5. Fig. 3.2 (Top left) Linked molecules (organic bases) make up the “rungs” on DNA’s twisted “molecular ladder.” The order of these molecules serves as a code for genetic information. The code provides a genetic blueprint that is unique for each individual (except identical twins). The drawing shows only a small section of a DNA strand. An entire strand of DNA is composed of billions of smaller molecules. (Bottom left) The nucleus of each cell in the body contains chromosomes made up of tightly wound coils of DNA. (Don’t be misled by the drawing: Chromosomes are microscopic in size and the chemical molecules that make up DNA are even smaller.)
6. Fig. 3.3 Gene patterns for children of brown-eyed parents, where each parent has one brown-eye gene and one blue-eye gene. Since the brown-eye gene is dominant, 1 child in 4 will be blue-eyed. Thus, there is a significant chance that two brown-eyed parents will have a blue-eyed child.
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15. Fig. 3.5 Infant imitation. In the top row of photos, Andrew Meltzoff makes facial gestures at an infant. The bottom row records the infant’s responses. Videotapes of Meltzoff and of tested infants helped ensure objectivity. (Photos courtesy of Andrew N. Meltzoff.)
16. Fig. 3.7 Motor development. Most infants follow an orderly pattern of motor development. Although the order in which children progress is similar, there are large individual differences in the ages at which each ability appears. The ages listed are averages for American children. It is not unusual for many of the skills to appear 1 or 2 months earlier than average or several months later (Frankenberg & Dodds, 1967; Harris & Liebert, 1991). Parents should not be alarmed if a child’s behavior differs some from the average.
20. Fig. 3.9 The traditional view of infancy holds that emotions are rapidly differentiated from an initial capacity for excitement. (After K.M.B. Bridges, 1932. From “Emotional Development in Early Infancy.” Reprinted by permission of the Society for Research in Child Development.)
21. Fig. 3.10 Infants display many of the same emotional expressions as adults do. Carroll Izard believes such expressions show that distinct emotions appear within the first months of life. Other theorists argue that specific emotions come into focus more gradually, as an infant’s nervous system matures. Either way, parents can expect to see a full range of basic emotions by the end of a baby’s first year. Over the first 2 years, children become increasingly active in initiating emotional exchanges with parents (Grolnick, Cosgrove, & Bridges, 1996).
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24. Fig. 3.17 Children under age 7 intuitively assume that a volume of liquid increases when it is poured from a short, wide container into a taller, thinner one. This boy thinks the tall container holds more than the short one. Actually each holds the same amount of liquid. Children make such judgments based on the height of the liquid, not its volume.