting presentation about prokaryotic cells: 

Tuesday, 27 September 2022

THE CELL THEORY

 In class we are studying what living things are made up of. We have seen that the main atoms that constitute living beings are carbon, oxygen, hydrogen and nitrogen. We have also seen that the  atoms join together to make the molecules of the substances of living beings. Some of these molecules are inorganic and others organic . 


Molecules join together to form cells, which are the basic structural and functional unit of life. Cells are microscopic and have not been able to be studied until the microscope was invented. Over the years, different scientists discovered different things about cells and established the cell theory in the 19th century.


 In this article you can read about what the cell theory states and what scientists developed it. Click on this link.

THE CELL THEORY -NATIONAL GEOGRAPHIC

You can also watch and enjoy the following video!