Early scientists developed major principles of development via simple experiments. driesch separated the cells of a two cell se urchin embryo and each produced a whole, but smaller embryo. in contrast, when roux killed one of the two cells of a two cell frog embryo, only half an embryo developed. what does this contrast tell us about cell fates?

Every compound can be represented by a chemical formula. a chemical formula is the set of symbols showing the elements that make up a compound and their proportions. water’s chemical formula is h 2 2 o. that means a molecule of water contains two atoms of hydrogen and one atom of oxygen chemically bonded. a molecule is a group of two or more atoms bonded together. molecules can range in size from two to thousands of atoms. a molecule of a compound is the smallest unit of that compound. every molecule of water has all the physical and chemical properties of water. that’s because every molecule of water is made of the same elements in the same proportions: two hydrogen atoms and one oxygen! which of the following is a true statement? a every molecule of the same compound will have different properties. b every molecule of a compound has the same proportion of elements. c molecules can be physically separated into smaller units of a compound. d molecules cannot be represented by chemical formulae.

Read the sentence. “yesterday we arrived late for the outdoor concert in the city gardens.” which words in the sentence are adverbs? a. late; city b. yesterday; outdoor c. yesterday; late d. outdoor; city

Which mechanism of transport takes place when solute particles move from a region of high concentration to a region of low concentration? active diffusion isotonic osmosis