A HOX gene called Pax6 is required for developing light sensing eyes (or eye-like structures) in a range of taxa including Cnidaria, Mollusca, Arthropoda, and Chordata. Humans (Chordata) and squid (Mollusca) have complex eyes with many shared features, like a lens, that are NOT found in other taxa that have eyes or eye-like structures. Which of the following statements is TRUE?A. If human eyes and squid eyes are analogous, then the Pax6 gene in humans and squid will be nearly identical. B. If human eyes and squid eyes are analogous, then their shared common ancestor would also have complex eyes. C. If human eyes and squid eyes are homologous, then the Pax6 gene in humans and squid will be nearly identical. D. If human eyes and squid eyes are homologous, then they have independent evolutionary origins.

Match the descriptions / definitions with the term they best describe 1. three dimensional relationship of the different polypeptide chains in a multisubunit protein or protein complex 2. common folding pattern in proteins in which a linear sequence of amino acids folds into a right-handed coil stabilized by internal hydrogen-bonding between polypeptide backbone atoms. 3. the amino acid sequence of a protein 4. a region on the surface of a protein that can interact with another molecule through noncovalent bonding. 5. three-dimensional arrangement of alpha-helices and beta-sheets within a single polypeptide, typically stabilized by a variety of noncovalent bonds, including ionic and hydrogen bonds, and nonpolar interactions / hydrophobic force. 6. the chain of repeating carbon and nitrogen atoms, linked by peptide bonds, in a protein. 7. common structural motif in proteins in which different sections of the polypeptide chain run alongside each other and are joined together by hydrogen bonding between atoms of the polypeptide backbone. 8. portion of a polypeptide chain that has a discrete tertiary structure of its own and can often fold independently of the rest of the chain 9. regular local folding patterns in a protein, including alpha-helix and beta-sheet a. primary structure b. beta-sheet c. protein d. coiled-coil e. polypeptide backbone f. secondary structure g. side chain h. tertiary structure i. binding site j. alpha-helix k. quaternary structure l. protein domain

Which gas found in the earth's atmosphere greatly impacts the daily range of temperature on earth. a) oxygen b) hydrogen c) nitrogen d) water vapor

Drag each description to the correct location on the image. not all descriptions will be used. describe the parts of a comet. the frozen part of the comet the atmosphere of gases and dust formed when the nucleus vaporizes tail made of small, solid dust particles tail made of ions that appears to point away from the comet's orbit