BIOLOGY REVIEWER MA’AM CATHLEEN PINEDA - BIOLOGY 1ST QUARTER 1 S.Y. 2022-2023 AIONA BLESSIE C. SALERES 12- STEM EINSTEIN • • INTRODUCTION TO BIOLOGY • WHAT IS BIOLOGY? • Bio = life ology =study of DIVISIONS OF BIOLOGY • • • • • • Botany: Study of Plants Zoology: Study of Animals Microbiology: Study of small organisms Genetics: Study of heredity Evolution: Study of change over time Ecology: Study of organisms and their environments BRANCHES OF BIOLOGY • • • • • • • • • • • • • • • Anatomy (internal structure) Cytology (cells) Histology (tissues) Biochemistry (biological reactions) Physiology (internal function) Genetics (heredity) Embryology (development) Biotechnology (genetic engineering) Parasitology (parasites) Taxonomy (classification) Ethology (behavior) Immunology (immunity) Ecology (environment) Pathology (disease) And so many more!!!!!! WHY STUDY BIOLOGY? • • Studying biology gives you the skills and opportunities to advance human knowledge and understanding in today's world, in order to make a difference to tomorrow's world. As humans, we need to understand our relationship to and how we impact other living organisms in our environment. L1: MICROSCOPY AND THE DISCOVERY OF CELLS WHAT ARE CELLS? • are the basic units of the structure and function of living things the smallest units that can carry out the processes of life the composition of organism DISCOVERY OF CELLS • Hooke was one of the earliest scientists to study living things under a microscope. • When he looked at a thin slice of cork under his microscope, he was surprised to see what looked like a honeycomb. • The cork was made up of many tiny units and Hooke called these units cells because they resembled cells in a monastery. • Anton van Leeuwenhoek in Holland made other important discoveries using a microscope. • Leeuwenhoek made his own microscope lenses and his microscope was more powerful than other microscopes of his day. • Leeuwenhoek was the first person to observe human cells and bacteria. CELL THEORY • • Two German scientists named Theodor Schwann and Matthias Jakob Schleiden proposed cells as the basic building blocks of all living things in early 1800s. Around 1850, a German doctor named Rudolf Virchow was studying cells under a microscope, when he happened to see them dividing and forming new cells. He realized that living cells produce new cells through division. Based on this realization, Virchow proposed that living cells arise only from other living cells. The ideas of all three scientists-Schwann, Schleiden, and Virchow-led to cell theory, which is one of the fundamental theories unifying all of biology. Cell theory states that: 1. All organisms are made of one or more cells. (Theodor Schwann and Matthias Jakob Schleiden) 2. Cells are the basic building blocks of life. (Theodor Schwann and Matthias Jakob Schleiden) BIOLOGY REVIEWER MA’AM CATHLEEN PINEDA - BIOLOGY 1ST QUARTER 1 S.Y. 2022-2023 AIONA BLESSIE C. SALERES 12- STEM EINSTEIN 3. All cells come from existing cells. (Rudolf Virchow) SEEING INSIDE CELLS • • • In the 1950s a new type of microscope was invented and it is called the electron microscope. It used a beam of electrons instead of light to observe extremely small objects. With the electron microscope, many more cell discoveries were made. SUMMARY • STRUCTURED SHARED BY ALL CELLS 1. The plasma membrane (a type of cell membrane) is a thin coat of lipids that surrounds a cell. It forms the physical boundary between the cell and its environment. You can think of it as the "skin" of the cell. 2. Cytoplasm refers to all of the cellular material inside of the plasma membrane. Cytoplasm is made up of a watery substance called cytosol, and it contains other cell structures, such as ribosomes. 