8  p o i n t s! which of the following is a characteristic of a scientific experiment? its results always support the hypothesis. it shows cause and effect relationships. it is performed in nature. it can be performed only once.

Some birds look for food near cattle and other livestock. the movement of the cattle churns up the ground, making insects available to the birds. the cattle appear to be unaffected by the presence of the birds. what kind of relationship exists between the birds and the cattle? o a. parasitism o b. commensalism o c. predation o d. mutualism

Which of the following happened during the precambrian era? the first prokaryotic cells the first eukaryotic cells development of photosynthesis all of the above

We all have different forms of genes from our parent(s).what are these different forms called? a. alleles b. characters c. dna d. resources