Search results for: 'Griffith's experiments'

Watch Later 1:12

By: HWC, Views: 4880

In the late 1920s, Fred Griffith was attempting to develop a vaccine against a bacterium that causes pneumonia. To find out why two strains of the bacteria differed in their deadliness, he injected mice with four different mixtures. Mice injected with R cells remained healthy. When Griffith ex...

Watch Later 1:47

Mendel's Principles of Inheritance (Father of Genetics)

By: HWC, Views: 7352

Gregory Johann Mendel, a monk living in the mid-1800's, is known as the "Father of Genetics" for his experiments with pea plants in the abbey garden. These experiments led him to deduce the fundamental law of genetics. Mendel was an Augustinian friar who entered, in 1843, the Abbey of St. Thom...

Watch Later 1:05

Hershey Chase Experiments

By: HWC, Views: 4904

Hershey and Chase knew that T4 bacteriophages consist of proteins and DNA. They asked which viral component must enter a bacterial cell to infect it: DNA or protein? They grew viruses with either radioactive sulfur, which labels the viral protein, or radioactive phosphorus, which labels DNA. ...

Watch Later 3:14

Mendel's Pea Experiment

By: HWC, Views: 7169

Sugar snap peas were common garden plants during Mendel's lifetime and many varieties undoubtedly grew in the abbey gardens. An avid gardener. this is where Mendel first made observations about pea plants. He noticed that certain characteristics of peas were passed from generation to generation. ...

Watch Later 2:42

Virtual Enzyme Kinetics & Lineweaver Burk Plot

By: HWC, Views: 7319

• The double-reciprocal (also known as the Lineweaver-Burk) plot is created by plotting the inverse initial velocity (1/V0) as a function of the inverse of the substrate concentration (1/[S]). • This plot is a useful way to determined different inhibitors such as competitive, uncompetitive...

Watch Later 0:47

Mendel's pea plant, Pisum sativum experimental

By: HWC, Views: 5608

Mendel chose the garden pea plant, Pisum sativum, for experimental tests of his ideas about inheritance. Under normal circumstances, the garden pea plant is self-fertilizing. This cross-section shows the gamete-forming structures. Sperm-producing pollen grains form in the stamens. Eggs deve...

Watch Later 1:29

Pasteur's Experiment

By: HWC, Views: 7120

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...

Watch Later 1:51

Cognitive development by Piaget (Preoperational stage or intelligence)

By: HWC, Views: 6949

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...

Watch Later 1:43

Mechanisms for chromosome movement Animation

By: HWC, Views: 4741

At mitotic metaphase, the fully-formed spindle is composed of many microtubules that extend from the poles. Some of these, the kinetochore microtubules, are attached to the kinetochores of each chromosome. Kinetochores are located at the centromeres. At anaphase, sister chromatids separate and...

Search Results