3. Ribosomes are the structures in the cytoplasm in which proteins are made. 4. DNA (deoxyribonucleic acid) is a nucleic acid found in cells. It contains the genetic instructions that cells need to make proteins. • • • • Earth has a common ancestor in the distant past. Cells are the basic units of structure and function in living things. In the 1600s, Hooke was the first to observe cells from an organism (cork). Soon after, microscopist van Leeuwenhoek observed many other living cells. In the early 1800s, Schwann and Schleiden theorized that cells are the basic building blocks of all living things. Around 1850, Virchow observed cells dividing. To previous learnings, he added that living cells arise only from other living cells. These ideas led to cell theory, which states that all organisms are made of cells, that all life functions occur in cells, and that all cells come from other cells. It wasn't until the 1950s that scientists could see what was inside the cell. The invention of the electron microscope allowed them to see organelles and other structures smaller than cells. There is variation in cells, but all cells have a plasma membrane, cytoplasm, ribosomes, and DNA. These similarities show that all life on. L2: CELL STRUCTURES AND FUNCTIONS DEFINITION OF CELL • These for parts are common to all cells, from organisms as different as bacteria and human beings. • • The structural and functional unit of living body. The smallest organized unit of the living body which is independent and selfreproducing under favorable condition (De Robertis and De Robertis, 1981). It is a unit of biological activity delimited by a semi-permeable membrane and capable of self reproduction in a medium BIOLOGY REVIEWER MA’AM CATHLEEN PINEDA - BIOLOGY 1ST QUARTER 1 S.Y. 2022-2023 AIONA BLESSIE C. SALERES 12- STEM EINSTEIN • free of other living system (Loewy and Sikevitz, 1969). The cell is the basic unit in which matter energy are acquired, converted, stored, utilized and also in which biological information is stored, manipulated and expressed (Swanson and Webster, 1978). NUMBER OF CELL • The number of cell varies in the living organisms. The unicellular organisms like bacteria, amoeba, diatoms, Euglena etc. contain single cell in their body but most of the plants and animals are multicellular organisms which contain many cell in their body. SHAPE OF THE CELL • • • Generally, the animal cell is spherical in shape, but it may be elongated, cylindrical, oval, rounded, triangular, cuboidal, polygonal or irregular in different plants and animals. The shape of the cell remains correlated with its functions. The external and internal environment of the organism may also cause shape variations in the cell due to internal or mechanical stress or pressure and surface tension. SIZE OF THE CELL • • Generally, size of the cell varies from 1175000 μm. Among the living organisms, the smallest cell is mycoplasma bacteria which are 0.1 - 0.25 µm in diameter while the biggest cell is ostrich egg (170 x135 mm). The longest cell is the neuron cell which is about a meter or more in length. TYPES OF CELL 1. PROKARYOTIC CELL - This type cell is lack of nuclear envelop and well defined cytoplasmic organelles such as endoplasmic reticulum (ER), Golgi body, Mitochondria, centriole etc. Example of eukaryotic cells: Bacteria, blue green algae etc. 2. EUKARYOTIC CELL - The eukaryotic cell has the nucleus with a definite nuclear membrane. This type of cell also contains cytoplasmic organelles like endoplasmic reticulum, Golgi bodies, mitochondria, lysosomes, etc. MOST IMPORTANT CHARACTERISTICS OF PROKARYOTIC CELLS • • • • The prokaryotic cells are unicellular and filamentous like form which is not exceeding 10 um in diameter. They have a more or less rigid cell wall and a jelly like mucilaginous capsule or sheath outside the plasma membrane. This cell does not contain nucleus due to absence of nuclear envelop. This type of cell also contain single naked chromosome with naked DNA. CHARACTERISTIC FEATURES OF EUKARYOTIC CELL • • • It is generally large in size, but only few cells being under 10 µm in diameter. The cell is bounded by the plasma membrane in the animal cell but in the plant cell, it is bounded by the cell wall which is made up of cellulose. This type of cell contains true nucleus which bears nucleoplasm, nucleolus, RNA DNA, chromosomes and nuclear membrane. CELL STRUCTURE AND THEIR FUNCTIONS The eukaryotic cells have different shapes, sizes and physiology but all the cells are typically composed of: 1. CELL-COVERING - has two parts such as plasma membrane and cell wall. - Most of the cells are enclosed by a thin porous semi permeable membrane which is known as plasma membrane. - The cell wall is present only in the plant cell. - Plasma membrane is a permeable membrane by which extracellular substances entered into the cell while the cell wall provides protection and BIOLOGY REVIEWER MA’AM CATHLEEN PINEDA - BIOLOGY 1ST QUARTER 1 S.Y. 2022-2023 AIONA BLESSIE C. SALERES 12- STEM EINSTEIN support to the plasma membrane and cytoplasm. 