Search Results

How eudicots (true dicots) differ from monocots Animation

By: HWC, Views: 1509

Most flowering plants are either monocots or eudicots. They have the same tissues, but slightly different features. Monocot seeds have a single cotyledon, or seed leaf. Eudicot seeds have two cotyledons. Monocot flowers usually have petals and other floral parts in multiples of three. Flow...

Muscle Twitch and Muscle Tension - Motor unit size and force

By: HWC, Views: 6904

• A motor unit is a group of muscle cells controlled by a single neuron. • A stimulus of sufficient intensity will cause all the cells in the motor unit to contract. • A single contraction, caused by a single action potential, is called a muscle twitch. • Latent period: A brief per...

Pores and Ion Channels

By: HWC, Views: 5877

Transmembrane channels, also called membrane channels, are pores within a lipid bilayer. The channels can be formed by protein complexes that run across the membrane or by peptides. They may cross the cell membrane, connecting the cytosol, or cytoplasm, to the extracellular matrix. Membrane po...

Body plan of euglena Animation

By: HWC, Views: 978

Euglenoids are single-celled organisms that live in lakes and ponds. A contractile vacuole pumps out the water that diffuses into the cell from its hypotonic surroundings. The body is covered by a translucent pellicle composed of flexible strips of a protein-rich material. Light passe...

Anatomy and Chemical Makeup of a Single Hair (Animation)

By: HWC, Views: 4910

The hair's outer cuticle surrounds hair cells filled with tough keratin macrofibrils. Each macrofibril consists of smaller microfibrils. A microfibril is made up of three keratin polypeptide chains. The chains are linked together by disulfide bonds. A hair consists of keratin chains held...

Reflex arc construction

By: HWC, Views: 6544

• Somatic reflexes are the rapid, predictable, and automatic responses of skeletal muscle to changes in stimuli. • A reflex arc is the pathway followed by the nerve impulse producing the reflex. • Reflex arcs include: • Sensory receptor • Sensory neurons • Integrating c...

Rena arc construction

By: HWC, Views: 6579

• Somatic reflexes are the rapid, predictable, and automatic responses of skeletal muscle to changes in stimuli. • A reflex arc is the pathway followed by the nerve impulse producing the reflex. • Reflex arcs include: • Sensory receptor • Sensory neurons • Integrating cen...

Bond in biological molecules (Ionic, Covalent and Hydrogen bonds)/ How atoms bond?

By: HWC, Views: 3973

Sodium atoms and chloride atoms have unfilled orbitals in their outer shells. The lone electron in the outermost shell of a sodium atom can be pulled or knocked out. This ionizes the atom. It is now a positively charged sodium ion. A chlorine atom has an electron vacancy in its outer shell and...

Type of Cell Junctions - Desmosome, Hemidesmosomes and Gap Junctions

By: HWC, Views: 6994

Cell Junctions: Cell junctions are found in some multi-cellular organisms. They exist of complexes and are found between cells and between cells and other structures. The junctions provide a way for cells to connect and exchange signals. What are tight junctions, desmosomes, and gap junctions...