STEM is important because it pervades every part of our lives. Science is everywhere in the world around us. Technology is continuously expanding into every aspect of our lives.
Engineering is the basic designs of roads and bridges, but also tackles the challenges of changing global weather and environmentally-friendly changes to our home. Mathematics is in every occupation, every activity we do in our lives. A curriculum that is STEM-based has real-life situations to help the student learn.
Programs like Engineering For Kids integrates multiple classes to provide opportunities to see how concepts relate to life in order to hopefully spark a passion for a future career in a STEM field. STEM activities provide hands-on and minds-on lessons for the student.
STEM professionals designed and built the Hubble telescope to peek into the universe; created the internet ; built the tallest buildings in the world, and continually push our understanding of diseases and new medical treatments. You can count on more job security in a STEM career. Most students graduating with STEM degrees find themselves immediately employed. You learn transferable skills. While it might be difficult to transition from being a geologist to being a software developer, the core focus on both a high level of technical skill and a rigorous approach to problem-solving remains the same in all STEM fields.
A rhizome is a modified stem that grows horizontally underground; it has nodes and internodes. Vertical shoots may arise from the buds on the rhizome of some plants, such as ginger and ferns. Corms are similar to rhizomes, except they are more rounded and fleshy such as in gladiolus.
Corms contain stored food that enables some plants to survive the winter. Stolons are stems that run almost parallel to the ground, or just below the surface, and can give rise to new plants at the nodes. Runners are a type of stolon that runs above the ground and produces new clone plants at nodes at varying intervals: strawberries are an example.
Tubers are modified stems that may store starch, as seen in the potato. A bulb, which functions as an underground storage unit, is a modification of a stem that has the appearance of enlarged fleshy leaves emerging from the stem or surrounding the base of the stem, as seen in the iris.
Stem modifications : Stem modifications enable plants to thrive in a variety of environments. Shown are a ginger Zingiber officinale rhizomes, b a carrion flower Amorphophallus titanum corm c Rhodes grass Chloris gayana stolons, d strawberry Fragaria ananassa runners, e potato Solanum tuberosum tubers, and f red onion Allium bulbs.
Modifications to the aerial stems, vegetative buds, and floral buds of plants perform functions such as climbing, protection, and synthesis of food vegetative propagation. Aerial modifications of stems include the following:. Aerial modifications of stems : Found in southeastern United States, a buckwheat vine Brunnichia ovata is a weedy plant that climbs with the aid of tendrils.
This one is shown climbing up a wooden stake. Privacy Policy. Skip to main content. Plant Form and Physiology. Search for:. Functions of Stems A stem connects the roots to the leaves, provides support, stores food, and holds the leaves, flowers, and buds.
Learning Objectives Summarize the main function and basic structure of stems. Key Takeaways Key Points Most stems are found above ground, but some of them grow underground. Stems can be either unbranched or highly branched; they may be herbaceous or woody. Stems connect the roots to the leaves, helping to transport water, minerals, and sugars to different parts of the plant. Plant stems always have nodes points of attachments for leaves, roots, and flowers and internodes regions between nodes.
The petiole is the stalk that extends from the stem to the base of the leaf. An axillary bud gives rise to a branch or a flower; it is usually found in the axil: the junction of the stem and petiole.
Key Terms node : points of attachment for leaves, aerial roots, and flowers internode : a section of stem between two stem nodes petiole : stalk that extends from the stem to the base of the leaf axillary bud : embryonic shoot that lies at the junction of the stem and petiole that gives rise to a branch or flower.
Learning Objectives Summarize the roles of dermal tissue, vascular tissue, and ground tissue. Key Takeaways Key Points The stem has three simple cell types: the parenchyma, collenchyma, and sclerenchyma cells that are responsible for metabolic functions, repairing and healing wounds, and storing starch. The stem is composed of three tissue systems that include the epidermis, vascular, and ground tissues, all of which are made from the simple cell types..
The xylem and phloem carry water and nutrients up and down the length of the stem and are arranged in distinct strands called vascular bundles. The epidermis is a single layer of cells that makes up the dermal tissue covering the stem and protecting the underlying tissue. Woody plants have an extra layer of protection on top of the epidermis made of cork cells known as bark.
The vascular tissue of the stem consists of the complex tissues xylem and phloem which carry water and nutrients up and down the length of the stem and are arranged in distinct strands called vascular bundles.
Ground tissue helps support the stem and is called pith when it is located towards the middle of the stem and called the cortex when it is between the vascular tissue and the epidermis. Primary and Secondary Growth in Stems Plants undergo primary growth to increase length and secondary growth to increase thickness.
Learning Objectives Distinguish between primary and secondary growth in stems. Primary growth of stems is a result of rapidly-dividing cells in the apical meristems at the shoot tips. Apical dominance reduces the growth along the sides of branches and stems, giving the tree a conical shape. The growth of the lateral meristems, which includes the vascular cambium and the cork cambium in woody plants , increases the thickness of the stem during secondary growth.
Cork cells bark protect the plant against physical damage and water loss; they contain a waxy substance known as suberin that prevents water from penetrating the tissue. The secondary xylem develops dense wood during the fall and thin wood during the spring, which produces a characteristic ring for each year of growth.
Key Terms lenticel : small, oval, rounded spots upon the stem or branch of a plant that allow the exchange of gases with the surrounding atmosphere periderm : the outer layer of plant tissue; the outer bark suberin : a waxy material found in bark that can repel water.
Stem Modifications Stem modifications, either aboveground, underground, or aerial, enable plants to survive in particular habitats and environments. This donor nucleus is then injected into the egg, replacing the nucleus that was removed, in a process called nuclear transfer.
The egg is allowed to divide and soon forms a blastocyst. This process creates a line of stem cells that is genetically identical to the donor's cells — in essence, a clone. Some researchers believe that stem cells derived from therapeutic cloning may offer benefits over those from fertilized eggs because cloned cells are less likely to be rejected once transplanted back into the donor and may allow researchers to see exactly how a disease develops.
Researchers haven't been able to successfully perform therapeutic cloning with humans despite success in a number of other species. However, in recent studies, researchers have created human pluripotent stem cells by modifying the therapeutic cloning process. Researchers continue to study the potential of therapeutic cloning in people. There is a problem with information submitted for this request.
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Stem cells: What they are and what they do Stem cells and derived products offer great promise for new medical treatments. By Mayo Clinic Staff. Open pop-up dialog box Stem cells: The body's master cells Close. Stem cells: The body's master cells Stem cells are the body's master cells. Thank you for Subscribing Our Housecall e-newsletter will keep you up-to-date on the latest health information.
Please try again. Something went wrong on our side, please try again. National Institutes of Health. Accessed July 23, Stem cell basics. Nelson TJ, et al. Stem cell therapy and congenital heart disease.
Journal of Cardiovascular Development and Disease.
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