"Reproduction of Bacteria and Fungi" PPT

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"Reproduction of Bacteria and Fungi" PPT

Part 1: Pre-class exercises:

1. When grafting, which part of the structure of the two plants should be closely connected? ( )

A． Xylem B. Phloem C. Cambium D, outer bark

2. The "Thousand-head Chrysanthemum" cultivated by gardeners is colorful and very beautiful. The workers choose thick wild Qinggao, then the whole plant will bloom with chrysanthemums of various colors. The color of the flowers on the grafted branches is like _______ (fill in "scion" or "rootstock"). The key to the survival of the graft is their _______ tightness.

3. A green peach with red flowers is grafted onto a green peach with white flowers. The color of the grafted branches will be ( )

A. red B. white C. pink D. red and white

4. There is a plant called rooting. If you pick off its leaves and put them in moist soil, new individuals will grow. This method of reproduction is called ( )

A. Cutting B. Grafting C. Vegetative propagation D. Tissue culture

Reproduction of bacteria and fungi PPT, Part 2: Learning about bacteria

1. Size of bacteria

Bacteria are single-celled organisms that are very small. The diameter is only 0.5-5 microns.

It takes a microscope to see clearly.

2. The shape of bacteria

3. Structure of bacteria

cell wall

cell membrane

cytoplasm

No nucleus (contains genetic material)

Organisms without a formed nucleus are called prokaryotes

No chloroplasts, no feeding structure, dependent on readily available organic matter

4. Breeding of bacteria

Bacteria reproduce by _________.

This type of reproduction of bacteria belongs to ________, (fill in "sexual" or "asexual") reproduction.

Reproduction of bacteria and fungi PPT, Part 3: Pasteur disinfection method

Some foods cannot be heated at high temperatures (such as milk), otherwise their nutrition and taste will be affected.

For these foods, we can quickly heat them to a certain temperature (generally 60 ℃ ~ 85 ℃) for half a minute, and then cool them quickly. This can kill most microorganisms in the food while maintaining the original taste. This heating method is called pasteurization.

It was invented by French scientist Louis Pasteur.

In Pasteur's retort experiment, (as shown in the picture) the bottle mouth of bottle A is vertically upward, and the bottle mouth of bottle B is an elongated S-shaped retort neck. Boil the broth in the two flasks at the same time and let it cool, then observe the changes in the broth. The experimental variables in this experiment are

(1) The broth in the two flasks A and B is the ______ bottle;

(2) The reason for the spoilage of broth is that a large number of ______ breed in the broth;

(3) The experimental variable in this experiment is______

A． The presence or absence of oxygen B. The length of time the flask is left

C. The presence or absence of microorganisms D. The size of the flask capacity

(4) Pasteur's retort experiment proved that the "spontaneous theory" about the origin of life is ______.

Keywords: Zhejiang Education Edition seventh grade science PPT courseware for the second volume free download, reproduction of bacteria and fungi PPT download, .PPT format;

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"Reproduction of Bacteria and Fungi" PPT courseware:

"The Reproduction of Bacteria and Fungi" PPT Courseware Part One: Mold In a humid and warm environment, some fluffy, flocculent or cobweb-shaped mycelium visible to the naked eye will grow on food, fruits, clothes and many other items. Types of mold: Common molds..

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Update Time: 2024-09-03

This template belongs to science courseware Zhejiang Education Edition Seventh Grade Science Volume 2 industry PPT template

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