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Plant Defense Mechanisms from Pathogens

By: HWC, Views: 6083

Plants and pathogens have coevolved such that pathogens can recognize plants by the sugars, or other molecules, they produce. Plants, in turn, can recognize pathogens by the molecules they produce. The ability to recognize pathogens allows plants to activate defense systems that can prevent wides...

Role of complement proteins

By: HWC, Views: 6393

• Non-specific and specific defense mechanisms work through the functions of complement proteins. • As soon as pathogens penetrate the physical barrier of the skin, other resistance mechanisms begin. • Cells, such as macrophages, phagocytize pathogens. • These cells increase exposu...

Endocytosis - pinocytosis, receptor mediated and Transcytosis

By: HWC, Views: 6565

Pinocytosis is the process in which a cell "drinks" a tiny droplet Of extracellular fluid, including its solutes. Pinocytosis (Cell Drinking) is the process by which the cell takes in fluids (as well as any small molecules dissolved in those fluids). • The plasma membrane folds inward to...

Cytotoxic T cell receptors, activation, proliferation, differentiation & action

By: HWC, Views: 6983

• Most cells which have CD8 on their surface become cytotoxic T cells (Tc cells). • CD8 T cells recognize a foreign antigen when it is presented in conjunction with the protein, MHC-I. • Nearly all nucleated cells in the body express MHC-I molecules. • T cells that recognize self-pe...

Neural Reflex Arc Animation

By: Administrator, Views: 9814

A reflex arc is a neural pathway that controls a reflex. In vertebrates, most sensory neurons do not pass directly into the brain, but synapse in the spinal cord. This allows for faster reflex actions to occur by activating spinal motor neurons without the delay of routing signals through the bra...

Apicomplexan life cycle Animation

By: HWC, Views: 972

Malaria is caused by the sporozoan, Plasmodium. It is transferred to humans by mosquitoes. When an infected mosquito feeds, infective sporozoites move from her salivary glands into the human body. The bloodstream carries the sporozoites to the liver. Here, they reproduce asexually and...

Exocytosis - secretion

By: HWC, Views: 6628

Exocytosis is another method of vesicular transport that moves large volumes Of fluid or chemicals out of the cell. It is a process by which a cell transports secretory products through the cytoplasm to the plasma membrane. A examples of cellular secretory products: 1. Secreted protein - enzym...

Facilitated Diffusion - Glucose transport

By: HWC, Views: 6886

Transmembrane proteins help solutes that are too polar or too highly charged move through the lipid bilayer The processes involved are: Channel mediated facilitated diffusion Carrier mediated facilitated diffusion In facilitated diffusion, molecules only move with the aid of a protein i...

Natural Selection, Species Isolation and Real World Example

By: HWC, Views: 6069

`Natural selection' is the process in which organisms with adaptive traits survive and breed in greater number than organisms without such traits. Eventually, almost all of the individuals in the population will have the same adaptive trait. This was the concept presented by Charles Darwin in ...