Science Review PDF

Science review Prokaryotic Unicellular all bacteria Eukaryotic Have membrane board organelles Oranell means little organ Parts of a Cell: 1.​ Cell Membrane: Acts like a gatekeeper, controlling what enters and exits the cell. 2.​ Rough Endoplasmic Reticulum (ER): Makes and transports protein...

Science review Prokaryotic Unicellular all bacteria Eukaryotic Have membrane board organelles Oranell means little organ Parts of a Cell: 1.​ Cell Membrane: Acts like a gatekeeper, controlling what enters and exits the cell. 2.​ Rough Endoplasmic Reticulum (ER): Makes and transports proteins in vesicles, with ribosomes attached. 3.​ Smooth Endoplasmic Reticulum (ER): Makes and transports fats in vesicles, without ribosomes. 4.​ Cytoplasm: Jelly-like material that keeps organelles floating and is involved in nutrient absorption, transport, and processing. 5.​ Mitochondria: Uses glucose to generate energy (ATP) for the cell. 6.​ Golgi Body: Packages molecules in vesicles and releases them outside the cell, functioning as the cell's post office. 7.​ Cell Wall: Rigid structure that surrounds and supports the cell membrane (only in plant cells). 8.​ Centrosome: Composed of two centrioles, producing spindle fibers for mitosis. 9.​ Centriole: Involved in the production of spindle fibers for mitosis (only in animal cells). 10.​Cytoskeleton: Network of protein strands (microtubules and microfilaments) that provide shape and aid in movement. 11.​Vesicles: Small sacs made by the ER and Golgi body that transport molecules within the cell (present in both plant and animal cells). 12.​Ribosomes: Protein-making machines found on the rough ER and in the cytoplasm. 13.​Chloroplasts: Oval-shaped, green organelles that capture light energy to make sugar (photosynthesis) (only in plant cells). 14.​Central Vacuole: Large storage sac for water, waste, and nutrients (only in plant cells). 15.​Nucleus: Contains DNA, which codes for protein synthesis and acts as the control center of the cell. 16.​Chromatin: Long strands of DNA that make up chromosomes and serve as blueprints for cell parts. 17.​Lysosomes: Small vesicles containing enzymes to break down food and waste (only in animal cells). 18.​Flagella: Long protein structures that whip and spin for movement (present in some animal cells). 19.​Cillia hair like protioens that move like oras to either move the orginisem or more the stuff outside the cell 20.​Pseudopds used to catch prey or move Life of a Cell Interphase: 1.​ G1 Phase: The cell grows and performs normal functions. 2.​ S Phase (Synthesis Phase): DNA replication occurs, and chromosomes are copied. 3.​ G2 Phase: The cell continues to grow, producing proteins and organelles in preparation for division. Mitosis: 1.​ Prophase: ○​ Early Prophase: Chromosomes condense, becoming visible. Each chromosome consists of two sister chromatids joined by a centromere. ○​ Late Prophase (Prometaphase): The nuclear membrane breaks down. Centrioles move to opposite poles, and spindle fibers form, attaching to the centromeres of the chromosomes. 2.​ Metaphase: ○​ Chromosomes align at the cell's equatorial plane, forming the metaphase plate. 3.​ Anaphase: ○​ Spindle fibers shorten, pulling the sister chromatids (now called daughter chromosomes) apart toward opposite poles. 4.​ Telophase: ○​ Mitotic spindle breaks down. ○​ Nuclear membranes reform around each set of chromosomes. ○​ Chromosomes decondense into chromatin. Cytokinesis: ​ In Animal Cells: A cleavage furrow forms, dividing the cell membrane into two daughter cells. ​ In Plant Cells: A cell plate forms between the two new cells, eventually developing into a new cell wall.  ​ -​ Necrosis is uncontrolled cell death due to injury or disease resulting in inflammation -​ Apoptosis is the programmed cell death without causing inflammation -​ Cancer cells are different to healthy normal cells because they divide uncontrollably and can invade other tissues and other areas. -​ Benign tumors are not cancerous and growth doesn't spread to other parts of the body but malignant tumours are cancerous and can invade nearby tissue Cell differentiation is the process by which cells become specialized Stem cells self-renew meaning they can divide and produce more cells they can also become specialist cells but specialist cells cannot become stem cells. -​ Totipotent sells can divide into almost any cell including extra embryonic tissues -​ Pluripotent cells can also form almost any cell except for extra embryonic tissues ​ Extra-embryonic tissues are tissues that develop from the embryo but do not become part of the embryo itself -​ Multipotent cells are a type of stem cell that have the ability to differentiate into a limited range of cell types within a specific tissue or organ -​ Embronics means a period from the fertilization of the egg (zygote) until the end of the eighth week of pregnancy -​ Adult stem cells are Described as multipotent -​ Embryonic stem cells are described as pluripotent  -​ Red blood cells only transfer oxygen -​ a white blood cells heel and fight wounds and infections The dissolved particles on one side of the cell membrane is referred to as concentration The advantage multicellular organisms have over a single cell organisms is that cells can become specialized allowing more diverse work than process to occur Types of tissues Animal 1.