Life Science

Course Description

Life Science is a course that introduces students to living things and their relationship to the environment. The students explore the following:

• Cells
• Ecological Interactions
• Energy Production and Use
• Reproduction and Inheritance
• Classification and Environmental Diversity
• Biological Evolution

The Life Science standards provide a basic foundation for the biological sciences. This curriculum is aligned with the Gateway Biology I course and the K-8 curriculum. Hands-on laboratory investigations, technology, research, inquiry, individual and group activities are used to meet the life science standards. Although the microscope is not addressed directly in the curriculum, it is recommended that students use this investigative tool extensively.

Standard Number: 1.0 Cells

Standard: The student will investigate the structures and functions of the cell membrane, cellular organelles, and component biomolecules related to the major cell processes.

Learning Expectations:

The student will

• 1.1 compare and contrast the chemistry of biomolecules and investigate their roles in cell structure and metabolism.
• 1.2 explore and compare the organelles of different cell types.
• 1.3 probe the composition of the cell membrane and it significance to homeostasis.
• 1.4 analyze the various cell processes.

Performance Indicators:

At Level 1, the student is able to

• identify major cellular organelles, given a diagram.
• distinguish between plant and animal cells, given diagrams or scenarios.
• predict the movement of water molecules across the cell membrane, given solutions of different concentrations.

At level 2, the student is able to

• compare and contrast the cell cycle in plant and animal cells, given a diagram.
• relate the structure of the cell membrane to the role of maintaining homeostasis.
• define selective permeability, homeostasis, and plasmolysis.
• distinguish between proteins, carbohydrates, and lipids.

At Level 3, the student is able to

• distinguish between active and passive transport, given different molecules and concentrations.
• distinguish among various types of nucleic acids.

Sample Task:

Cell Processes: Place one group of raisins in a glass of distilled water. Place a second group of raisins in a glass of vegetable oil. Allow to stand overnight. Record any changes in size and/or shape. On the second day, place all the raisins in salt water. Allow the raisins to stand overnight. Observe any changes in size and/or shape. Determine in which solution the cell membrane is permeable.

Hint: During osmosis, water moves from a greater concentration through a membrane to an area of lesser water concentration. The raisins were dryer inside, thus the water in the glass moved through the cell membranes into the raisins. As the cells filled with water, the raisins became plump and fluffy.

Integration/Linkages:

nutrition, health, physical science, history, art, mathematics, technology, heredity, microscope, chemistry, homeostasis, mitosis, meiosis, research, history, careers

Standard Number: 2.0 Ecological Interactions

Standard: The student will investigate the relationship and interaction between living organisms and their environment.

Learning Expectations:

The student will

• 2.1 distinguish between abiotic and biotic factors in the environment.
• 2.2 compare populations, communities, and ecosystems.
• 2.3 analyze the flow of nutrients and energy in an environment.
• 2.4 distinguish among producers, consumers, and decomposers in food chains, food webs, and ecological pyramids.
• 2.5 distinguish between autotrophs and heterotrophs by comparing plant and animal structures.
• 2.6 contrast different types of symbiotic relationships.
• 2.7 explore how human activities can affect the balance of an ecosystem.

Performance Indicators:

At Level 1, the student is able to

• distinguish between abiotic and biotic factors in an environment.
• distinguish among populations, communities, and ecosystems, given examples.

At Level 2, the student is able to

• examine nutrient and energy relationships in an energy pyramid.
• classify organisms as producers, consumers, and decomposers, given their behavior and environment.
• infer how human activities can affect the balance of an ecosystem.
• differentiate among symbiotic relationships, given descriptions of commensalism, parasitism, and mutualism.

At Level 3, the student is able to

• interpret population growth curves.

Sample Task:

Eat or Be Eaten: Draw a food web that contains the following: bread crumbs, food scraps, pigeon, mouse, cockroach, cat, rat, bacteria, starling, spider, and fly. Where would you be likely to find this food web in nature? What feeding level is missing from this food web? Why is this feeding level missing?

Additional Activities:

• Make an ecological pyramid. Label each level.
• How many different food chains can you make?
• Make a chart of the producers, herbivores, and carnivores.
• Make a chart listing how many food chains each item in the above list is included.
• Based on the food chains and the chart, what is the top carnivore in this food web?

Integration/Linkages:

earth science, language arts, geology, economics, ecology, recycling, careers, geography, art, chemistry, adaptations, energy transfer, evolution, populations, research, biogeochemical cycles, symbiotic relationships, webbing, classification

Standard Number: 3.0 Energy Production and Use

Standard: The student will compare and contrast the processes involved in the transfer of energy during photosynthesis and respiration.

