In this week which
is maybe the last week for Dr. Parameswari give us her lecture on this course
subject, she tought us about Plant Hormones. Plant hormones are chemicals
produced by plants that alter growth patterns and/or maintenance of the plant
as well as promote cellular activities. Plant hormones are also divided into
two type which is endogenous and exogenous. Endogenous is a substance produced
by a plant that affects the pattern of growth and development where the production
by the plant is regulated by the environment. Exogenous is a substance applied
to the plant that alters growth and development in the same way that endogenous
substances do. More over, there were hormone classes which is include
auxin,cytokinins,gibberellins,abscisic acid and ethylene. That is what I have
Dr. Parames tought us and she will be finished it soon.
Apart
from this week, Dr. Parames take a minutes to discuss about the Test 1 that we’ve
already did. This is for now and overall, I have a best lecture in this BSM3101
class. I will strive for this course subject.
Weekly Reflctions - Week 6
On this week I’ve learned many things including cell cycle, totipotency, pollination and embryo development. This is all about plant. At the same time, I have to understand all of this topics to prepare for my exam especially. Basically all living things undergo cell division and growth. They divide and grow to replace lost or damaged cells, to allow an organism to grow and also to reproduce the next generation. Basically in prokaryotes the cell cycle is simple and may occur as often as 20 minutes but in eukaryotes the cells that divide regularly will go through the cell cycle in about 24 hours. So talk about eukaryotes, its cell cycle consist of four different phase that is GAP1(G1), Synthesis phasa(S), GAP2(G2) and Mitotic phasa(M). In the mitosis cycle phase, it consist of prophase,metaphase, anaphase, telophase and last but not least cytokinesis. The passage of a cell through the cell cycle is controlled by proteins in the cytoplasm called Cyclins. Each phase has different controlled protein. Next, I learned about plant growth and meristematic tissue in the plant where lecture had told us how it can growth and which one is the meristematic tissue is. Other that, I’ve learned about totipotency which the new topic and it’s really new in me since I study in a science stream. So, totipotency is the ability of a individual plant cell or plant tissue or plant organ to regenerate into a whole plant under right condition. At the time we learning about totipotency, Dr. Parameswari brought along a sample of plant tissue culture from someone ‘s else project. It is not really new for me to take a look of that plant tissue culture because I’ve been doing plant tissue culture before this from another university and it was really awesome and I would like to do it again. There are four sample that Dr. Parames brought to the class which is a plant that grow more to stems and the other more to roots. This is because of the agar produced that has different hormones added wether it is high in auxin or high in cytokenin. In tissue culture, we have been showed how plants undergo from explant to embryo, explant to callus, callus to plant organ or from explant directly to plant organ. Which is roots or stems.
Next, I learned about pollination and development of plant embryo. Pollination is one kind of familiar topic because I already learned about this since in primary school. But I like this topic because it shows on how does plant develop where there are agents for pollination such as insects and winds. Insect pollination typically involves flowering plants and wind pollination involves non-flowering plants such as grass, conifers and many more. After the pollen has been transferred to another plant, the pollen will undergo zygotic embryogenesis. To form zygotic embryogenesis, there is plant cycle occurs. Not only that, the is also life cycle of angispearm which is flowering plant. In pollination also occur double fertilization in the ovules and which also produced endospearm. While listening to the lecture, Dr. Parames gave us an exercises through the slide. It was really helpful for us to reminds and remember all that stuff we have been learned before.
Weekly Reflections - Week 5
As usual, Dr. Parameswari came and gave us her fifth week lectures and it is all about endosymbiotic theory. I’m very excited to heard and watched Dr. Parameswari lectures time because the way her teach didn’t make us boring and it was totally awesome. So, this week I’va been tought the theory of endosymbiosis where it’s basically stated that mitochondria and chloroplast are originally from prokaryotes but in general, they are considered to have originated fron proteobacteria through endosymbiosis. American biologist, Lynn Margulis said that some organelles within cells were at one time free living cells. She also stated that organelles with their own DNA that is chloropast and mitochondria. Endosymbiosis theory have suggest that eukaryotes arose from a symbiotic relationship between various prokaryotes. Heterotropic(aerobic) bacteria became mitochondria and cynobacteria(photosynthetic) became chloroplast. Last but not least, host cell was a large eukaryotic cell. Research have found that there are similar characteristic that proves that mitochondria and chloroplast is from prokaryotes. This really did makes me shocked because from the first i tought that both mitochondria and chloroplast is from eukaryotic cells. Dr. also gave us a SCL activity of group on giving out the differences and similarities of mitochondria and chloroplast. Not only that, she also gave an exercises of group on determine what mitochondria and chloroplast are. Is it from prokaryotes or eukaryotes and we’ve identified that both two cells are originated from prokaryotic cells. The ideas on how these two organelles can join the eukaryotics cells is; eukaryotic cells undergo phagocytosis and basically engulfing food and by accident mitochondria and chloroplast were swept along into the eukaryotic cells. So as time pass by, mitochondria and chloroplast get into eukaryotic cells and permanently stay in eukaryotes.
