PLANT PARTS, BLOOD, TISSUE, MUSCLE

Monocot root

Here, the vascular tissues form a ring around the center of the root. Also, the pith is a centrally located ground tissue that functions in food storage.

Exercise #25 -- Animal Organization

Humans have the following levels of biological organization: cells --> tissues --> organs --> organ systems Tissues are groups of cells that have the same structural characteristics and perform the same function. Organs are composed of different types of tissues. Organ systems are composed of various organs. There are 4 major types of tissues in the human body (see Figure 25.1): epithelial, connective, muscle, and nervous.

Muscular Tissue

The human body contains 3 types of muscular tissue: skeletal, cardiac, and smooth.

Stomata and their Role in Transport of Water

The opening and closing of stomates on the lower epidermis of leaves is controlled by guard cells. When the stomates are open for gas exchange, water evaporates from the leaves. The more stomates present in a leaf, the greater water loss there will be due to transpiration.

Simple Cuboidal Epithelium

contains a single layer of cube-shaped cells that are found in the tubules of kidneys, and in the ducts of many glands where it functions in secretion and absorption.

Stratified Squamous Epithelium

contains many layers of flat cells that make up the epidermis of the skin, linings of mouth, throat, anal canal and vagina.

Compact Bone

located in the bones that make up the skeleton and consists of the following: osteons (i.e., Haversian system), central canal (i.e., Haversian canal -- contains a nerve and blood vessels that service the bone), lamella (i.e., concentric rings) with lacunae (i.e., concentric rings of spaces that contain osteocytes -- bone cells), and canaliculi (i.e., extensions of cytoplasm from the osteocytes that connect the lacunae). The matrix that separates the lacunae is hard due to presence of calcium.

Smooth Muscle

makes up the walls of internal organs such as blood vessels and intestines; undergoes involuntary contraction since it doesn't require conscious effort; contains spindle-shaped cells with no striations and only one nucleus.

Loose Fibrous Connective Tissue

located between muscles, beneath skin and beneath most epithelium

Development of Dicot Embryo

A plant embryo consists of the following 3 parts: the epicotyl (i.e., becomes the leaves), the hypocotyl (i.e., becomes the stem), and the radicle (i.e., becomes the roots). In addition, the cotyledons will store nutrients that the embryo uses as nourishment

Nervous Tissue

Nervous tissue is found in the brain, spinal cord, and nerves and is composed of 2 types of cells: neurons (i.e., transmit nerve impulses) and neuroglia (i.e., service the neurons). Motor neurons (i.e., send messages from the spinal cord to the muscles) are composed of 3 parts: dendrites (i.e., receives nerve impulse), cell body (i.e., contains nucleus), and axon (i.e., takes nerve impulse away from cell body).

Roots

Root hairs aid in the absorption of water and nutrients from the soil. They increase the surface area available for absorption, thus making it more efficient. Roots also have several tissues, such as an epidermis, cortex, xylem and phloem, The root cap is made up of dead cells at the tip of the root which provides protection as the root grows.

Kinds of fruits

Simple fruits (i.e., derived from a single ovary) -- classification based upon texture of the ovary wall a. Simple Fleshy fruits 1) Drupe -- endocarp is a hard pit; Ex. peach, plum 2) Berry -- exocarp is a skinlike cover with numerous small seeds inside; Ex. tomato 3) Pome -- contains accessory tissue; Ex. apple, pear 4) Pepo -- exocarp is rind; Ex. cucumber 5) Hesperidium -- exocarp is a leathery rind; Ex. orange b. Simple Dry Fruits (i.e., pericarp is dry) 1) Dry Dehiscent - fruit splits open at maturity and the seed is ejected out of the fruit; Ex. green beans, peanuts, peas 2) Dry Indehiscent - fruit doesn't split open at maturity and the seed remains "in" the fruit; Ex. oats, acorns, sunflowers 2. Aggregate fruits (i.e., develop from a number of ovaries within a single flower) -- Ex. strawberries, raspberries 3. Multiple fruits (i.e., develop from a number of ovaries of several flowers) -- Ex. pineapples, figs

Stems

Stems serve as a connection between roots and leaves and reproductive organs. Stems can also be a site for food storage. The arrangement of vascular tissues in stems varies between monocots and herbaceous (non-woody) dicots and woody dicots.

