In this learning object the student will learn that regardless of the surface onto which a blood droplet is falling, the angle or velocity at which it does so, or the volume of the droplet, there are four distinct phases involved in the reaction of a moving droplet with impact against a surface.
Learners observe how a blood drop in flight continually accelerates and increases in velocity over time. As the drop falls, resistance accumulates. The increase in stain diameter relative to distance of a typical 50 ml drop of blood is represented here. This activity has audio content.
This learning object shows how blood droplets are held together by a strong cohesive molecular force that produces surface tension in each drop and on the external force. Surface tension pulls the surface molecules of a liquid toward its interior, decreasing the surface area and causing the liquid to resist penetration.
In this learning object the student will learn how to measure a stain and calculate angles of impact. Determining the angle of impact for bloodstains takes advantage of the trigonometric functions (Sine function).
A mathematical relationship exists between the width and length of an elliptical bloodstain which allows for the calculation of the angle of the impact for the original spherical drop of blood.
Given well formed stains we can accurately measure the width and length by simply dividing the stain along it’s major and minor axis. The opposite halves would be generally equal to each other which aids in establishing the impact angle.
In this interactive object, learners read the definitions of the parts of a cell and assemble a basic eukaryotic cell in a drag and drop exercise. A matching quiz involving cell terms and their definitions completes the activity.
Building Core Abilities During Student Learning Through Formative and Summative Assessment
This learning object gives instructors an opportunity to review the definitions of formative and summative assessment and list examples of the evaluations they use. In a drag and drop exercise, they classify a variety of assessment tools as either formative or summative.
In this interactive object, learners read the definitions of prefixes and suffixes that relate to the digestive system. In a drag and drop exercise, the learners combine word components to form medical terms.