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Cognitive development by Piaget (Preoperational stage or intelligence)

By: HWC, Views: 6933

The next stage of cognitive development proposed by Piaget, is the preoperational stage, roughly between the ages of 2 and 7. At this stage Piaget asserted that a child has what he called preoperational intelligence. hey can mentally representing objects, but do not have a system for organising...

Pasteur's Experiment

By: HWC, Views: 7105

Louis Pasteur designed a procedure to test whether sterile nutrient broth could spontaneously generate microbial life. To do this, he set up two experiments. In both, Pasteur added nutrient broth to flasks, bent the necks of the flasks into S shapes, and then boiled the broth to kill any existing...

Bacteriophage (Virus) - Mice Experiment

By: HWC, Views: 7446

Also known as phages, these viruses can be found everywhere bacteria exist including, in the soil, deep within the earth's crust, inside plants and animals, and even in the oceans. Bacteriophages (phages) are viruses of bacteria that can kill and lyse the bacteria they infect. ... The lethalit...

Miller's reaction chamber experiment Animation

By: HWC, Views: 1302

A simple diagram of Stanley Miller and Harold Urey's experimental apparatus. The lower portion of the apparatus was filled with water. The upper portion was filled with a mixture of gases that simulated the earth's early atmosphere. Examples are methane, ammonia, hydrogen and carbon dioxide. ...

Kinetic parameters & Kinetic experiment

By: HWC, Views: 7576

Kinetics is a measure of the speed or rate of a chemical reaction. A study of kinetics allows us to determine which variables to control (temperature, reactants, catalysts) and how to vary them in order to maximize the amount of products formed and minimize the time involved. Vmax = maximum ve...

Photosynthesis and Van Helmont Experiment

By: HWC, Views: 6981

All energy on Earth comes from a star, the Sun. Light must travel 160 million kilometers to reach Earth where plants capture this light energy and convert it to chemical energy in the form of sugars. This biochemical process is called PHOTOSYNTHESIS. The summary equation for photosynthesis is ...

How does an animal choose what food to eat?

By: HWC, Views: 7182

One might assume that natural selection has influenced the foraging behaviors of animals, and that most animals forage efficiently, spending the least energy to gain the most nutrients. This is the underlying assumption of optimality modeling, a scientific approach to studying foraging behavior. ...

The Hypothalamus: The Body's Thermostat (Human Thermostat)

By: HWC, Views: 6958

Normal body function requires a relatively constant body temperature, which is regulated by the body's thermostat, a region of the brain called the hypothalamus. The hypothalamus generates a temperature set point for the body and appears to be the major site for the integration of temperature inf...

Pressure Flow Model Animation

By: HWC, Views: 6993

This apparatus of beakers A and funnels simulates the flow of a sucrose solution in the phloem of a plant. The funnels and connecting tube represent a sieve tube of the phloem. Differentially permeable membranes cap the funnels at the source and sink ends, allowing water, but not sucrose, to cros...