âI think weâve read every single book they have.â Mark chuckled. He still wasnât ready to put the children downâWill was hanging off of one hip, his hand on Markâs shoulder as he stoically looked down at Bridget, and Mabel had nuzzled into the crook of Markâs neck with a contented sigh.
Diatoms are producers within the food chain. A unique feature of diatom cells is that they are enclosed within a cell wall made of silica (hydrated silicon dioxide) called a frustule. These frustules show a wide diversity in form, but are usually almost bilaterally symmetrical, hence the group name.
Diatoms are delicate unicellular organisms that have a yellow-brown chloroplast that enables them to photosynthesize. Their cell walls are made of silica almost like a glass house. The construction of the cell wall, called the frustule, consists of two valves that fit into each other like a little pill box.The colour of the chloroplast is yellow-brown instead of the green we know of other creatures that use light as a source for energy.There are two different groups of diatoms, the pennates which are pen-shaped and the centric which are like a cylinder. In fresh water most diatoms you will see are of the pennate type.he colour of the chloroplast is yellow-brown instead of the green we know of other creatures that use light as a source for energy. There are two different groups of diatoms, the pennates which are pen-shaped and the centric which are like a cylinder. In fresh water most diatoms you will see are of the pennate type.