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Welcome to my TEAS Exam Prep blog. I hope it will help you prepare very well for the pre-nursing entrance exam, popularly known as the TEAS exam. This is one of the entrance exams required by some schools for those who want to pursue careers in the nursing field in the USA. I will attempt to break down the review materials into manageable parts so that you can systematically and efficiently prepare for the test with less stress. I will guide you to prepare for the entire content of the test. Hopefully, you will be able to pass after going through these series.


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Wednesday, December 17, 2014

TROPISMS

What is tropism?

It is the turning of all or part of an organism in a particular direction in response to an external stimulus. The response is due to the differential growth of a part of the organism. Note that the whole organism is not displaced or moved from one spot to another. It is a positive or negative response to the external stimulus. A positive response means "towards the stimulus" and a negative response means "away from the stimulus". Tropisms are typically associated with plants but not necessarily restricted to them. Tropism occurs due to the effect of the plant growth hormone called auxin. Tropisms are usually named for the stimulus involved. Here are some examples:
    • Chemotropism: It is the movement or growth in response to chemicals.
    • Geotropism (or gravitropism): It is the movement or growth in response to gravity. For example, the roots grow towards the ground.
    • Heliotropism: It is the movement or growth in response to sunlight. For example, the shoot grows towards the sunlight.
    • Sonotropism: It is the movement or growth in response to sound.
    • Hydrotropism: It is the movement or growth in response to water.
    • Phototropism: It is the movement or growth in response to light or colors of light.
    • Thermotropism: It is the movement or growth in response to temperature.
    • Electrotropism: It is the movement or growth in response to an electric field.
    • Thigmotropism: It is the movement or growth in response to touch or contact. For example, the climbing plants, such as vines, develop tendrils that coil around supporting objects. Touched cells produce auxin and transport it to untouched cells. Some untouched cells will then elongate faster so cell growth bends around the object. 
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