​ Epithelial Tissue: ○​ Covers the surfaces of the body and lines internal organs and cavities. ○​ Functions include protection, absorption, secretion, and sensation. ○​ Examples: Skin, lining of the digestive tract, and glands. 2.​ Connective Tissue: ○​ Provides support, binds together, and protects tissues and organs. ○​ Contains a variety of cells embedded in an extracellular matrix. ○​ Examples: Bone, cartilage, blood, and adipose (fat) tissue. 3.​ Muscle Tissue: ○​ Specialized for contraction and movement. ○​ Three types: Skeletal muscle (voluntary movement), cardiac muscle (heart), and smooth muscle (involuntary movements in organs like the stomach). 4.​ Nervous Tissue: ○​ Specialized for communication and control. ○​ Consists of neurons (nerve cells) and supporting cells. ○​ Found in the brain, spinal cord, and peripheral nerves. Plant Meristematic tissue is a type of plant tissue found in regions of growth, like the tips of roots and shoots. It's made up of cells that divide continuously, enabling plants to grow in length or girth. 1.​ Meristematic: For growth. 2.​ Permanent: Differentiated cells with specific functions. 3.​ Secretory: Produces substances like resins or oils. Elliptical tissue protects and secretion connective tissue supports and binds other tissues muscle tissue is used for movement nervous tissue is used for Signal transmission 1.​ Circulatory and Respiratory: Deliver oxygen and remove carbon dioxide. 2.​ Digestive and Circulatory: Absorb nutrients and transport them. 3.​ Musculoskeletal and Nervous: Enable movement. 4.​ Endocrine and Nervous: Regulate body functions with hormones and signals. 5.​ Immune and Integumentary: Defend against pathogens. 6.​ Excretory and Circulatory: Eliminate waste products. Body systems 1.​ Circulatory System: ○​ Function: Transports blood, nutrients, oxygen, carbon dioxide, and hormones throughout the body. ○​ Key Components: Heart, blood vessels (arteries, veins, capillaries), and blood. 2.​ Respiratory System: ○​ Function: Provides oxygen to the blood and removes carbon dioxide. ○​ Key Components: Lungs, trachea, bronchi, and diaphragm. 3.​ Digestive System: ○​ Function: Breaks down food into nutrients that can be absorbed into the bloodstream, and eliminates waste. ○​ Key Components: Mouth, esophagus, stomach, intestines, liver, pancreas, and gallbladder. 4.​ Musculoskeletal System: ○​ Function: Provides structure, support, and movement to the body. ○​ Key Components: Bones, muscles, tendons, ligaments, and joints. 5.​ Nervous System: ○​ Function: Controls and coordinates body activities by transmitting signals between different parts of the body. ○​ Key Components: Brain, spinal cord, nerves, and sensory organs. 6.​ Endocrine System: ○​ Function: Regulates body functions through the release of hormones. ○​ Key Components: Glands such as the thyroid, pituitary, adrenal, and pancreas. 7.​ Immune System: ○​ Function: Protects the body from infections and diseases.  ○​ Key Components: White blood cells, lymph nodes, spleen, and thymus. 8.​ Integumentary System: ○​ Function: Protects the body from external damage, regulates temperature, and provides sensory information. ○​ Key Components: Skin, hair, nails, and sweat glands. 9.​ Excretory System: ○​ Function: Eliminates waste products from the body and regulates water and electrolyte balance. ○​ Key Components: Kidneys, ureters, bladder, and urethra. 10.​Reproductive System: ○​ Function: Produces gametes (sperm and eggs) and facilitates reproduction. ○​ Key Components: In males: testes, penis. In females: ovaries, fallopian tubes, uterus, and vagina. Types of muscle tissue Skeletal Muscle: ​ Function: Responsible for voluntary movements, such as walking, lifting, and speaking. ​ Characteristics: Striated (striped appearance) and multinucleated (having multiple nuclei). ​ Location: Attached to bones by tendons. Cardiac Muscle: ​ Function: Contracts to pump blood throughout the body. ​ Characteristics: Striated, branched, and has a single nucleus per cell. Contains intercalated discs that connect cells and allow for synchronized contractions. ​ Location: Found only in the heart. Smooth Muscle: ​ Function: Controls involuntary movements, such as those in the digestive system, blood vessels, and airways. ​ Characteristics: Non-striated and has a single nucleus per cell. ​ Location: Found in the walls of internal organs like the stomach, intestines, and blood vessels. Smooth muscle tissue, unlike skeletal muscle, operates without conscious control. It's found in the walls of hollow organs like the stomach, intestines, and blood vessels. These muscles contract to move substances through the body, like food in the digestive system Stomata are small openings found on the surface of leaves and stems in plants. They play a crucial role in gas exchange, allowing the plant to take in carbon dioxide and release oxygen. Stomata can open and close to regulate the amount of gas exchange and water loss through transpiration. Plant cell Xylem and phloem are essential components of a plant's vascular system, responsible for the transport of water, nutrients, and food. Xylem: ​ Function: Transports water and dissolved minerals from the roots to the rest of the plant. ​ Components: Tracheids and vessel elements (long, tube-like structures). ​ Additional Role: Provides structural support to the plant. Phloem: ​ Function: Transports organic nutrients, particularly sucrose, from the leaves (where they are produced during photosynthesis) to other parts of the plant. ​ Components: Sieve tube elements and companion cells.