Plant cell and animal cell diagram class 8

First of all, both plants and animal cells have a cell membrane. A cell wall is more of a structural layer outside the cell membrane, mainly composed of cellulose but has other things, causing rigidity. Animals are fleshy and malleable because they lack the rigidity caused by a cell wall. We do however have muscles and bones(stiffness is caused by the matrix and NOT actual cells) to stand upright. While plants are stiff (in comparison). As for why, stiffness and rigidity are a form of protection and also the reason as to how plants can grow into complex shapes maximizing there potential for further plant growth. It is not really a "necessity" but is useful. Now how come animals did not evolve in such a way. Rigidity impedes on movement. Having such rigid cells would mean we have to trade off our wide range of movement. Plants getting there energy from the sun, don't need that much movement. However, animals consume there energy through other organisms. This lack of self-suffiency means that animals have to "hunt" for food or at the very least having fleshy bodies capable of more movement is useful in that aspect. The nucleolus is a region within the nucleus. The nucleolus is the site of rRNA transcription and ribosomal subunit assembly. In the future, for questions like this I encourage you to search on the Khan Academy website — for example, doing this for "nucleolus" would lead you to this material: Does that help? - [Voiceover] Let's give ourselves an overview, or synth...

CBSE Study Material • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • According to the CBSE Syllabus 2023-24, this chapter has been removed from NCERT Class 8 Science textbook. Early Days of Cells Cells Cells are the fundamental structural units of living organisms and the basic units of life. Robert Hooke discovered the cell in the year 1665 from a thin section of cork under a self-made microscope. For more information on Cell Structure and Its Function, watch the below video World of Cells Prokaryotic & Eukaryotic cells Prokaryotic – Size: generally small ( 1-10 µm), Where 1 µm = 10 − 6m. • The nucleus is not well defined and known as a nucleoid. • Single, circular chromosome. • Membrane-bound organelles are absent. For example, Bacterial cell Eukaryotic – Size: generally large ( 5-100 µm). • The nucleus is well-defined and surrounded by a nuclear membrane. • Possess more than one linear chromosome. • Membrane-bound cell organelles are present. For example, Human cells. Cell structure in Eukaryotic cells • Most eukaryotes are multicellular. ...

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24-03-2022 12:29 PM IST Priyanka Chaudhary The chapter discusses cells, their shapes, size, and types of organisms based on the number of cells. It also discusses the structure of the cell and the difference between plant cells and animal cells. What is a Cell? All organisms are made of smaller parts called organs. Organs are made of still smaller parts. Cells were first observed in cork by Robert Hooke in 1665. The smallest living part of an organism is a ‘cell’. Some cells are big enough to be seen with the unaided eye. Hen’s egg is an example. Shapes of cells Cells exhibit a variety of shapes. Amoeba, a unicellular organism has no definite shape. A white blood cell (WBC) in human blood is an example of a single cell that can change its shape and size. Generally, cells are round, spherical or elongated. They may be spindle-shaped (long and pointed at both ends). Some cells are branched like the nerve cell or a neuron. Size of cells The smallest cell is 0.1 to 0.5 micrometre in bacteria. The largest cell is the egg of an ostrich. The size of the cells has no relation with the size of the body of an organism. The size of the cell is related to its function. Unicellular and multicellular organisms Organisms made of more than one cell are called multicellular organisms. Single-celled organisms (Organisms made up of a single cell) are called unicellular. They perform all the necessary functions that multicellular organisms perform. In Multicellular organisms, the functions ar...

Plant Cells - Definition, Diagram, Structure & Function The cell is the basic unit of life in all organisms. Like humans and animals, plants are also composed of several cells. The plant cell is surrounded by a cell wall which is involved in providing shape to the plant cell. Apart from the cell wall, there are other organelles that are associated with different cellular activities. Let us have a detailed look at the plant cell, its structure, and the functions of different plant cell organelles. Plant Cell Definition “Plant cells are eukaryotic cells with a true nucleus along with specialized structures called organelles that carry out certain specific functions.” Table of Contents • • • • • What is a Plant Cell? Plant cells are eukaryotic cells that vary in several fundamental factors from other eukaryotic organisms. Both plant and animal cells contain a nucleus along with similar organelles. One of the distinctive aspects of a plant cell is the presence of a cell wall outside the cell membrane. Read more: Plant Cell Structure Just like different organs within the body, plant cell structure includes various components known as cell organelles that perform different functions to sustain itself. These organelles include: Cell Wall It is a rigid layer which is composed of polysaccharides cellulose, pectin and hemicellulose. It is located outside the cell membrane. It also comprises glycoproteins and polymers such as lignin, cutin, or suberin. The primary function of the...

