Life Science Study Guide Answer Key PDF

Life Science Study Guide Answer Key Heredity and DNA 1. Allele-Different/alternate forms (dominant and recessive) of genes are known as alleles- 2. Phenotype-appearance or other detectable characteristics (color). 3. Genotype-the e...

Life Science Study Guide Answer Key Heredity and DNA 1. Allele-Different/alternate forms (dominant and recessive) of genes are known as alleles- 2. Phenotype-appearance or other detectable characteristics (color). 3. Genotype-the entire genetic makeup of an organism, also the combination of genes for one or more specific traits. Uses letter combinations. 4. Heterozygous- (1 of each allele) example. Pp 5. Homozygous-(2 dominant or 2 recessive alleles) example. PP or pp. CODON Wheel Practice Answer Key Natural Selection, Adaptation & Evolution A. Adaptation: A characteristic that helps an organism survive and reproduce in its environment. Adaptations may be physical behaviors B. Species: A group of organisms that can mate with one another to produce fertile offspring. Groups of individuals of the same species living in the same place make up a population. C. Fossil Record: organizes fossils by their estimated ages and physical similarities D. Selective Breeding: The human practice of breeding animals or plants that have certain desired characteristics E. Natural Selection: The process by which individuals that are better adapted to their environment survive and reproduce more successfully than less well adapted individuals do. Helps explain evolution. F. Generation Time: the period between the birth of one generation and the birth of the next generation. 1. Why is structure a better indicator than function to show common ancestry? Structure shows a common ancestor better than function. EX: Bats and whales share a common ancestor (by looking at the bones). We also know that, as flying animals, both bats and insects have wings. If we were to use function to determine common ancestry, we might think –incorrectly- that insects and bats are more closely related than bats and whales are. 2. Describe the four parts of Darwin’s Natural Selection. Overproduction: Ex: Laying thousands of eggs. Some will survive and reach adulthood and some will not. Inherited Variation: Every individual has its own traits. Each tarantula is similar to but not identical to its parents Struggle to Survive: Some may die of disease, some may get caught by predators, only a few make it to adulthood Successful Reproduction: The organisms that are best adapted to their environment are likely to have many offspring that survive  3. Know what vestigial structures are and be able to name a few. Things we no longer require that were useful to us at some point during our evolution. Appendix, molars, goose bumps, tailbone, nictitating membrane, tonsils Human Evolution Define the following terms: A. Extinct-The death of every member of the species. B. Plate Tectonics-Continents/huge pieces of land moved slowly on plates C. Primates-group of mammals that include humans, apes, monkeys, and lemurs (opposable thumbs and binocular vision) D. Hominids- Any human-like species, including us. Bipedal (walks on two legs). Intelligent (large brain, uses tools). E. Homo sapien - Modern human species F. Species- A group of organisms that can mate with one another to produce fertile offspring. 1. DESCRIBE the 5 major evolutionary developments from early hominids to modern humans. Changes in brain size & skull shape-Smaller to larger brain capacity Spinal insertion moves from rear to base of skull Hand Shape- Development of more flexible opposable thumb allowed advanced tool use Pelvis Shape- Allowed early hominids to stand & walk upright Gave advantage of being able to see around them on the savannah Spine Shape- Changed from “C” to “S” shaped Jaw Size-Jaw has reduced in size, reflecting changes in species diet Size of teeth have generally decreased, especially canines Classification Smiley Dichotomous Key Answer Key