Theodor engelmann broadcast light that had been passed through a prism onto a mat of algae. this exposed different parts of algae to different wavelengths of light. when he added aerobic bacteria to the system, he noted that the largest groups of bacteria aggregated in the areas of the algae illuminated by the blue and red light. what did engelmann discover from this experiment

lizards have adapted to life in the desert. some desert lizards have toes with spiny scales to them run across the sand without sinking. some use the sand to hide from predators, or to search for small animals that they prey upon.

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.