Cells,+Tissues,+Organs+and+Systems

Cells, Tissues, Organs and Systems Cells Cells are the building blocks of life. Most animals and plants are made up of thousands of cells. A cell is the smallest unit of life. There are basically two types of cells: ** Plant Cells & Animal Cells ** Cells are alive. They do everything that living things do to stay alive. Cells have different parts to do all these functions. Below is a picture that shows all the parts of an animal and plant cell. __ Protoplasm __ A cell consists of a mass of living matter called protoplasm. It includes the cell surface membrane, the nucleus and the cytoplasm, where numerous reactions take place. __ Nucleus __ The nucleus consists of a small spherical mass of denser protoplasm, the nucleolus, surrounded by a membrane called the nuclear envelope. It is embedded within the cytoplasm of the cell and controls the normal cell activities. Within the cells, there are a network of long thread-like structures called the chromatin, spherical structures called the nucleoli and a nuclear envelope. The chromatin threads contain hereditary materials, i.e. materials inherited from the parents. The nucleolus plays a part in building up of proteins. A nuclear envelope separates the nuclear content from the surrounding cytoplasm. Responsible for cell production Nucleus is needed for the continued life of the cell, as well as for the repair of worn-out parts. __ Cytoplasm __ The part of the protoplasm surrounding the nucleus is called the cytoplasm. It usually forms the larger part of the cell and is the place where most life processes occur. It usually forms the larger part of the cell and is the place where most life processes occur. The part of the protoplasm surrounding the nucleus is called the cytoplasm. Embedded in the cytoplasm are some important organelles: • Mitochondria • Chloroplast (for plants only) • Vacuole. • Centrioles • Ribosome __Cytoplasm - Mitochondria__ • Involved in the release of energy from food substances during cell respiration • Small spherical or rod-shaped __Cytoplasm – Chloroplast (Plants only)__ <span style="font-family: 'Times New Roman','serif';">• Sites where plants make their food <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l12 level1 lfo2; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Combine together carbon dioxide and water, and using the energy from sunlight to make sugar (glucose) __Cytoplasm - Vacuoles__ <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l6 level1 lfo3; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• A vacuole is a fluid-filled space enclosed by a membrane <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l6 level1 lfo3; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Animal cells may have many small vacuoles but they are usually not permanent. Vacuoles may contain water and food substances <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l6 level1 lfo3; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• A plant cell usually has a large central vacuole which contains a liquid called cell sap. Cell sap contains dissolved substances such as sugar, mineral salts and amino acids. This large vacuole is enclosed by a membrane called the tonoplast __Cytoplasm – Cell membrane__ <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l21 level1 lfo4; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• The cytoplasm is surrounded externally by a cell membrane (also known as plasma membrane). <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l21 level1 lfo4; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• It is a partially permeable membrane which controls substances entering or leaving the cell. <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l21 level1 lfo4; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Similar membranes may also surround large spaces or vacuoles within the cell. __Cytoplasm – Cell wall (Only in plant cells)__ <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l15 level1 lfo5; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• In a plant cell, there is a cell wall which encloses the whole cell. <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l15 level1 lfo5; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• This cell wall is made of cellulose. It protects the cell from injury. __Cytoplasm – Ribosome__ <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l17 level1 lfo6; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Smallest organelles in the protoplasm <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l17 level1 lfo6; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Produces protein from a set of genetic instructions. <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l17 level1 lfo6; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Floats freely in the cytoplasm. ** Similarities between a plant and animal cell: ** Both plants and animals cells have the following structures: <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l7 level1 lfo7; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Nucleus <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l7 level1 lfo7; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Cell membrane <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l7 level1 lfo7; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Cytoplasm Differences between a plant and animal cell: <span style="display: block; margin: 0cm 0cm 0pt 72pt; mso-add-space: auto; mso-list: l10 level1 lfo8; tab-stops: list 72.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Animal cells usually have many vacuoles while the plant cells only has one large one in the cell <span style="display: block; margin: 0cm 0cm 0pt 72pt; mso-add-space: auto; mso-list: l10 level1 lfo8; tab-stops: list 72.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Animal cells does not has chloroplast but a plant cell has chloroplast <span style="display: block; margin: 0cm 0cm 0pt 72pt; mso-add-space: auto; mso-list: l10 level1 lfo8; tab-stops: list 72.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Animal cells does not have a cell wall but a plant cell has <span style="display: block; margin: 0cm 0cm 10pt 72pt; mso-add-space: auto; mso-list: l10 level1 lfo8; tab-stops: list 72.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Animal cells has its cell filled mostly with cytoplasm while a plant cell only has a thin lining of cytoplasm ** Differences between cells, tissues, organs, etc: ** Many cells will make up a Tissue Many tissues working together will make an Organ Many organs working together will form an Organ system Many organ systems will form an Organism Tissue ** What is a tissue? **   A tissue is a group of cells which have a common origin and a similar structure, which enables them to perform a particular function. ** Tissues in Plants: ** Some examples of plant tissues: <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l4 level1 lfo9; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Epidermal tissue (also known as epidermis) <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l4 level1 lfo9; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Xylem tissue <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l4 level1 lfo9; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Phloem tissue <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l4 level1 lfo9; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Photosynthetic tissue (also known as mesophyll) <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l4 level1 lfo9; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Palisade tissue __ Epidermal Tissue __ <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l11 level1 lfo10; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Also known as epidermis <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l11 level1 lfo10; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Protects the underlying cells of a leaf by preventing water loss and acts as a barrier to fungi and other invaders. __Xylem Tissue__ <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l19 level1 lfo11; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Transports water and dissolved mineral salts to the leaf. __Phloem Tissue__ <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l14 level1 lfo12; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Phloem transports the manufactured food away from the leaf to other part of the plants. __Photosynthetic Tissue__ <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l8 