CBSE Biology Experiment Studying Binary Fission in Amoeba and Budding in Yeast with the Help of Prepared Slides

Biology Experiment - Studying Binary Fission in Amoeba and Budding in Yeast with the Help of Prepared Slides 

Reproduction is an essential life process where organisms procreate or replicate their number by creating offspring. It is observed in both unicellular organisms and multicellular organisms. Some organisms reproduce by the involvement of a single parent organism which is called asexual reproduction. Unicellular organisms like Amoeba reproduce asexually when the parent cells undergo splitting. Yeast reproduces by asexual methods involving the formation of new buds.

Table of Contents

The following article contains: 

• Aim

• Apparatus required

• Theory

• Procedure 

• Observations

• Result 

• Precautions

Aim

To study the binary fission in Amoeba and budding in yeast by observing prepared slides.

Apparatus Required

• Permanent slides showing binary fission in Amoeba.

• Permanent slides showing budding in yeast.

• Compound microscope

Theory 

• Reproduction is the process where new individuals are produced from the parent organisms. It is essential for the perpetuation of species. Asexual and sexual modes of reproduction are the two types. 

• Asexual reproduction is the process wherein the organisms reproduce without gamete formation. 

• Since there is no involvement of gametes and their fusion, the newly formed organisms are genetically identical to the parent organisms.  

• Budding and binary fission are two methods of asexual reproduction in unicellular organisms.  

• Binary fission is the asexual method of reproduction where the parent cell divides into two individual and identical daughter cells. 

• Asexual reproduction in Amoeba is an example of binary fission. 

• In Amoeba, the parent cell nucleus undergoes division followed by a cytoplasmic amitotic division which produces two daughter cells that grow into an adult. 

• Budding in yeast is a process where a new bud forms on the mature cells. It eventually develops into a new organism after separating from the parent cells. If the new bud does not break off, it forms a chain of yeast cells. 

Procedure

1. Place the prepared slide of Amoeba under a compound microscope and adjust the mirror to focus more light on the slide. 

2. Observe the slide carefully first under the low power microscope followed by high power and note down the observations of various stages of binary fission. 

3. Follow the above steps for the prepared slide of yeast as well and note down the observations of various stages of budding.

Observations

1. In the prepared Amoeba slide, 

• Initially, the Amoeba is irregular in shape and later withdrew its pseudopodia and became round-shaped. 

• The centre nucleus elongates and is divided into two daughter nuclei.

• This is followed by the cytoplasmic division that arose from a constriction that further formed two daughter Amoeba cells.

Binary fission in Amoeba

2. In the prepared slide of yeast,

• A mature yeast cell is large and round. 

• Small bulb-like projections arose on the parent cell membrane.

• The parent cell nucleus elongated and divided into two nuclei.

• One daughter nuclei marched into the bulb-like projection.

• The bud separated from the parent yeast cell.

Budding in yeast

Result

The given slides show the asexual reproduction in unicellular Amoeba and yeast where a single parent cell is involved in the generation of daughter cells.

Precautions

• Place the slides carefully by adjusting the mirror to focus better light.

• Firmly place the slide on the microscope stage.

• Do not tilt the microscope while observing.

• Clean the microscope stage before and after every use.

Lab Manual Questions

1. How are the prepared slides of Amoeba and yeast observed?

Ans. The prepared slides of Amoeba and yeast are observed under a compound microscope. The slides are placed on the stage and observed by focusing light onto the slide.

2. What is the division that occurs first in binary fission?

Ans. In binary fission, the nuclear division occurs first which is followed by a cytoplasmic division.

3. Why is budding referred to as asexual reproduction?

Ans. Budding involves a single-parent organism. In yeast, the single mature cell gives rise to a small bud which develops into an adult yeast cell. Since it involves a single parent cell without the intervention of male and female gametes, budding is referred to as an asexual mode of reproduction.

Viva Questions 

1. An organism is divided into two daughter cells. What is the type of reproduction that it followed?

Ans: If an organism divides into two identical daughter cells, it must have undergone binary fission.

2. Give an example of an organism that reproduces by binary fission other than an Amoeba.

Ans: Binary fission is common among unicellular organisms like Amoeba and paramecium.

3. How does the cytoplasm divide after a nuclear division in binary fission?

Ans: The cytoplasmic division in binary fission is an amitotic division that proceeds by forming a central furrow which deepens up forming two daughter cells.

4. Give an example of budding other than yeast.

Ans: Hydra is a multicellular freshwater organism that reproduces by budding.

5. Which is another method that Amoeba reproduces?

Ans: Under normal conditions, Amoeba reproduces by binary fission but under unfavourable conditions, it adopts multiple fission for ensured survival and reproduction.

6. What are the two types of reproduction?

Ans: Asexual and sexual modes are the two types of reproduction.

7. In your view what is a faster mode of reproduction, sexual reproduction or binary fission?

Ans: Binary fission which is an asexual mode of reproduction is a faster mode of reproduction since it does not involve gamete formation and their fusion.

8. What are the applications of yeast?

Ans: Yeast is used in bakeries for fermentation and rising of dough in the preparation of bread and cakes.

9. How different are the daughter cells from the parent Amoeba?

Ans: Mature Amoeba is larger in size while the two daughter Amoeba cells are small in size but are genetically identical to the parent cell.

10. How different is asexual reproduction from sexual reproduction?

Ans: Asexual reproduction involves single-parent organisms while sexual reproduction involves the gametes formed from two parents, the male and female.

Practical Based Questions

1. An example of budding is 

1. Yeast

2. Paramecium

3. Amoeba

4. Tapeworm 

Ans: A) Yeast

2. Identify the method which is not an asexual mode of reproduction

1. Budding

2. Binary fission

3. Regeneration

4. Fertilisation

Ans: D) Fertilisation

3. Which of the following follows binary fission?

1. Amoeba

2. Paramecium

3. Both a and b

4. Hydra

Ans: C)  Both a and b

4. Asexual reproduction involves

1. Gametes fusion occurs

2. Gametes are produced

3. Two parents crossover

4. Single parent organism

Ans: D) Single parent organism

5. The division of the nucleus is called

1. Cytokinesis

2. Amitosis

3. Karyokinesis

4. Meiosis

Ans: C) Karyokinesis

6. The asexual mode of reproduction by the formation of a bulb-like structure is called

1. Binary fission

2. Budding

3. Regeneration

4. Vegetative propagation

Ans: B) Budding

7. Asexual reproduction resulting in two identical daughter cell formation is

1. Budding

2. Binary fission

3. Multiple fission

4. Regeneration

Ans: B) Binary fission

8. Locomotion in Amoeba is by

1. Flagella

2. Cilia

3. Legs

4. Pseudopodia

Ans: D) Pseudopodia

Conclusion

The given slides display binary fission and budding which are asexual modes of reproduction. Since only a single-parent individual is involved, both methods are asexual.