Time flies… It’s the last lesson together with Dr. Parameswari, a very dedicated and well-experienced lecturer I could say. Today we were having a quite relaxing lesson, we discussed the question papers and did our last quiz on plant growth regulators. First of all, I would like to show my gratitude to her for being a responsible lecturer. 

Her lecture was not boring at all except for the video she asked us to watch. In the first lesson, she mentioned that she was not going to spoon-feed us like what the teachers did in high school.

So, since then, I have to be more independent and take initiative to search extra information such as books, video and animations to help me understand better. Some topics like endosymbiosis, totipotency and callogenesis are totally new to me. So I have to put more effort and time on that particular topics. Anyway, I am looking forwards to meeting her in the next semester.

Today, once again we were having quiz in the computer room. I was quite shocked because I haven’t revised anything although she had informed us earlier that we would be having a quiz. 

Okay, fine. I used my phone to access to putrablast since all the computers were fully occupied. We did two quizzes which were cell division cycle matching quiz and and quiz on plant sexual reproduction. Luckily I still managed to score the quizzes.

Later, we did our group activity by drawing the venn diagram on the similarities and differences between sexual reproduction and asexual reproduction of plants. After this, we did another venn diagram on the similarities and differences between self pollination and cross pollination. In the following lesson, the lecturer continued on topic 7 which is the regulation of developmental and differentiation hormones. We were introduced to 5 major types of hormones which are auxins, cytokinins, gibberellins, abscisic acid and ethylene. The lecturer explained the functions of each hormone in detail by giving examples and drawing of plants.

 

Also, the auxins and cytokinins show antagonistic pairs where auxins suppress the growth of lateral bud but cytokinins promote cell division and shoot formation in plants. Abscisic acid often serves as an antagonist to the action of gibberellins and auxin.  Gibberellins induce flowering and work with auxins to promote elongation and division of stem tissues while abscisic acid promotes dormancy and inhibits shoot growth. Ethylene which helps in fruit ripening is the only hormone that is in the form of gas at room temperature. What I feel amazing was that auxin promotes parthenocarpy, which is the development of unfertilized ovary into fruit. Hence, the fruits produced are seedless since sexual reproduction does not occur. How fantastic it would be to enjoy the seedless fruits!

Hello! Today we just submitted our first assignment, cartoon on natural selection. I think my group has done a great job because each of us was putting our full effort and contribution to this assignment. Dr. continued her lecture of cell division and what I feel interesting was totipotency. A plant cell, tissue or organ can be regenerated into a whole new plant under right condition. Wow! How amazing it could be!

 

And I think the part that most of us had difficulty to understand was callogenesis. However, Dr. was explaining slowly to us about the forms of plant changing throughout the process, from undifferentiated tissue to differentiated tissue. I was really paying full attention to this part so that I was not confused by dedifferentiation and redifferentiation.

In the next lesson, we learned about pollination and development of plant embryo. It was almost the same as what I learned in the past and I am quite familiar with the terms “pollination”, “double fertilization” and “embryogenesis”  but I have to take my time to recall all these processes and the reproductive organ of plants.

Things that was new to me was somatic embryogenesis. Dr. was explaining that part in detail to make sure we fully understood and not confused. Today, I am introduced to even more new terms such as differentiated  and undifferentatied cells, callus, direct and indirect organogenesis but all these terms can be easily absorbed and digested after the clear explanation by Dr. Parames. We drew the venn diagram to illustrate the similarities and differences between zygotic and somatic embryogenesis as usual.

Wow! It’s almost a month together with Dr. Parameswari. Well, today we learned about endosymbiotic which I never heard before. But, it’s okay. I hope I could understand after attending the class. This topic is basically used to describe the origin of mitochondria and chloroplast. Where did they come from???

Mitochondria and chloroplast are at one time free living cells, they are able to survive on their own because they have their own ribosomes and DNA which enable them to replicate themselves.

As usual, each group drew a venn diagram to illustrate the similarities and differences between mitochondria and chloroplast. In the next lesson, we are asked to shift to the computer room to access the quiz on cell. OMG! It was totally a shock to us since we didn’t prepare ourselves. 

Later, we continued our class on cell division. The cell cycle of eukaryotes consists of interphase (G1, S, G2 phase) and M phase ( prophase, metaphase, anaphase and telophase).

It was totally same as what I learned before so I think I can handle this topic well and didn’t really focus much on it. However, I was a bit confused when it comes to the regulation of the cell cycle which is controlled by the proteins in the cytoplasm called cyclins because every phase involves different cyclins!! Maybe I just shouldn’t be overconfident…

It’s the third week of lecture. Today, it was all about cell theory and prokaryotes. We were introduced to 3 cell theories of life:

- All living things are made up of cells.
- The cell is the basic unit of life in all living things.
- New cells arise from the pre-existing cells.

However, modern cell theory has additional 4 statements which are:

- the cell contains hereditary information (DNA) which is passed on from cell to cell during cell division.
-all cells are basically the same in chemical composition and metabolic activities.
- all basic chemical and physiological functions are carried out inside the cells including movement, digestion and homeostasis
-cell activities depends on the activities of subcellular structures within the cell which are the organelles, nucleus and plasma membrane.