Weekly Reflections - Week 4
I directly go for the week 4 reflections because this is my first class because I’m a second intake students. So this would be my first reflection of this course subject that is Cellular and Developmental Biology. So, what was I study in this week ? Of course it’s about Cell Theory about prokaryotic and eukaryotic cell and also virus along with their characteristics. What is remarkable about this week topic is that the cells itself where a bunch of scientists were tried to discover the origin and theory about that cells. Scientist that involved in the discovery of cell is Robert Hooke, Anton van Leeuwenhoek, Matthias Jakob Schleiden, Theodore Schwann and last but not least is Rudolph Carl Virchow. All this scientists worked hard to discover and study about cells and as a results they come out with different kinds of theories. So, is cell living cells or not? That is some of an exceptions to cell theory were discovered by the scientists. They found that mitochondria and chloroplast is a subcellular organelles which carry info and replicate independently but differ with multinucleated single cell such as muscle cells and fungal hyphae. Suddenly earth evolved and introduced modern cell theory which has additional of 4 statement. The first is the cell contains hereditery information which is passed on from cell to cell during cell division. Secondly, all cells are basically the same in chemical composition and metabolic activities. Thirdly, all basic chemical and physiological functions are carried out inside the cells such as movement, digestion, homeostasis and else. Last but not least, cell activities depends on the activities of subcellular structures within the cell such as organelle, nucleus and plasma membrane. At the same time, I found that there are two basic types of cells that is Prokaryote and Eukaryote cell where both of this cells are living things. Prokaryotic cells were divided into two domain that is Eubacteria and the other one is Archaeabacteria. On a eukaryotic cells only has one domian that is Eucarya. More than that, I’ve identified that prokaryotic cell structure and it’s functions including cell wall that provides a rigid framework that support and maintain its shape and keeps it from bursting under hypotonic conditions which is known as their protection, capsules that slime-like layers that surrounds the cell wall, bacterial cell membrane, nucleoid region that contain genetic material genes that is DNA, flagella to moving the cell through a liquid environment and respond to food or poison, pili hairlike structures play a role in exchange og genetic information, endospores that is produced by certain bacteria when starved and can germinate under favorable condition, plasmids are extra-chromosomal DNA,small and circular that are often have genes that code for catabolic enzymes,genetic exchanges and for antibiotic resistance, ribosomes as a workbench for protein synthesis that is receive and translate genetic instructions for the information of specific proteins.
Next, Dr. Parameswari also tought me about viruses that is including prions and also viroids. What I learned about viruses is not a living things because it is only can survive in a host cell. Without a host cell, viruses are nothing. This is because viruses only consist of two major parts that is protein coat alled capsid and hereditary material which is DNA or RNA. Unfortunately, when these viruses found a host, they can be infect animals, plants, human and even bacteria. There are two types of cycle included in their reproductive cycle in two days which is Lytic Cycle and also Lysogeny Cycle. This viruses can be classified according to their genetic material, shape, symmetry of the capsid, presence or absence of the envelope and the type of the host they selected. I also got that viruses that infect bacteria is called bacteriophages. What i knoew about prions is an infectious agent that is composed primarily of protein and propagate by transmittinga mis-folded protein state known as abnormal prion proteins. Prions usually infections in both humans and animals directly causes some diseases including Alzheimer and Parkinson. Apart of prions, there is also viroids which is a small circular RNA molecules without a protein coat and it is typically infect plants that lead to some diseases that losses in agriculture horticulture worldwide.
At the end of this week lecture, Dr. Paramesari gave us an activity in the class on this topic which is doing a Venn Diagram on differences and similarities of prokaryote and eukaryote cells. Not only that, she also ask each group to do some flyers of Most Wanted and Unwanted Bacteria. I did really loves an activity after a lecture as wall as it can tougher and also sharpen our understanding on every topics.
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