Stem Diversity

Stolons -- aboveground horizontal stems; Ex. strawberry plant Rhizomes -- belowground horizontal stems that can give off food storage tubers (i.e., potato); Ex. iris plant Corms -- belowground vertical stems that have thin, papery leaves; Ex. gladioloa plant Bulbs -- belowground, very short vertical stems that are surrounded by thick fleshy leaves; Ex. onion plant

Fruits

As an ovary develops into a fruit, the ovarian wall thickens and becomes the pericarp with 3 layers: 1. Exocarp -- outermost layer of the fruit wall 2. Mesocarp -- middle layer of the fruit wall 3. Endocarp -- innermost layer of the fruit wall

Leaves

The surfaces of the leaf are covered by an epidermis, which is coated by a waxy cuticle. The cuticle protects the leaf from water loss. To allow for gas exchange, there are tiny openings called stomata. These stomata are surrounded by guard cells. The guard cells open and close the stomata to regulate gas exchange For the most part, stomata are only found in the lower (i.e. the underside of the leaf) epidermis. Inside the leaf, we find the mesophyll sandwiched between the upper epidermis and lower epidermis. The mesophyll is composed of palisade cells and spongy cells. The palisade cells are tightly compacted cells that contain chlorophyll. Therefore, the bulk of photosynthesis for the plant occurs in the palisade mesophyll. The spongy cells are loosely compacted cells that facilitate the movement of gases. Notice that there is a vein present, and that it shows the presence of xylem and phloem.

Connective Tissue

Connective tissue functions to join different parts of the body together. All connective tissue consists of cells surrounded by a matrix of fibers such as elastic fibers (i.e., composed of a protein called elastin) and collagenous fibers (i.e., composed of a protein called collagen). The types of connective tissue include: loose fibrous, dense fibrous, adipose, bone, cartilage, and blood

Tissue Level of Organization

Epithelial tissue forms a continuous sheet over the entire body surface and most of the body's inner cavities. It has numerous functions including protection, production and release of secretions, and nutrient absorption. The classification of epithelial tissue is based upon: 1) the shape of the cells and 2) the number of layers. There are 3 epithelial cell shapes: squamous, cuboidal, and columnar. There are 3 types of epithelial tissue layers: simple (i.e., only one layer of cells), stratified (i.e., cell layers are on top of each other), and pseudostratified (i.e., only appear to be layered). Some epithelial tissue may also have microvilli (i.e., cellular extensions) and cilia (i.e., hairlike extensions)

Exercise #21 -- Reproduction in Plants

Flowers are the reproductive organs of angiosperms. Angiosperm fertilization is preceded by pollination (i.e., the transfer of pollen from the male anther to the female carpel. After the egg is fertilized by the sperm within the ovary of the carpel, a fruit develops which aids in the dispersal of angiosperm seeds (i.e., contains an embryonic plant)

Intestinal Wall

The wall of the intestines is composed of 4 layers: mucosa (i.e., lines the central cavity and is composed of folds called villi that increase absorption of food), submucosa (i.e., contains nerve fibers, blood vessels, and lymphatic vessels; products of digestion absorbed into the blood and lymphatic vessels), muscularis (i.e., contains circular and longitudinal muscles that undergo rhythmic contractions called peristalsis that moves the food through the intestines), and serosa (i.e., thin layer that is part of the peritoneum -- lines the entire abdominal cavity).

Root Diversity

There are basically two types of roots: taproots and fibrous roots. Taproots usually have one major root from which other roots branch. They are usually found in dicots. Fibrous roots lack a major root, instead the roots form several branches that are similar in size. Monocots usually employ a fibrous root system. As opposed to taproots, which are capable of penetrating deep into the soil, fibrous roots are more spread out over a larger area.

Blood

a connective tissue in which the matrix is an intercellular fluid called plasma which contains red blood cells (i.e., erythrocytes which transport oxygen) and white blood cells (i.e., leukocytes that fight infection).

Pseudostratified Ciliated Columnar Epithelium

appears to be layered but all the cells touch the basement membrane; found lining the human trachea and also the linings of the reproductive system tubes; functions in moving mucus and debri back into the throat so it doesn't enter the lungs and also in movement of mucus and sex cells in the reproductive tract.

Simple Columnar Epithelium

contains a single layer of tall, column-shaped cells that have a nucleus near the base of the cell and can be found lining the digestive tract and functions in protection, secretion, and absorption. This tissue also contains goblet cells that secretes mucus into the gut cavity to protect it from digestive enzymes.

Simple Squamous Epithelium

contains single layer of flat cells that lines internal cavities, the heart, blood vessels, and air sacs of lungs and functions in filtration, diffusion, and osmosis.

Adipose Tissue

found beneath the skin, around the heart and kidneys; functions in insulation, fat storage, and cushioning; contains cells that have a large central vacuole that is filled with fat.

Dense Fibrous Connective Tissue

found in tendons (i.e., connects muscle to bones) and ligaments (i.e., connects bones to other bones at joints) and is composed of many collagenous fibers packed together.

Cardiac Muscle

found only in the heart; undergoes involuntary control; contains branched, striated cells that are bound together by intercalated disks and have only one nucleus.