level1 lfo13; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Also known as Mesophyll <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l8 level1 lfo13; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Carries out photosynthesis ** Tissues in Animal: ** Some examples of animal tissues: <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l18 level1 lfo14; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Epithelial tissues <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l18 level1 lfo14; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Muscle tissues <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l18 level1 lfo14; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Connective tissues <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l18 level1 lfo14; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Nerves tissue <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l18 level1 lfo14; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Glandular tissue __Epithelial Tissue__ <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l5 level1 lfo15; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Also known as epithelium <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l5 level1 lfo15; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• This is a sheet of cells which covers the internal and external surfaces of an organ. <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l5 level1 lfo15; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• This tissue lines both the outside (skin) and the inside cavities of an animal. <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l5 level1 lfo15; tab-stops: list 36.0pt; text-indent: -18pt;"><span style="font-family: 'Times New Roman','serif';">• Functions include secretion, absorption, protections, trancellular transport, and sense of touch. __Muscle Tissue__ Divided into 3 main groups Smooth muscle controls slow, involuntary movements such as the contraction of the smooth muscle tissue in the walls of the stomach and intestines. Skeletal muscles function in pairs to bring about the co-ordinate movements of the limb, trunk, jaws, eyeballs, etc. Cardiac muscle tissue plays the most important role in the contraction of the atria and ventricles of the heart. __Connective Tissue__ Divided into 4 main groups <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l23 level1 lfo17; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Dense connective tissue It forms ligaments and tendons. It is densely packed and has great tensile strength. <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l23 level1 lfo17; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Loose connective tissue Holds organs in place <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l23 level1 lfo17; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Reticular connective tissue This is a network of reticular fibers (fine collagen) that form a soft skeleton to support the lymphoid organs (lymph nodes, bone marrow and spleen). <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l23 level1 lfo17; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Adipose tissue Used for cushioning, thermal insulation and energy storage. <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l23 level1 lfo17; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Nerve Tissue Make up the nervous system that carries information within the body. <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l23 level1 lfo17; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Glandular Tissue It forms gland that produces substances to secrete hormones or sweat. Organs ** Organs of Plant ** __What is an organ?__ An organ is a structure made up of different tissues working together for a specific function. Organs in Plants: Some examples of plant organs: __ Leaf __ <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l22 level1 lfo18; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø An organ of photosynthesis (contains photosynthetic tissues). __ Stem __ <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l9 level1 lfo19; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Contains Xylem and phloem tissues and supporting tissues <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l9 level1 lfo19; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Provide support and transport food to other parts of the plants. __Roots__ <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l2 level1 lfo20; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Contain xylem and phloem tissues. <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l2 level1 lfo20; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø These tissues take in the nutrients from the roots and transport them to other parts of the plant. <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l2 level1 lfo20; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Roots serve to anchor the plants to the soil and absorb water and minerals. **Organs in Animals:** Some examples of animal organs: __Stomach__ <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l3 level1 lfo21; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Consist of glandular tissues which secrete digestive juices to digest food <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l3 level1 lfo21; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Muscle tissue which causes stomach to contract and relax and mix the food well with the digestive juices <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l3 level1 lfo21; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Connective tissue which helps to connect the other tissues. __Heart__ <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l24 level1 lfo22; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Circulates blood around the body <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l24 level1 lfo22; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Consist of blood tissue <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l24 level1 lfo22; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Muscle tissue which causes heart to contract and expand to circulate blood <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l24 level1 lfo22; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Connective tissue which helps to connect the other tissues. Organ System **What is an organ system?** An organ system consists of several organs working together to perform a special function, e.g. the digestive system. Organ systems in Human: __Respiratory system__ <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l1 level1 lfo23; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Lungs, windpipe and mouth. <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l1 level1 lfo23; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Supplies the body with oxygen and remove carbon dioxide. <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l1 level1 lfo23; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Allows animal to breathe in order to carry out respiration. __Digestive system__ <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l13 level1 lfo25; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Breaks down food into smaller and soluble substances that can be absorbed by the blood. __ Circulatory system __ <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l16 level1 lfo24; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Made up of heart, capillaries, arteries and veins. <span style="display: block; margin: 0cm 0cm 10pt 36pt; mso-list: l16 level1 lfo24; tab-stops: list 36.0pt; text-indent: -18pt;"> Ø Allows animal to circulate blood around the body so that different parts of the body will receive food, oxygen, etc in order to work. With that, I have come to the end of introducing cells, tissues, organs and systems
 * 1)  Smooth muscle tissue
 * 1)  Skeletal muscle tissue
 * 1)  Cardiac muscle tissue

Reflections
After learning about cells, tissues, organs and systems, I feel that I have really gained a lot more knowledge about the plant's and the human body's system. During primary school, we were only taught very basic stuff. However, during this lesson, we not only went through most of what we had learnt before, we still learnt more and gained more knowledge on that particular topic. I really like this topic as I feel that the body parts or both animals and plant are really very amazing and I feel that it is very cool being able to learn about it.