Later, Dr. Parames introduced 2 types of cells which are prokaryote and eukaryote. At first, I thought that prokaryotic cell is pretty easy to me because it is just a unicellular organism without membrane bounded organelles. However, when I studied a bit more detail, I found that actually it was not as simple as it looks. Previously, I only knew that cell wall is always composed of cellulose but in fact that is just for plants, while the bacterial cell wall is composed of peptidoglycan.

Besides, the gram-positive bacteria and gram-negative bacteria are new to me as well where the gram-positive bacteria absorb and retain crystal violet stain due to its thick cell wall while gram-negative bacteria appear red because of the thin cell wall and thick outer membrane.
 

Later, we sat in our own group and make a venn diagram on the similarities and differences between archaebacteria and eubacteria. I think that was such as effective way of teaching because through the venn diagram we could see the similarities and differences clearly. In addition, that venn diagram can be part of our notes as well. So why don’t we do this often? In the next lesson, we discussed about viruses, viroids and prion.

It’s second week of lecture. Today, we started the class by discussing the worksheet on “Darwin Observations” and “Evidence for Evolution”. Through these exercises, I understand that common ancestry among the species can be come from sources like fossils, biogeography, embryology and anatomy. 

In Darwin’s theory, he stated that all the species have evolved over time from common ancestors through the process called natural selection. Natural selection is a process whereby organisms that are better adapted to the environment tend to survive and produce more offspring. Natural selection happens because of the change in genetic material but not physical traits. And there are 4 principles of natural selection which are variation, overproduction, adaptation and descent with modification.

Later, we were asked to form a group of 4-5 people and started our group activities. Our first group task given by Dr. was choosing the fittest crab among sharpy crab, big spotty and little crabbie. Most of the groups chose little crabbie because it produces large amount of offspring and have better adaptation to the environment.  Actually there was neither right nor wrong in this section, Dr. just wanted to ensure that each of us understand the concept of evolution and natural selection through this interesting activity. After that, we proceeded to the next topic which was history of life. I had difficulty understanding this topic because I don’t like history and I never learn this topic before. 

What I learned in the lesson was the origin of life occurs through chemical evolution and biological evolution. The earth was formed about 4.6 billion years ago and the first life began at 3.8 billion years ago. The first cell began from small organic molecules bonding together to form macromolecules, and packaging macromolecules into protobionts which are able to replicate itself. Prebiotic broth hypothesis explains the chemical evolution occurred on the earth.  This topic is quite long but I will take my time to understand it because history of life is very important, at least we have to know how is life formed and what is our ancestor. The following part of this topic is systematic, taxonomy and classification. I feel much easier learning this topic because previously I have learned about it. Archaebacteria and eubacteria are something I have never learned before.

Their characteristics are almost opposed to each other where cell wall of archaebacteria doesn’t have peptidoglycan while cell wall of eubacteria has peptidoglycan. Phylogenetic tree is new to me as well but I found that it is quite interesting because from the branches I know that whether the species are from the same ancestor.

Hello! This is my very first lesson of Cellular and Developmental Biology with Dr. Parameswari but I was late for my first class. Luckily there was no punishment …In the first class, Dr. was telling her “Rules and Regulations” to us. She emphasized that we should not help others to sign for attendance or else we will get into BIG trouble.Besides, we should also read through the lecture notes and do the given exercises before the following class. Okay, I am a bit tensed right now.

The first lecture was about introduction to evolution and Charles Darwin, Father of Evolution. 

In this topic, we will learn about Lamarck’s theory and Darwin’s theory. Lamarck thought that environment pressure causes body changes. If an organism changes during life in order to adapt to its environment, those changes are passed on to its offspring. He said that change is made by what the organisms want or need. 

Giraffes are used as an example in the lecture notes where giraffes evolved their long necks by each generation stretching the necks further to get leaves in trees and that changed the body shapes of giraffes and was inherited. It doesn’t sound logic…On the other hand, Darwin’s theory stated that all species of organisms arise and develop through the natural selection to increase the ability of an individual to compete, survive, and reproduce. Charles Darwin was influenced by the book entiltled “Principles of Geology” documented by Charles Lyell and Lyell’s idea led Darwin to his understanding of biological evolution. What I understand from this lesson was that, each of our characteristics is carried by genes which enable the characteristics to be passed on to the next generation. Evolution will occur over time through natural selection and dominant traits will be passed on and shown in the following generation. Soon, the organisms that carry the recessive trait will slowly extinct due to their low adaptability and ability to compete with others. Before the lesson ended, Dr. asked us to watch a lecture on “ Endless Forms Most Beautiful”. It was a quite boring and super long video and I was desperated while watching this almost one hour video due to the slow internet connection. 

From the video, it would help to complete our activity on “Darwin Observations” and “Evidence for Evolution”. However in the next lesson, most of us hadn’t watched the video due to internet problem so we can’t discuss the worksheets. And she gave us the second video on “Natural Selection vs Artifilcial Selection” which is almost the same length as the previous one…