Hyaline Cartilage

located in the nose, ends of bones, between ribs and sternum; contains cells called chondrocytes that are located in lacunae which are separated by a flexible matrix composed of weak collagenous fibers

Skeletal Muscle

occurs in muscles attached to bones; undergoes voluntary contraction since it is under conscious control; contains unbranched striated muscle cells that have multiple nuclei all peripherally located.

For the lab practical, you should

1. Be able to identify the structures of a plant. 2. Make sure you can identify the differences between monocots and dicots. 3. Know the functions of roots, stems, and leaves. 4. Be able to identify the parts of a root tip. 5. Be able to identify the types of vascular tissues in the microscope slides. Know the functions of the vascular tissues. Based on the arrangement of vascular tissues in a root and a stem, be able to identify if it is a monocot or a dicot. 6. Make sure you know the structures of a woody stem and the difference between summer and springwood. Also, make sure you can determine the age of a woody stem. 7. Be able to identify the external structures of a winter twig. 8. Be able to identify the structures of a leaf and the different types of leaves. 1. Know the composition of xylem and phloem and which direction materials are moved through each. 2. Know the difference between isotonic, hypertonic, and hypotonic solutions and which direction water moves when a plant cell is placed into each. 3. Know the structures of the root responsible for absorbing water from the soil. 4. Know the process of transpiration and the role of environmental factors on the rate of transpiration and the role of the stomates in the transport of water 1. Be able to identify the flower parts and know their function. 2. Know the difference between a monocot and a dicot flower. 3. Know the flowering plant life cycle. 4. Know the 3 layers of a fruit and be able to identify the different types of fruits by their technical names. 5. Be able to identify the parts of a monocot and dicot seed and know what is necessary for seed germination to occur. 1. Be able to identify the 4 majors types of tissues and give an example of a location and function of each. 2. Be able to identify the 4 layers of the intestine. 3. Be able to identify the structures found in the human skin

Major Tissues of Roots, Stems, and Leaves

1. Dermal tissue -- contains the epidermal cells that make up the epidermis (i.e., outermost covering of nonwoody plants) which has specialized functions 2. Ground tissue -- contains parenchyma and sclerenchyma cells; makes up the bulk of plant and includes the cortex, pith, and mesophyll; functions in carrying out photosynthesis or storing the products of photosynthesis 3. Vascular tissue -- consists of xylem (i.e., transports water and minerals using dead, hollow cells called vessel elements and tracheids) and phloem (i.e., transports organic nutrients using sieve-tube members and companion cells) Angiosperms can be further divided into monocots and dicots (i.e., eudicots). Monocots include grasses, lilies, and palms. Dicots include most all flowering plants. Dicots can be herbaceous (non-woody) or woody. There are several structural differences between monocots and dicots. Refer to figure 18.4 for a comparison between monocots and dicots. In the seed: notice the number of cotyledons: 1 in the monocot and two in the dicot (this is where they get their names). In the leaves: notice that the dicot leaf has broad blade with a net-like vein pattern; monocot leaves have a long slender blade with a parallel vein pattern. Notice also that dicot leaves attach to the stem via a petiole, while monocot stems do not have a petiole. In the stems: dicot stems have a ring of vascular bundles near the periphery of the stem; monocot stems have vascular bundles scattered throughout In the roots: dicots utilize a taproot system that is able to penetrate deep into the soil; monocots utilize a fibrous root system that spreads out through the soil. In the flowers: dicots have floral parts present in multiples of four or five; monocots have floral parts present in multiples of three.

Life Cycle (see Figure 21.2) -- sporophyte (i.e., diploid stage) generation is dominant

1. Pollination occurs by transfer of pollen from the anther to the stigma via insects, birds, or bats 2. Pollen grain develops a pollen tube which begins growing down towards the ovule 3. Within the ovule: a. Megaspore mother cell undergoes meiosis to form four megaspores of which three degenerate b. Surviving megaspore undergoes mitosis three times to form the following 8 cells/nuclei: 1) One egg cell 2) Two synergid cells which surround the egg cell 3) Two polar cells 4) Three antipodal cells c. The ovule is surrounded by an integument which contains an opening at the base called the micropyle 4. The pollen tube enters through the micropyle into one of the two synergid cells a. The tip of the pollen tube degenerates and releases two sperm cells b. Double fertilization occurs in which the following occurs: 1) One sperm cell fertilizes the one egg cell to form the zygote 2) One sperm cell unites with the two polar cells to form a 3N endosperm (i.e., provides food for the embryo within the seed) 5. Ovule matures to form a seed and the ovary matures to form the fruit which protects the seeds within it (i.e., covered seed)