\( \newcommand\) • • • • • • • • • • Animal Cells versus Plant Cells Each eukaryotic cell has a plasma membrane, cytoplasm, a nucleus, ribosomes, mitochondria, peroxisomes, and in some, vacuoles; however, there are some striking differences between animal and plant cells. While both animal and plant cells have microtubule organizing centers (MTOCs), animal cells also have centrioles associated with the MTOC: a complex called the centrosome. Animal cells each have a centrosome and lysosomes, whereas plant cells do not. Plant cells have a cell wall, chloroplasts and other specialized plastids, and a large central vacuole, whereas animal cells do not. The Centrosome The centrosome is a microtubule-organizing center found near the nuclei of animal cells. It contains a pair of centrioles, two structures that lie perpendicular to each other. Each centriole is a cylinder of nine triplets of microtubules. The centrosome (the organelle where all microtubules originate) replicates itself before a cell divides, and the centrioles appear to have some role in pulling the duplicated chromosomes to opposite ends of the dividing cell. However, the exact function of the centrioles in cell division isn’t clear, because cells that have had the centrosome removed can still divide; and plant cells, which lack centrosomes, are capable of cell division. Figure \(\PageIndex\): The Centrosome Structure: The centrosome consists of two centrioles that lie at right angles to each other. Each centriol...

Both animal and plant cells have mitochondria, but only plant cells have chloroplasts. Plants don’t get their sugar from eating food, so they need to make sugar from sunlight. This process (photosynthesis) takes place in the chloroplast. Once the sugar is made, it is then broken down by the mitochondria to make energy for the cell. Because animals get sugar from the food they eat, they do not need chloroplasts: just mitochondria. • Think about it: animals are on the move. They need a heart that can pump blood. They need muscles that can flex and relax to move. They need a digestive system that can stretch to hold food. Plants, meanwhile, need to stay upright to photosynthesize. They need to support themselves and their organs; otherwise, they cannot grow. Plants need the walls to support themselves. Animals, on the other hand, have skeletons, but they act as a frame for the other, flexible, fleshy organs that are required for movement. Does this help? Size of an animal cell ranges from 10 to 30 micrometres while for plant cell it ranges from 10 to 100 micrometers. 1 micrometer is 1/1000 of a millimetre. And non-living things do not have a cell. They are not living and thus don't need any of our body systems. They just need a structure, no body systems, thus no cells. So non living things don't need cells. Hope that this answers your question.

Both animal and plant cells have mitochondria, but only plant cells have chloroplasts. Plants don’t get their sugar from eating food, so they need to make sugar from sunlight. This process (photosynthesis) takes place in the chloroplast. Once the sugar is made, it is then broken down by the mitochondria to make energy for the cell. Because animals get sugar from the food they eat, they do not need chloroplasts: just mitochondria. • Think about it: animals are on the move. They need a heart that can pump blood. They need muscles that can flex and relax to move. They need a digestive system that can stretch to hold food. Plants, meanwhile, need to stay upright to photosynthesize. They need to support themselves and their organs; otherwise, they cannot grow. Plants need the walls to support themselves. Animals, on the other hand, have skeletons, but they act as a frame for the other, flexible, fleshy organs that are required for movement. Does this help? Size of an animal cell ranges from 10 to 30 micrometres while for plant cell it ranges from 10 to 100 micrometers. 1 micrometer is 1/1000 of a millimetre. And non-living things do not have a cell. They are not living and thus don't need any of our body systems. They just need a structure, no body systems, thus no cells. So non living things don't need cells. Hope that this answers your question.

CBSE Study Material • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • According to the CBSE Syllabus 2023-24, this chapter has been removed from NCERT Class 8 Science textbook. Early Days of Cells Cells Cells are the fundamental structural units of living organisms and the basic units of life. Robert Hooke discovered the cell in the year 1665 from a thin section of cork under a self-made microscope. For more information on Cell Structure and Its Function, watch the below video World of Cells Prokaryotic & Eukaryotic cells Prokaryotic – Size: generally small ( 1-10 µm), Where 1 µm = 10 − 6m. • The nucleus is not well defined and known as a nucleoid. • Single, circular chromosome. • Membrane-bound organelles are absent. For example, Bacterial cell Eukaryotic – Size: generally large ( 5-100 µm). • The nucleus is well-defined and surrounded by a nuclear membrane. • Possess more than one linear chromosome. • Membrane-bound cell organelles are present. For example, Human cells. Cell structure in Eukaryotic cells • Most eukaryotes are multicellular. ...

\( \newcommand\) • • • • • • • • • • Animal Cells versus Plant Cells Each eukaryotic cell has a plasma membrane, cytoplasm, a nucleus, ribosomes, mitochondria, peroxisomes, and in some, vacuoles; however, there are some striking differences between animal and plant cells. While both animal and plant cells have microtubule organizing centers (MTOCs), animal cells also have centrioles associated with the MTOC: a complex called the centrosome. Animal cells each have a centrosome and lysosomes, whereas plant cells do not. Plant cells have a cell wall, chloroplasts and other specialized plastids, and a large central vacuole, whereas animal cells do not. The Centrosome The centrosome is a microtubule-organizing center found near the nuclei of animal cells. It contains a pair of centrioles, two structures that lie perpendicular to each other. Each centriole is a cylinder of nine triplets of microtubules. The centrosome (the organelle where all microtubules originate) replicates itself before a cell divides, and the centrioles appear to have some role in pulling the duplicated chromosomes to opposite ends of the dividing cell. However, the exact function of the centrioles in cell division isn’t clear, because cells that have had the centrosome removed can still divide; and plant cells, which lack centrosomes, are capable of cell division. Figure \(\PageIndex\): The Centrosome Structure: The centrosome consists of two centrioles that lie at right angles to each other. Each centriol...