Answer the following question given this paragraph: Analogous structures are structures that are similar in unrelated organisms. The structures are similar because they evolved to do the same job, not because they were inherited from a common ancestor. For example, the wings of bats and birds, shown in Figure below , look similar on the outside. They also have the same function. However, wings evolved independently in the two groups of animals. This is apparent when you compare the pattern of bones inside the wings. Q: What term is used to describe structures that are similar in unrelated organisms? Choices: - reproductive - symbolic - isolated - analogous A:
analogous
Answer the following question given this paragraph: The Precambrian Supereon (4.6 billion544 million years ago) is the first major division of the geologic time scale. The first living cells may have evolved around 4 billion years ago. By 1 million years ago, the first multicellular eukaryotes had evolved. The Precambrian ended with the first of six mass extinctions that occurred during Earth's history. Q: The first living cells may have evolved around how long ago? Choices: - 900,000 years - 6 billion years - 2.2 billion years - 4 billion years A:
4 billion years
Q: Answer the following question given this paragraph: A whole molecule may also have a separation of charge, depending on its molecular structure and the polarity of each of its bonds. If such a charge separation exists, the molecule is said to be a polar molecule (or dipole); otherwise the molecule is said to be nonpolar. The dipole moment measures the extent of net charge separation in the molecule as a whole. We determine the dipole moment by adding the bond moments in three-dimensional space, taking into account the molecular structure. For diatomic molecules, there is only one bond, so its bond dipole moment determines the molecular polarity. Homonuclear diatomic molecules such as Br2 and N2 have no difference in electronegativity, so their dipole moment is zero. For heteronuclear molecules such as CO, there is a small dipole moment. For HF, there is a larger dipole moment because there is a larger difference in electronegativity. When a molecule contains more than one bond, the geometry must be taken into account. If the bonds in a molecule are arranged such that their bond moments cancel (vector sum equals zero), then the molecule is nonpolar. This is the situation in CO2 (Figure 7.27). Each of the bonds is polar, but the molecule as a whole is nonpolar. From the Lewis structure, and using VSEPR theory, we determine that the CO2 molecule is linear with polar C=O bonds on opposite sides of the carbon atom. The bond moments cancel because they are pointed in opposite directions. In the case of the water molecule (Figure 7.27), the Lewis structure again shows that there are two bonds to a central atom, and the electronegativity difference again shows that each of these bonds has a nonzero bond moment. In this case, however,. Q: Why do homonuclear diatomic molecules have zero dipole moment? Choices: - no electrical attraction - no activation energy - at homeostasis - no difference in electronegativity A:
A: no difference in electronegativity
Question: Answer the following question given this paragraph: Bacteria lack many of the structures that eukaryotic cells contain. For example, they don't have a nucleus. They also lack membrane-bound organelles, such as mitochondria or chloroplasts. The DNA of a bacterial cell is also different from a eukaryotic cell. Bacterial DNA is contained in one circular chromosome, located in the cytoplasm. Eukaryotes have several linear chromosomes. Bacteria also have two additional unique features: a cell wall and flagella. Some bacteria also have a capsule outside the cell wall. Q: How many chromosomes do bacterial dna have? Choices: - one rectangular chromosome - one triangular chromosome - one simple chromosome - one circular chromosome A:
Answer: one circular chromosome
*Question*
Answer the following question given this paragraph: The autonomic nervous system carries nerve impulses to internal organs. It controls activities that are not under your control, such as sweating and digesting food. The autonomic nervous system has two parts:. Q: What system carries nerve impulses to internal organs, controlling activities that are not under your control, such as sweating and digesting food? Choices: - limbic nervous system - circulatory nervous system - hormonal nervous system - autonomic nervous system A:
**Answer**
autonomic nervous system
(Question)
Answer the following question given this paragraph: The most important difference between synthetic and naturally occurring polymers is that the former usually contain very few different monomers, whereas biological polymers can have as many as 20 different kinds of amino acid residues arranged in many different orders. Chains with less than about 50 amino acid residues are calledpeptides, whereas those with more than about 50 amino acid residues are calledproteins. Many proteins are enzymes, which are catalysts that increase the rate of a biological reaction. Q: What role do proteins play in a biological reaction? Choices: - amino acid chains - antioxidants - reverse hormones - act as catalysts A:
(Answer)
act as catalysts