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Binary Fission

Class 10th Science Lab Manual CBSE Solution

Lab Experiment 12
Question 1.

AIM

To study (a) binary fission in Amoeba, and (b) budding in yeast with the help of prepared permanent slides.


Answer:

MATERIALS REQUIRED


Compound microscope, permanent slides of binary fission in Amoeba and budding in yeast, worksheet, pencil, eraser, sharpener, etc.


THEORY


1. Reproduction is one of the basic characteristics features of life being organisms.


2. An organism reproduces, to form individuals of its own kind.


3. Reproduction may be either sexual or asexual in living organisms.


4. The type of reproduction taking place without fusion of gametes is called asexual reproduction.


5. Sexual reproduction is a type of reproduction in which male and female gametes are involved.


6. Asexual reproduction involves only one parent cell and is common in lower organisms. It is a process in which rapid multiplication in which the new organisms produced are genetically identical to the parent.


7. Asexual reproduction can be of various types, such as binary fission, multiple fission, budding, fragmentation, sporulation, and vegetative propagation.


Binary Fission- In this type of reproduction, parent cell divides into two small, nearly equal sized identical daughter cells. The two daughter cells then grow into an adult organism.



Budding-In this type of reproduction a small bud-like outgrowth develops at the parent cell. This bud enlarges in size. The nucleus also enlarges in size and divides to form two nuclei. Out of these two nuclei, one goes into developing bud. When the bud attains almost the same size as that of the parent cell, a separating wall is laid down between the bud and parent cell. This bud may detach from the parent cell or may produce another bud over it.


PROCEDURE


1. Choose the slides for binary fission in Amoeba and budding in yeast.


2. Set-up a compound microscope. While looking through the eyepiece, adjust the mirror and diaphragm of the microscope so that the microscope is properly illuminated.


3. Now, place the slide on stage and focus at low power using the microscope.


4. Without removing the slide, now change the focus to high power.

5. Note the observation under the observation subtitle.


OBSERVATIONS


(a) Binary Fission in Amoeba


• This is a type of asexual reproduction in which parent cell divides into two daughter cells.

• Parent cell becomes elongated.

• The division of the nucleus occurs first, and then the cytoplasm divides.

• At the point of fission, constriction appears and deepens to divide the cell into two daughter cells.



(b) Budding in Yeast


In this type of asexual reproduction, a small protuberance or outgrowth arises from the parent body called bud.


• Nucleus divides to form two daughter nuclei of which one passes into the bud.


• The bud now detaches from the parent body and grows independently as a new individual or may remain attached to the parent body, forming a chain of cells.


• Parental identity is not lost.



RESULT



The slides show reproduction by binary fission in Amoeba and budding in yeast.


PRECAUTIONS


1. Always clean the surface of the slide and microscope before use.


2. Always focus the slide, first at low power and then go for high power.


3. While focussing at high power, only use fine adjustment of the microscope.



Viva Questions
Question 1.

What is a reproduction?


Answer:

Reproduction is the ability of an individual to produce a new generation of individuals of same species.It involves the transmission of genetic material from the parental generation to the next generation, Thereby ensuring that characteristics are perpetuated.



Question 2.

What is asexual reproduction?


Answer:

Asexual Reproduction: Production of offspring by a single parent without the involvement of gamete formation is called asexual reproduction.The offspring produced by asexual reproduction is referred to as a clone.



Question 3.

Name various types of asexual reproduction ?


Answer:

Types of asexual production are:

1. Binary fission


2. Multiple fission


3. Budding


4. Fragmentation


5. Sporulation


6. Vegetative Propagation



Question 4.

What are the types of Vegetative propagation ?


Answer:

The Vegetative propagation are of two types:

1. Natural Propagation: It is the natural propagation of plant using root, stem or leaf of another plant.


2. Artificial propagation: It is an artificial propagation of plant using methods like cutting , grafting, layering and tissue culture.



Question 5.

What is Sexual reproduction?


Answer:

Sexual reproduction is the production of offspring by the involvement of two parents.



Question 6.

What is zygote?


Answer:

Zygote is the first cell of next generation. It is formed when male and female gametes fuse together to form a zygote.



Question 7.

What is binary fission?


Answer:

This is a type of asexual reproduction which takes place in Amoeba, In this type of reproduction, parent cell divides into two small, nearly equal sized identical daughter cells. The two daughter cells grow into an adult organism.In binary fission, parent identity is lost.



Question 8.

What is Budding?


Answer:

In this type of asexual reproduction a small bud-like outgrowth develops at the parent cell.This bud enlarges in size.The nucleus also enlarges in cell and get divided into two equal part.Out of these two nuclei, one goes into developing bud; When the bud attains the size of a parent cell, a separating wall is laid down between the bud and parent cell. This bud detaches from the parent cell.

This type of reproduction occurs in yeast, hydra.



Question 9.

Give classification of reproduction in term of parent identity?


Answer:

The parent identity is lost in case of Binary fission , While the Parent identity is not lost in case of Budding.



Question 10.

How is binary fission differ from multiple fission?


Answer:

In binary fission , one cell divides to form two daughter cells, whereas, in multiple fission, one cell forms several daughter cells.



Question 11.

Why do we classify budding, fission as asexual reproduction?


Answer:

We classify budding and fission as asexual reproduction because:

1. involvement of a single parent


2. No , the formation of a gamete



Question 12.

Why sexual reproduction led to more genetic variation than asexual reproduction?


Answer:

In Sexual reproduction due to the involvement of gametes of two different parent organism having different chromosomes configuration.



Question 13.

Give two examples of an organism in which Binary fission and Budding occurs?


Answer:

Binary fission occurs in Amoeba, Paramecium , euglena.

Bidding occurs in Yeast,Hydra.



Question 14.

What are spores?


Answer:

A spore is a small unit involved in asexual reproduction, These microscopic , unicellular structure which contain a small amount of cytoplasm and nucleus.



Question 15.

Amobea is immortal. Comment?


Answer:

Amobea divides into two parts by binary fission , each grows to live, and no dead body is left.