2. CYTOPLASM - The substance which occurs between the plasma membrane and nuclear membrane is called cytoplasm. - They carry out the instructions sent from the nucleus. - They also provide sites for cellular activities. 3. CYTOPLASMIC ORGANELLES - Generally, they perform various important biosynthetic and metabolic activities such as transportation, support, storage, reproduction, respiration etc. blood cells. When red blood cells sickle, they break down prematurely, which can lead to anemia. Anemia can cause shortness of breath, fatigue, and delayed growth and development in children. The rapid breakdown of red blood cells may also cause yellowing of the eyes and skin, which are signs of jaundice. Painful episodes can occur when sickled red blood cells, which are stiff and inflexible, get stuck in small blood vessels. These episodes deprive tissues and organs, such as the lungs, kidneys, spleen, and brain, of oxygen-rich blood and can lead to organ damage. L3: CELL STRUCTURES AND FUNCTIONS CYTOPLASMIC ORGANELLES 4. NUCLEUS - They act as a brain for the cell. - They synthesize RNA, ribosome and ribosomal protein. - Nuclear membrane makes partitions between nucleus and cytoplasm. - They regulate the cellular process and bear the hereditary instructions. SICKLE CELL DISEASE • • People who have sickle cell disease have abnormal hemoglobin genes. This causes their red blood cells to assume a sickle shape. Sickle-shaped red blood cells are not flexible, and thus, they stick to vessel walls resulting in abnormal blood flow. This then impedes the delivery of oxygen to the tissues, greatly affecting the health of patients. is a group of disorders that affects hemoglobin, the molecule in red blood cells that delivers oxygen to cells throughout the body. People with this disease have a typical hemoglobin molecules called hemoglobin S, which can distort red blood cells into a sickle, or crescent, shape. SIGNS AND SYMPTOMS • The signs and symptoms of sickle cell disease are caused by the sickling of red The eukaryotic cell contains the following organelles: 1. GOLGI BODY - It is a very important organelle of the cell and is covered by a single smooth membrane of lipoprotein. It consists of cisternae, vesicles and vacuoles. - It plays an important role for the transportation of materials within the cell. It forms secretary vesicles and lysosomes. They also form cell wall of the plat cell and plasma membrane. 2. ENDOPLASMIC RETICULUM (ER) - They are inter-connecting tubules and vesicles which are bounded by a single unit membrane. Rough ER is called rough because it has ribosomes attached to its surface. Smooth ER (SER) acts as a storage organelle. - They maintain intracellular circulatory system. They act as synthetic and storage organs. They provide mechanical support to the cell by making cytoplasmic frame work. 3. LYSOSOMES - It is found only in the animal cell and it is a tiny spheroid particles which consist of hydrolytic enzyme. They are enclosed within the single lipoprotein membrane. BIOLOGY REVIEWER MA’AM CATHLEEN PINEDA - BIOLOGY 1ST QUARTER 1 S.Y. 2022-2023 AIONA BLESSIE C. SALERES 12- STEM EINSTEIN They mainly take part in the intracellular digestion of food materials within the cell by the process of pinocytosis and phagocytosis. • 4. RIBOSOMES - They are minute spherical nonmembranous structures which consist of RNA and protein. - They provide sites for protein synthesis. • 5. MITOCHONDRIA - It is filamentous or granular hollow type structure which is bounded by a double lipoprotein membrane. - They are called power house of the body because they produce energy as ATP through Kreb's cycle, electron transport chain, betoxidation of fatty acids etc. • - 6. CHLOROPLASTS - It is a disc shaped chlorophyll containing organelle which is bounded by double membrane. It is only present in the plant cell. - They act as a storage for starch, pigments for photosynthesis. They help in the biosynthesis of food stuffs by the process of photosynthesis. 