Next, we were required to answer the question before the lecture of new topic start. I knew a little bit about what does the endosymbiotic theory suggest and I can describe the structures, functions, and characteristics of the mitochondrion and chloroplast that have led scientists to propose the endosymbiotic theory. At the end of this lecture, we should able be able to describe the origin of mitochondria and chloroplast.
After had learned this topic, I had knew that the endosymbiosis theory suggest that eukaryotes arose from a symbiotic relationship between various prokaryotes, heterotrophic (aerobic) bacteria became mitochondria, cyanobacteria (photosynthetic) became chloroplasts and host cell was a large eukaryotic cell.
The origin of eukaryotic cell
Those are the evidence for symbiosis :
Membranes — Mitochondria have their own cell membranes, just like a prokaryotic cell does.
DNA — Each mitochondrion has its own circular DNA genome, like a bacteria's genome, but much smaller. This DNA is passed from a mitochondrion to its offspring and is separate from the "host" cell's genome in the nucleus.
bacteria/mitochondria structural comparison
Reproduction — Mitochondria multiply by pinching in half — the same process used by bacteria. Every new mitochondrion must be produced from a parent mitochondrion in this way; if a cell's mitochondria are removed, it can't build new ones from scratch.
bacteria/mitochondria reproduction
Then we were required to do the SCL activity in group. We were given a task to complete the Venn diagram to compare and contrast of chloroplasts and mitochondria.
After that, we had learned about the division cycle of plant cell and totipotency. At the end of this lecture I will able to describe different stages of cell cycle and what is entails, apply cell cycle to plant growth and development, define totipotency and explain types of totipotent cells in plants and lastly can relate the control mechanisms involved in cell cycle with plant totipotency.
Eukaryotic cell cycle consists of : 1) GAP 1 (G1) phase-growth and doubling of cell organelles
2) Synthesis (S) phase- DNA replication occurs
3) GAP 2 (G2) phase-Preparation for cell division
4) M phase-division of the nucleus and cell
Eukaryotic cell cycle
Plant cell cycle-Mitosis
The passage of a cell through the cell cycle is controlled by proteins in the cytoplasm which is Cyclins.
· a G1 cyclins (D cyclins)
· S-phase cyclins (cyclin A)
· Mitotic cyclins (B cyclins)
· Their leves in the cell rise and fall with the stages of the cell cycle
The regulation of cell cycle
Plant growth can be by increasing cell numbers or increasing cell size. Body complexity is another dimension of plant growth. Plant have open growth strategy-continously produce new organs throughout their life due to the presence of a tissue called meristematic tissue. Meristematic tissue can be found in the following locations :
· Near tips of roots and stems called apical meristems
· In the buds and nodes of stems – axillary meristems
· In the cambium between the xylem and phloem in dicotyledonous trees and shrubs
· Under the epidermis of dicotyledonous trees and shrubs (cork cambium)
· In the pericycle of roots, producing branch roots/lateral roots.
Meristematic tissue
Next, we had learned about totipotency. What is totipotency? Totipotency is the ability of a single cell to divide and produce all of the differentiated cells in an organism. Spores and Zygotes are examples of totipotent cells. In the spectrum of cell potency, totipotency represents the cell with the greatest differentiation potential. Loss of totipotency is probably due to the genetic or epigenetic. Callus is made up of a group of unorganized loose parenchyma cells which proliferate from parent cells
.
Finally we learned about the factors that affect cellular totipotency. The factors that affect cellular totipotency are source of explant, nutrient media and constituents and culture environment. I love this topic because I had learned the new things in my life. I had never knew about totipotency before.
After had learned this topic, I had knew that the endosymbiosis theory suggest that eukaryotes arose from a symbiotic relationship between various prokaryotes, heterotrophic (aerobic) bacteria became mitochondria, cyanobacteria (photosynthetic) became chloroplasts and host cell was a large eukaryotic cell.
The origin of eukaryotic cell
Those are the evidence for symbiosis :
Membranes — Mitochondria have their own cell membranes, just like a prokaryotic cell does.
DNA — Each mitochondrion has its own circular DNA genome, like a bacteria's genome, but much smaller. This DNA is passed from a mitochondrion to its offspring and is separate from the "host" cell's genome in the nucleus.
bacteria/mitochondria structural comparison
Reproduction — Mitochondria multiply by pinching in half — the same process used by bacteria. Every new mitochondrion must be produced from a parent mitochondrion in this way; if a cell's mitochondria are removed, it can't build new ones from scratch.
bacteria/mitochondria reproduction
Then we were required to do the SCL activity in group. We were given a task to complete the Venn diagram to compare and contrast of chloroplasts and mitochondria.
After that, we had learned about the division cycle of plant cell and totipotency. At the end of this lecture I will able to describe different stages of cell cycle and what is entails, apply cell cycle to plant growth and development, define totipotency and explain types of totipotent cells in plants and lastly can relate the control mechanisms involved in cell cycle with plant totipotency.
Eukaryotic cell cycle consists of : 1) GAP 1 (G1) phase-growth and doubling of cell organelles
2) Synthesis (S) phase- DNA replication occurs
3) GAP 2 (G2) phase-Preparation for cell division
4) M phase-division of the nucleus and cell
Eukaryotic cell cycle
Plant cell cycle-Mitosis
The passage of a cell through the cell cycle is controlled by proteins in the cytoplasm which is Cyclins.
· a G1 cyclins (D cyclins)
· S-phase cyclins (cyclin A)
· Mitotic cyclins (B cyclins)
· Their leves in the cell rise and fall with the stages of the cell cycle
The regulation of cell cycle
Plant growth can be by increasing cell numbers or increasing cell size. Body complexity is another dimension of plant growth. Plant have open growth strategy-continously produce new organs throughout their life due to the presence of a tissue called meristematic tissue. Meristematic tissue can be found in the following locations :
· Near tips of roots and stems called apical meristems
· In the buds and nodes of stems – axillary meristems
· In the cambium between the xylem and phloem in dicotyledonous trees and shrubs
· Under the epidermis of dicotyledonous trees and shrubs (cork cambium)
· In the pericycle of roots, producing branch roots/lateral roots.
Meristematic tissue
Next, we had learned about totipotency. What is totipotency? Totipotency is the ability of a single cell to divide and produce all of the differentiated cells in an organism. Spores and Zygotes are examples of totipotent cells. In the spectrum of cell potency, totipotency represents the cell with the greatest differentiation potential. Loss of totipotency is probably due to the genetic or epigenetic. Callus is made up of a group of unorganized loose parenchyma cells which proliferate from parent cells
.
Finally we learned about the factors that affect cellular totipotency. The factors that affect cellular totipotency are source of explant, nutrient media and constituents and culture environment. I love this topic because I had learned the new things in my life. I had never knew about totipotency before.
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