Which of the following is true about scientific theories? i. new research is often done to learn more about existing scientific theories. ii. scientific theories can be revised, changed, or even rejected. iii. scientific theories are considered to be facts and cannot ever be modified. iv. new scientific theories can be formed to explain new phenomena.

The phylogenetic tree illustrates the relationship between humans and our closest living relatives. the tree was based on biochemical comparisons, including dna and amino acid sequences. according to the biomolecular data, we could infer that

In 1992, hurricane andrew left a wake of destruction through florida. one victim of the storm was a reptile-breeding facility. over 900 burmese pythons were set free, and today thousands of pythons live in florida. these pythons are an invasive species, or a harmful species not native to the region. 1. what impacts do you think the burmese pythons might have on local ecosystems

The fruit of a certain plant is sweet and fleshy. the seeds of this plant have a seed coat that is fairly tough. the seeds germinate better if they are exposed to acid, or scarification. what is the most likely type of dispersal for this seed? water animal wind