7. CENTROSOMES - It is present only animal cell. It contains dense cytoplasm which is placed near the nucleus of the cell. - It forms the spindle during the cell division and help in the movement of chromosomes. • • • • The sperm cell is another specialized cell with parts that fit its function. Sperm cells have a tail, the flagellum, which propels it toward the egg cell for fertilization. It has plenty of mitochondria. L3: CELLULAR TRANSPORT PASSIVE TRANSPORT a movement of substances across the membranes without energy expenditure. PASSIVE TRANSPORT: DIFFUSION • unassisted movement from higher concentration to lower concentration area. PASSIVE TRANSPORT: FACILITATED DIFFUSION • - movement of substance requires a protein channel and a carrier protein. CHANNEL PROTEIN - opens or close as they respond to a stimuli. CARRIER PROTEIN - change in shape, triggered by the binding and release of a substance it transports. PASSIVE TRANSPORT: OSMOSIS Cell specialization has contributed greatly to the adaptation of organisms. Specialized cellular modifications are alterations in cells that distinguish them from one another. Example, cells that absorb nutrients in the small intestine have microvilli. These are extensions on the cell membranes that help increase the surface area of the cell, thus, facilitating increased absorption of nutrients. • diffusion of water molecules across a selectively permeable membrane. HYPERTONIC - higher concentrated region. HYPOTONIC - lower concentrated region. ISOTONIC - concentration is equal. ACTIVE TRANSPORT • requires the expenditure of energy and utilizes Adenosine Triphosphate (ATP). BIOLOGY REVIEWER MA’AM CATHLEEN PINEDA - BIOLOGY 1ST QUARTER 1 S.Y. 2022-2023 AIONA BLESSIE C. SALERES 12- STEM EINSTEIN • the movement for active transport across membranes is unidirectional. TYPES OF EPITHELIAL TISSUES (Structure) • BULK TRANSPORT • movement of large molecules in and out of the cell. • SIMPLE EPITHELIUM - made up of only one layer of cells and according to cell shape (squamous, cuboidal or columnar) STRATIFIED EPITHELIUM - more than one layer of cells, according to the shape of its top-most layer (squamous, cuboidal, columnar, transitional or pseudostarified) CONNECTIVE TISSUES • • • EXOCYTOSIS – process of removing materials from the cell. ENDOCYTOSIS – cells engulf material. • • TENDONS usually bind a muscle to bone, while LIGAMENTS connect bone to another bone Most common types includes: areolar tissue, fibrous tissue, adipose tissue, bone, cartilage and blood BLOOD is considered as a supportive tissue since its primary function is to supply the body with nutrients and gases it needs TYPES OF CONNECTIVE TISSUES L4: ANIMAL AND PLANT TISSUES EPITHELIAL TISSUES • • • • consists of sheets of cells that cover organisms and their organs. also form glands that synthesize secretory products for discharge onto their environment can vary in shape: SQUAMOUS, COLUMNAR, CUBOIDAL or CILIATED cell-to-cell junctions are called TIGHT JUNCTIONS: seal off a tissue from adjacent open spaces and prevent the entrance of disease causing microorganisms. 1. COLLAGENOUS CONNECTIVE TISSUE made up of Type I collagen, a loose connective tissue in the fasciae. Dense regular connective tissues in periosteum 2. RETICULAR CONNECTIVE TISSUE formed by Type III collagen. Commonly found as a supporting framework of hematopoietic and lymphoid organs. It also a protein found in bones and cartilage 3. ELASTIC CONNECTIVE TISSUE - formed by Type II collagen; a component of joint cartilage, contains retractile fibers with elastin. It is not easily visualized under the microscope unless it is stained. MUSCULAR TISSUES it can be grouped into two: • Can be classified according to: 1. number of cell layers (simple or stratified) 2. shape of layers (squamous, cuboidal or columnar) 3. surface specialization (cilia, keratin, goblet cell or brush border) • VOLUNTARY MUSCLES - can be controlled by the nervous system. INVOLUNTARY MUSCLES - beyond the control of the nervous system TYPES OF MUSCULAR TISSUES 1. SKELETAL MUSCLES - very long, cylindrical, multi-nucleated cells capable of BIOLOGY REVIEWER MA’AM CATHLEEN PINEDA - BIOLOGY 1ST QUARTER 1 S.Y. 2022-2023 AIONA BLESSIE C. SALERES 12- STEM EINSTEIN quick and forceful contractions that are usually voluntary 2. CARDIAC MUSCLES - elongated branched individual cells that are configured parallel to each other 3. SMOOTH MUSCLES - collection of cells that do not show cross-striations; largest