Parts of the flower

1. Receptacle - supports the flower 2. Sepals - green, leaf-like structures which protect the flower bud and collectively are called the calyx 3. Petals - brightly-colored and often scented to attract pollinators and are collectively called the corolla 4. Stamens - male reproductive organs that are made up of the following: a. Filament - stalk that supports the anther b. Anther - contains two pollen sacs where microspores develop into pollen grains 5. Carpel - female reproductive organ that contains the following: a. Stigma - sticky terminus that adheres pollen grains b. Style - stalk c. Ovary - enlarged base that develops into the fruit and contains the ovules that become seeds after fertilization

Leaf Diversity

The blade, a thin, broad structure, is the major part of the leaf. In dicots, the blade is attached to the stem by a leaf stalk called the petiole. Monocot leaves lack a petiole and are attached directly to the stem. Furthermore, dicot leaves have a broad blade and monocot leaves have a slender blade. The vein patterns of leaves are different depending upon whether or not it is a monocot or a dicot. Monocot leaves exhibit parallel venation. Dicot leaves display net venation. The veins repeatedly branch from a midrib vein, which runs down the center of the leaf. The specific venation pattern can be either pinnate or palmate. Pinnate leaves are characterized by a single midrib vein that gives rise to several lateral branches. Palmate leaves are characterized by several major veins branching directly off the petiole. Both types of leaves can be compound, where the blade is divided into several leaflets, or simple. Figure 18.15 in the lab manual shows some examples of these different leaf types.

Dicot root

The cortex forms the bulk of the root from the epidermis to the endodermis and functions in food storage. stele, which contains the vascular tissues of a dicot root. It forms an "X" shape The cortex around the stele has starch cells containing starch granules (remember that the glucose produced during photosynthesis is stored as starch). Be sure to identify the following tissues: endodermis (the innermost layer of the cortex surrounding the stele), and the components of the stele (pericycle, phloem and xylem). Xylem and phloem are both vascular tissues. Xylem is large vessels composed of thick-walled cells. Phloem is composed of two types of cells: sieve tubes and companion cells

Transpiration Pull

The evaporation of water from openings called stomata in plant tissues is called transpiration. This process mostly occurs in the leaves. It is the process of transpiration that is responsible for the upward flow of water in the xylem. The rate of transpiration is affected by three factors: 1. Temperature -- increased temperatures causes increased rates of transpiration 2. Humidity -- increased humidity causes decreased rates of transpiration 3. Wind -- increased wind causes increased rates of transpiration

The Integumentary System:

The integumentary system includes the skin, hair and nails. Our discussion will focus primarily on the skin. Notice that the skin is composed of three layers (i.e., epidermis, dermis, and hypodermis. The epidermis is the outermost layer and is composed of mostly dead cells. This is an example of stratified squamous epithelium (remember this from epithelium section). These dead cells are imbedded in a meshwork of a protein called keratin. This protein provides a waterproofing layer covering the body. There are also melanocytes (i.e., produce skin's pigmentation). The dermis is the thickest part in the middle. The dermis contains many structures. The hair follicle secretes and grows hair. The arrector pili muscle is a smooth muscle that causes hair to stand upright when they contract. This contraction is what causes "goose bumps". The sebaceous gland is closely associated with the hair follicle, and secretes oil. The sweat gland secretes sweat, which is an essential function in maintaining a constant body temperature. There are capillaries (i.e., blood vessels) and a variety of nerve endings (i.e., sensory receptors). The hypodermis (i.e., subcutaneous layer) is the innermost layer of the skin. It usually has a layer of adipose tissue, which serves to insulate the inner tissues, and also nerves, arteries, and veins.

Exercise 19: Water Absorption and Transport in Plants

This exercise deals primarily with the vascular tissues. Remember, there are two types of vascular tissues: xylem and phloem. Xylem is responsible for transporting water and dissolved minerals. Xylem transport is always upward. Water forms a continuous column in the xylem for two reasons: 1. The molecules of water interact with one another because of hydrogen bonding between them and 2. Water adheres to the sides of the vessels because of its polar nature. Phloem is responsible for transporting the organic nutrients produced during photosynthesis. This transport process is referred to as translocation. Translocation through phloem can be either upward or downward. Xylem is composed of vessel cells or tracheids, depending on the type of plant. Study figure 19.1 and notice the tiny pores between adjacent cells of xylem. These pores allow lateral movement of minerals. When water is absorbed by root hairs, it moves in a lateral direction until it enters a xylem vessel. Surrounding the xylem vessels is an endodermis, which are impermeable cells that form the Casparian strip. The Casparian strip allows some control over the flow of water into the xylem vessels. Phloem is composed of sieve tube cells and companion cells. The sieve tube cells are larger cells that contain no nucleus. The companion cells are smaller with a nucleus that are adjacent to the sieve tube cells.