[Biology Class Notes] on Binary Fission in Amoeba and Budding in Yeast Pdf

Reproduction is a necessary biological process to continue the existence of a race or species. This process is thus the basis of maintaining the continuity of a species. There are several types of reproduction varying from the simplest asexual type to complex sexual types depending upon the type of the organism. Unicellular organisms reproduce by the simplest type of reproduction of cell division or fission to create their new individuals and continue the species. Binary fission is such a kind of cell division process of the asexual type. Binary fission also involves various steps like a higher organism, as bacterial cells also need to copy their DNA; they have multiple linear rods like chromosomes enclosed in a membrane-bound nucleus, bacterial cells. This process generally occurs when the environmental condition is most favourable.

Amoeba

Amoeba is a single-celled eukaryotic organism that catches food and moves out by extending a fingerlike projection of protoplasm. Amoeba is either free-living in damp environments or parasitic. The shape of the Amoeba is irregular and can be changed according to time and situation.

Classification of Amoeba

• Kingdom: Protozoa

• Class: Tubulinea

• Family: Amoebidae

• Order: TubulinIndia 

• Genus: Amoeba

Amoeba is extremely diverse in nature so they reproduce using varieties of different modes such as binary fission, spore formation and even sexually.

Most commonly amoeba undergoes asexual reproduction through binary fission under this reproduction process parent cell divides into two new daughter cells and during this process, both duplication and division of genetic material of the parent cell occur and each daughter cell receives a single copy of parent genetic material. As binary fission is a primitive reproduction process in prokaryotes, all resulting daughter cells are genetically identical to each other and parent cell,  there is no spindle apparatus formation in the cell during this type of reproduction process.

Binary Fission in Amoeba Happens Through Various Steps, They Are:

1. Replication of DNA: Under this process, the DNA of bacteria replicates its chromosome and just doubles its essential contents.

2. Growth of Cell: After replication, the process cell starts growing by increasing the amount of cytoplasm along with organelles. Another important part of this stage is that two strands move toward opposite poles.

3. Segregation of DNA: The cell elongated with the furrow in the middle. The two chromosomes also separate themself.

4. Splitting of Cell: A new cell wall is formed and a cell splits at the centre dividing the parent cell into two daughter cells.

The Shape of Amoeba Under Compound Microscope

When we viewed Amoeba in a microscope it looks like a colourless transparent jelly moving across the field slowly as they change their shape. Finger-like projection of Amoeba is known as Pseudopodia, as Pseudo means false and Podolia means legs.

How Does Binary Fission in Amoeba and Budding yeast happen?

Binary Fission in Amoeba

Binary fission is a kind of asexual reproduction where a body separates into two new bodies with each body with its own copy of DNA. In this process, the body first duplicates its genetic materials and then the body divides into two bodies by the process of cytokinesis. This kind of reproduction is seen in Amoeba and other organisms. In this way, a species produces its own kind and continues to exist generation wise. Asexual reproduction in eukaryotes is binary fission. Binary fission usually occurs when the environmental conditions are favourable.

Amoeba is a unicellular eukaryotic protozoan with no single taxonomic group looking like a transparent colourless mass of jelly. It has a very diverse nature and uses various modes of reproduction. They reproduce by binary fission, spore formation and sometimes even sexually. 

Budding:

Another type of asexual reproduction is budding. Budding is a method in which the organism produces an outgrowth or a bud due to cell division under favourable conditions.  A new organism develops from the outgrowth or bud. The genetic material in the daughter cells is identical to each other and also to the parent cell since this is a primitive type of asexual reproduction. This type of reproduction through vegetative growth of budding is mainly seen in yeast and hydra. 

Yeast is a unicellular eukaryote belonging to the fungus kingdom, often used in the fermentation process. Yeast usually reproduces by the method of budding.

How Budding in Yeast Occurs:

It is a kind of vegetative asexual reproduction, where buds are formed on the parent cell and they form new individuals from these buds. The nucleus of the parent nucleus divides into the daughter nucleus and moves to the daughter cell. They are genetically identical to their parents.

Budding Involves Various Steps Like:

1. Formation of Bud: buds are formed on the parent body.

2. Division of Cytoplasm: cytoplasm equally divides into daughter cells.

3. Termination of Bud into Different Individuals: formed buds terminate into separate daughter bodies.

MCQ Based on Budding and Binary Fission:

1. Budding is most commonly seen in:

1. Yeast

2. Grasses

3. Amoeba

4. Spirogyra

Answer: Yeast

2. Amoeba most commonly reproduce in or with which mode:

1. Spore formation

2. Binary fission

3. Sexually 

Answer: Binary fission

3. Binary fission show similarity with which mode of division:

Mitosis division

1. Meiotic division

Answer: Mitosis division

4. Which event occurs first in amoeba during binary fission:

1. Cytokinesis

2. Karyokinesis

Answer: Cytokinesis