Which of the following options is a creature without a cellular structure .

Macrophages are formed by the differentiation of monocytes in the blood through blood vessels. White blood cells located in tissues are derived from monocytes, and macrophages and monocytes are phagocytic cells.

The cells are mouse mononuclear macrophages, blood cells, are commonly used primary macrophages, commonly used in inflammatory cell models, I bought this cell in Nanjing Kebai Biology, the quality is good, there is technical support throughout the process, and the after-sales service is also very good, you can take a look.

I choose BSARS virus.

Viruses are a special class of organisms without a cell structure, their structures are basically similar, generally composed of protein shells and genetic material inside, and the other four types of organisms such as animals, plants, bacteria, and fungi are all made of cells.

The cell structure is divided into: animal cells and plant cells.

Cell structure is the same as other systems, cells also have boundaries, several components of division of labor and cooperation, and information centers to regulate cell metabolism and heredity. The structure of cells is complex and delicate, and various structural components are coordinated and coordinated, so that life activities can be self-regulated and highly orderly in a changing environment.

Looking at the cells of a plant under an optical microscope, you can see that its structure is divided into the following four parts:

The cell wall is located in the outermost layer of plant cells and is a thin layer of transparent walls. It is mainly composed of cellulose and pectin, and the pores are large, and the molecules of the substance can be freely permeated. The cell wall plays a supporting and protective role for the cell.

Cell Membrane The inside of the cell wall is clinging to a very thin membrane called the cell membrane. This thin film composed of protein molecules and lipid molecules, small molecules such as water and oxygen can pass freely, while some ions and macromolecular substances cannot pass freely, so in addition to protecting the inside of the cell, it also has the role of controlling the entry and exit of substances: neither let useful substances arbitrarily exudate out of the cell, nor allow harmful substances to easily enter the cell.

Cell membranes are not easily resolved under a light microscope. Observation with electron microscopy shows that cell membranes are mainly composed of protein molecules and lipid molecules. In the middle of the cell membrane, there is the phospholipid bilayer, which is the basic skeleton of the cell membrane.

On the outer and inner sides of the phospholipid bilayer, there are many spherical protein molecules that are embedded in the phospholipid layer at different depths (Figure 3-1-2) or overlay the surface of the phospholipid layer. Most of these phospholipid molecules and protein molecules are fluid, so to speak, the cell membrane has a certain fluidity. This structural feature of the cell membrane is very important for it to complete various physiological functions.

Cytoplasm A viscous and transparent substance encased in a cell membrane called cytoplasmic matrix. In the cytoplasm, some refractive particles can also be seen, most of these particles have a certain structure and function, similar to various organs of organisms, so they are called organelles. For example, in the mesophyll cells of green plants, many green particles can be seen, which is an organelle called chloroplast.

Photosynthesis of green plants takes place in chloroplasts. In the cytoplasm, one or several vacuoles are often also seen, which are filled with fluid, called cell sap. In mature plant cells, vacuoles merge into a single vacuole, which accounts for most of the volume of the entire cell.

Answer]: A This question examines the structure of the virus. The basic structure of bacteria is the cell wall, cell membrane, cytoplasm and nucleoplasm. The virus consists only of a core punch and a protein capsid and has no cellular structure. So the answer is a.

Answer d Analysis: Cells are the basic unit of structure and function of living organisms, and not all living things have cells, such as viruses

Answer: The basic units of biological structure and function such as plants, animals, bacteria, and fungi are cells That is to say, animals, plants, bacteria, and fungi are all organisms composed of cells Only the structure of viruses is simple, and its structure is composed of protein shells and internal genetic materials, and there is no cell structure In the above options, the rat woman is an animal; Peach trees are plants; Shiitake mushrooms are fungi; Avian influenza viruses are viruses and do not have a cellular structure

Comment: Organisms that do not have a cellular structure are only viruses, which should be remembered

Answer D Question Analysis: Cells are the basic units that make up the structure and function of living organisms, but not all organisms are made of cells, such as viruses, there is no barrier to the cellular structure, and the body structure is composed of the outer shell of proteins and the genetic material inside.

Test point: This question examines the noisy composition of organisms, comments: Most organisms are composed of cells, and only a simple case of viruses is an exception, just memorize it.

Viruses are composed of nucleic acids and proteins, and are a class of microorganisms that do not have a cellular structure and have life characteristics such as genetics and replication.

Answer D Question Analysis: Cells are the basic units of structure and function of organisms, and not all organisms have cells, such as: viruses Plants, animals, bacteria, fungi and other organisms simplify the basic units of structure and function are fine imitation podrafts That is to say, animals, plants, bacteria, and fungi are all organisms composed of cells Only the structure of viruses is simple, and its structure is composed of protein shells and internal genetic material, and there is no cell structure In the above options, trees are plants, Zebras are animals and bacteria, both made of cells; Influenza viruses belong to viruses and do not have a cellular structure Hence, organisms that do not have a cellular structure are viruses.

Test Center: This test is about the structural characteristics of the virus.

Comments: For such topics, students should remember that cells are the basic unit of structure and function of organisms, and not all organisms have cells, for example: viruses Most organisms are made of cells, only viruses are an exception, and they can be remembered alone For the knowledge of viruses, students usually have less contact with them and are easy to ignore.

Answer B Analysis: This question examines the structural characteristics of a virus, a virus is a microorganism with a simple structure Cells are the basic units of structure and function of organisms, and not all organisms have cells

Answer: a. P. parvosparis is a single-celled organism, which is composed of only one cell in the whole body, so it does not meet the topic

b. Viruses have no cell structure, and the whole body is only composed of protein shells and internal genetic materials, so it is in line with the topic

c, d, fungi have a cellular structure, fungi have unicellular such as yeast, and there are also multicellular such as mushrooms, so it does not fit the topic

Therefore, selection: b Comments: Most organisms are composed of cells, only viruses are a case of withering, and you can remember it alone

Answer D Question Analysis: Cells are the basic units that make up the structure and function of living organisms, but not all organisms are made up of cells, such as viruses, there is no cell structure, and the body structure is composed of the outer shell of proteins and the genetic material inside.

Test point: This question examines the composition of organisms, comments: The eldest brother is aware that most organisms are composed of cells, with the exception of viruses.

Answer] A Answer Analysis] Test Question Analysis: The pathogen of mad cow disease, bacteriophage, and hepatitis B virus are all viruses and have no cell structure, while Methanobacter is a bacterium and belongs to the pure collapse of prokaryotic cells; So choose A.

Test point: The structure of the hand of an organism.

Comments: The test questions are relatively simple and focus on the examination of basic knowledge.