8th Grade Life Science

Diversity Of Life

1. In classifying organisms, biologists consider details of internal and external structures to be more important than behavior or general appearance. Similarities among organisms can be used to infer the degree of relatedness among organisms. (AKSci - A.12)

o Create a dichotomous key classifying up to 10 objects and/or organisms.

2. Like other animals, human beings have body systems for obtaining and providing energy, defense, reproduction, and the coordination of body functions. (AKSci - A.10)

o Describe and illustrate how the functions of multicellular organisms relate to the life processes occurring at the system level.

o Describe effects if a system breaks down.

Genetics

1. In sexual reproduction, a single specialized cell from a female merges with a specialized cell from a male. As the fertilized egg, carrying genetic information from each parent, multiplies to form the complete organism the same genetic information is copied in each cell. (AKSci - A.11)

o Complete punnett square and describe phenotypes from genotypes.

2. New varieties of cultivated plants and domestic animals have resulted from selective breeding for particular traits. (AKSci - A.13)

o Cite hybrid examples of plants and/or animals and construct a genetic phenotype tree.

Ecology

1. Two types of organisms may interact with one another in several ways: They may be in a producer/consumer, predator/prey, or parasite/host relationship. Or one organism may scavenge or decompose another. Relationships may be competitive or mutually beneficial. Some species have become so adapted to each other that neither could survive without the other. (AKSci - A.9, A.13, A.14a)

o Create a model of an ecosystem incorporating food webs.

2. In all environments -- freshwater, marine, forest, desert, grassland, mountain, and others -- organisms with similar needs may compete with one another for resources, including food, space, water, air, and shelter (together referred to as "habitat"). In any particular environment, the growth and survival of organisms commonly depend on the quality and quantity of the habitat. Other determining factors include predation, parasitism, etc. (AKSci - A.9, A.14a, A.14c)

o Construct and interpret graphs (bar, line, pie histogram) from data illustrating the correlation between a population in an ecosystem and a biotic or abiotic factor.

Natural Selection

1. Many thousands of layers of sedimentary rock provide evidence for the long history of the earth and for the long history of changing life forms whose remains are found in the rocks. More recently deposited rock layers are more likely to contain fossils resembling existing species. (AKSci - A.13)

o Draw/create a model of a cross section of sedimentary rock layers and place 5 fossils appropriately on the model.

2. Under normal conditions, organisms produce many more young than the environment can support, causing intense competition for available resources. (AKSci - A.9)

3. Individual organisms with certain traits are more likely than others to survive and have offspring. Changes in environmental conditions can affect the survival of individual organisms and entire species. (AKSci - A.13)

4. Small differences between parents and offspring can accumulate (through selective breeding) in successive generations so that descendants are very different from their ancestors. (AKSci - A.13)

o Diagram or explain how genetic material is disseminated during the formation of sex cells and passed to the next generation.

5. Similarities among organisms are found in internal anatomical features, which can be used to infer the degree of relatedness among organisms. (AKSci - A.13)

o Describe or identify similarities between different species.

Human Biology

1 Following fertilization, cell division produces a small cluster of cells that then differentiate by appearance and function to form the basic tissues of an embryo. During the first three months of pregnancy, organs begin to form. During the second three months, all organs and body features develop. During the last three months, the organs and features mature enough to function well after birth. Patterns of human development are similar to those of other vertebrates. (AKSci - A.10)

o Observe, describe, and measure changes that occur in an organism (e.g., bean plant, butterfly, frog, chicken) as it develops from a seed or fertilized egg into an adult and compare to a human.