at their midpoint and taper toward their ends. Their contraction process is slow and not subject to voluntary control. CLASSIFICATION OF PLANTS BASED ON ORIGIN 1. NERVOUS TISSUES • • • specialized for the reception and conduction of impulses usually found in the brain and spinal cord neurons or nerve cells: individual cells of the brain and spinal cord CLASSIFICATION OF MERISTEMATIC TISSUE A. APICAL MERISTEM - It is present at the growing tips of stems and roots and increases the length of the stem and root. They form growing parts at the apices of roots and stems and are responsible for the increase in length, also called primary growth. This meristem is responsible for the linear growth of an organ. B. LATERAL MERISTEM - This meristem consists of cells which mainly divide in one plane and cause the organ to increase in diameter and girth. Lateral meristem usually occurs beneath the bark of the tree in the form of Cork Cambium and in vascular bundles of dicots in the form of vascular cambium. The activity of this cambium results in the formation of secondary growth. C. INTERCALARY MERISTEM - This meristem is located in between permanent tissues. It is usually present at the base of the node, internode and on leaf base. They are responsible for growth in length of the plant and increasing the size of the internode. They result in branch formation and growth. TYPES OF NEURONS 1. SENSORY NEURONS - carry information obtained from the interior of the body and the environment to the CNs 2. MOTOR NEURONS - carry impulses from the CNS to the effector organs commanded by these centers. PLANT TISSUES • • Tissue is a cellular organizational level between cells and a complete organ. A tissue is an ensemble of similar cells and their extracellular matrix from the same origin that together carry out a specific function. Tissues are categorized broadly into three tissue systems: 1. EPIDERMIS – cells forming the outer surface of the leaves and of the young plant body. 2. VASCULAR TISSUE – The primary components of vascular tissue are the xylem and phloem. These transport fluids and nutrients internally. 3. GROUND TISSUE – Ground tissue is less differentiated than other tissues. It manufactures nutrients by photosynthesis and stores reserve nutrients. MERISTEMATIC TISSUE • It consists of actively dividing cells and leads to increase in length and thickness of the plant. • The primary growth of a plant occurs only in certain, specific regions, such as in the tips of stems or roots. • It is in these regions that meristematic tissues are present. Cells in these tissues are roughly spherical or polyhedral, to rectangular in shape, and have thin cell walls. 2. PERMANENT TISSUES • Defined as a group of living or dead cells formed by meristematic tissue and have lost their ability to divide and have permanently placed at fixed positions in the plant body. BIOLOGY REVIEWER MA’AM CATHLEEN PINEDA - BIOLOGY 1ST QUARTER 1 S.Y. 2022-2023 AIONA BLESSIE C. SALERES 12- STEM EINSTEIN THREE TYPES OF PERMANENT TISSUES A. SIMPLE PERMANENT TISSUES (THREE TYPES OF SIMPLE PERMANENT TISSUE) 1. PARENCHYMA • This tissue provides support to plants and also stores food. • It is a special type of parenchyma that contains chlorophyll and performs photosynthesis. 2. COLLENCHYMA • This tissue gives tensile strength to the plant and the cells are compactly arranged and have very little intercellular spaces. • Collenchyma tissue acts as a supporting tissue in stems of young plants. • It provides mechanical support, elasticity, and tensile strength to the plant body. • It helps in manufacturing sugar and storing it as starch. • It is present in the margin of leaves and resists tearing effect of the wind. B. COMPLEX PERMANENT TISSUES (TWO TYPES OF COMPLEX PERMANENT TISSUE) • • • • • 1. XYLEM Xylem serves as a chief conducting tissue of vascular plants. It is responsible for the conduction of water and mineral ions/salt. Xylem tissue is organized in a tube-like fashion along the main axes of stems and roots. 2. PHLOEM Phloem is an equally important plant tissue as it also is part of the ‘plumbing system’ of a plant. Phloem carries dissolved food substances throughout the plant. Phloem transports food and materials in plants upwards and downwards as required. C. SPECIAL OR SECRETORY TISSUES (GRANDULAR)
