Honors Bio Class 13

Today in class we categorized shells based on their different characteristics such as shape, size, texture, and color. We reviewed what may have caused these species of snails to die, and found that predators may have been the main reason. As we studied the shells closely we noticed little holes in the shells that had been drilled by a special type of snail that fed on other snails. 

This special type of snail has adapted it's tongue to have a drill at the tip. This allows it to drill holes into the shells of others and inject poison. This characteristic was was passed down from parent to baby through a mutation in the DNA.

After the lesson, we began the brine shrimp lab, where we would discover what percentage of NaCl in water suited the shrimp best. First we had to calculate how many grams of NaCl we would need to get the percentage of 0%, 0.5%, 1.0%, 1.5%, and 2.0% in 30 mL of water. After this we poured the different solutions into five different petri dishes and labels them. The next step was to collect the brine shrimp eggs. We did this  by brushing the eggs on to a piece of tape stuck on a glass slide. Before we could place the slides into the solutions we had to record the amount of eggs. After this was finished we placed them into the solutions and would check on them in 24 hours. 

These are some of our different slides

This is a close up

This is what some of the brine shrimp look like

And finally the results after two days:).