General Biology 2: Lesson 1 - Animal and Plant Specialized Structures PDF

# GENERAL BIOLOGY 2 ## LESSON 1: Animals and Plants' Specialized Structures ### Animals' Specialized Structures **Cells → Tissues** - Tissues are formed as a result of cell differentiation. - The human body is composed of more than 200 differentiated cells. - **Histology** - the study of animal...

# GENERAL BIOLOGY 2 ## LESSON 1: Animals and Plants' Specialized Structures ### Animals' Specialized Structures **Cells → Tissues** - Tissues are formed as a result of cell differentiation. - The human body is composed of more than 200 differentiated cells. - **Histology** - the study of animal and plant tissues. - 4 types of tissues found in animals: epithelial, connective, muscular, and nervous. ### EPITHELIAL TISSUES Epithelial tissue can be simple or stratified. - **Simple Epithelium** - is made up of single layer cells. - **Stratified Epithelium** - has more than one layer of cells. Three types of epithelium are squamous, cuboidal, and columnar. ### CONNECTIVE TISSUES This includes large **extracellular space** called **extracellular matrix**. - **Extracellular matrix** may be solid (bone), soft (connective tissue), or liquid (blood). Main function of connective tissue is to bind and support other tissues. Classified into 3 large groups: connective tissue proper, supportive connective tissue, and fluid connective tissue. 1. **Connective Tissue** - composed of loose and dense, reticular elastic, and adipose connective tissue. - **Loose connective tissue** - is also called areolar connective tissues has a watery matrix (ground substances) where its cells, mostly fibroblasts are located. - **Dense connective tissues** - are made up of closely packed bundles of collagen fibers with few cells. - **Reticular connective tissue** - are made up of cells called reticulocytes and a matrix that contains reticular fibers. - It gives support to soft organs such as the spleen, lymph nodes and liver. - **Elastic connective tissues** - are highly elastic (flexible), with flattened fibroblast cells with a matrix that contains bundle of elastic fibers and interspersed collagen fibers. - **Adipose tissues** - a special type of connective tissues that store fats. 2. **Supportive connective tissue** - are composed of cartilage and bones. - **Cartilage** - is a type of connective tissue with cells called chondrocytes, which are separated by a strong yet flexible matrix made up of a substance called chrondrin, a **protein-carbohydrate complex**. - **Bones** - are hardened connective tissues containing cells called osteocytes, a matrix with collagen fibers and mineral deposits. 3. **Fluid connective tissue** - is composed of blood. - **Blood** - is a special type of connective tissue with a liquid matrix called the blood plasma. - The cells in the blood include the **erythrocytes** or the red blood cells (transports oxygen), the **leukocytes** or white blood cells (for body's defense), and the **thrombocytes** or blood platelets. ### MUSCULAR TISSUES - are contractile tissues responsible for movement. - it contains muscle cells called muscle fibers. 3 types of muscular tissues: skeletal, cardiac and smooth. 1. **Skeletal muscular tissues** - are attached to bones through tendons and are responsible for locomotion. The contraction of skeletal muscles are under voluntary control. 2. **Cardiac muscular tissue** - are found only in the walls of the heart - the contraction of cardiac muscles causes the heart to beat which pumps blood. - Cardiac muscles contraction is involuntarily controlled. 3. **Smooth muscle tissues** - are found in the walls of the stomach, intestines, urinary bladder, uterus, and blood vessels. - Smooth muscles are spindled-shaped muscles that are involuntarily controlled. ### NERVOUS TISSUES - is made up of nerve cells called **neurons**, which are found in the brain and spinal cord. - a typical neuron is made up of three parts: dendrites, cell body, and axon. - **Dendrites** - receive impulses and send them to the cell body - **Cell body** - is like a typical cell where the nucleus and organelles are found. - **Axon** - is a long fiberlike part that transmits the impulses away from the cell body to the next neuron. ### Plants' Specialized Structures ## PLANT STRUCTURE Organs that allow a plant to grow are called **vegetative organs** (roots, stems and leaves). - **Roots** - anchors the plant to the soil for support and absorbs water and minerals from the soil. - **Stem** - is the main axis of the plant together with its branches. It distributes the products of photosynthesis to the other plant parts. - **Leaves ** - are responsible for the manufacture of food by photosynthesis. ## PLANT TISSUE Two main types of tissues in plants: **Meristematic** and **Permanent**. 1. **Meristematic Tissue** - a plant grows because of its **meristems**. - **Meristems**- are made up of embryonic tissues called meristematic tissues. - a part of plant where growth is fastest. 2. **Permanent tissues** - are further divided into 3 types namely: surface, fundamental and vascular. - **Surface Tissues** - also called **dermal tissues**. - cover and protect the surface of the different plant organs. - Ex. Epidermis of the leaf is an example of surface tissue. - **Fundamental Tissues ** - also known as ground tissues forms the main bulk of plants. - Fundamental tissues are made up of three types of cells: parenchyma, collenchyma, and sclerenchyma. - **Parenchyma** - are large, thin-walled, and usually have a large central vacuole responsible for food storage. - It is also capable of cell division. - **Collenchyma** - function mainly as support. - is very similar in structure to parenchyma cells except that they have a thicker cell wall, which explains their support function. - **Sclerenchyma** - have a thick secondary cell wall in addition to the primary cell wall. - The secondary cell wall is impregnated with lignin, an organic substances that makes the cell wall tough and hard. - **Vascular Tissue** - are complex conducting tissues that extend from the roots to the leaves of plants. - Two types of vascular tissues: **xylem** and **phloem** - **Xylem** - transports water and minerals from roots to leaves via the stem. - **Phloem** - transports organic nutrients or food in both directions along the length of the plant. - It is usually located outside the xylem. ## THANK YOU!