Learning Expectations:

The student will

• 3.1 identify the reactants and products of photosynthesis and respiration.
• 3.2 compare and contrast the processes of photosynthesis and respiration.
• 3.3 analyze the carbon, oxygen, and water cycles.
• 3.4 distinguish between aerobic and anaerobic respiration.

Performance Indicators:

At level 1, the student is able to

• identify the cell organelles in which photosynthesis and respiration occur, given diagrams or descriptions.
• identify the reactants and products of photosynthesis and respiration, given equations.

At Level 2, the student is able to

• interpret carbon, oxygen, and water cycles, given diagrams.
• distinguish between aerobic and anaerobic respiration, given descriptions.

At Level 3, the student is able to

• analyze the relationship between photosynthesis and respiration, given diagrams and descriptions.

Sample Task:

Plants as food producers:

Determine if plant leaves contain and/or produce starch.

What is the positive test for starch?

Each group of students will need paper towels, goggles, a petri dish, jar with a lid, tongs, 250 mL beaker, a very pale green leaf, rubbing alcohol, dropper, and tincture of iodine.

Have each group place their leaf in the jar, then add 250 mL of rubbing alcohol. Seal the jar and let it stand for one day. After one day remove the leaf and place it in the petri dish or any shallow dish. Record your observations of the leaf. Add enough tincture of iodine to cover the leaf. Have the students record and report orally their observations. Ask the students why the leaf was soaked in the alcohol for 24 hours. Have the students infer if this activity proves that a plant leaf produces starch, contains starch or both.

Integration/Linkages:

ecology, physical science, chemistry, mathematics, technology and careers, research, interactions, equations, diversity, concept maps

Standard Number: 4.0 Reproduction and Inheritance

Standard: The student will investigate how patterns of inheritance are linked to reproduction and infer that hereditary information contained in DNA is transmitted from parent to offspring.

Learning Expectations:

The student will

• 4.1 distinguish between sexual and asexual reproduction.
• 4.2 organize the stages of cell division sequentially for mitosis and meiosis.
• 4.3 distinguish between dominant and recessive traits.
• 4.4 distinguish between purebred and hybrid traits.
• 4.5 explore various modes of inheritance (i.e. co-dominance, incomplete dominance, multiple alleles, sex-linked, and polygenic traits) using the principles of Mendelian inheritance.
• 4.6 relate genetic mutations with changes in DNA.
• 4.7 distinguish between mitosis and meiosis.

Performance Indicators:

At Level 1, the student is able to

• distinguish between asexual and sexual reproduction, given examples.
• distinguish between mitosis and meiosis.
• recognize the inheritance of traits using a Punnett Square.
• identify the dominant trait resulting from a monohybrid cross, using the genotypes of the parents.
• determine the phenotype given a particular gene combination.

At Level 2, the student is able to

• determine the genotypic and phenotypic ratio of a monohybrid cross.
• determine the dominant and recessive trait given the phenotypic ratios from a monohybrid cross.
• determine the number of chromosomes following mitosis and meiosis, given the number of chromosomes in the original cell.

At Level 3, the student is able to

• recognize and distinguish among sex-linked, co-dominant, incomplete dominant, polygenic, and multiple allele traits.
• determine the nature of the mutation that may have occurred when comparing complementary DNA strands.

Sample Task:

Expected and Observed Results: Each group or pair of students will need 100 red beans, 100 white beans and two paper bags. Place 50 red and 50 white beans in each bag. Label one bag, female, and label the other bag, male. Make a chart with four columns. Column one is the pick number, two is the red/red combination, three is the red/white combination, and four is the white/white combination. Before picking, let students predict how many combinations will be red/red (RR), how many will be red/white (Rr), and how many will be white/white (rr). There will be 50 picks. Without looking into the bag, one bean is withdrawn from each bag. Record the combination as red/red, red/white, or white/white. Return the beans to the original bag after each pick. Total the number in each of the last three columns. Compare what happened to what was expected. Have students discuss reasons for a difference.

Going Further: If more than one class is doing this activity or if one class repeats the activity, combine the results for several classes. Total the results and compare what happened in the larger sample size to the predicted results. Discuss why sample size is important in predicting outcomes.

Integration/Linkages:

careers, mathematics, technology, statistics, wellness, current events, debates, bio-ethical dilemma, communication, research, social studies, geography, biological evolution, probability, mitosis and meiosis

Standard Number: 5.0 Classification and Environmental Diversity

Standard: The student will investigate the diversity of organisms by analyzing taxonomic systems, exploring diverse environments, and comparing life cycles.

Learning Expectations:

The student will

• 5.1 establish criteria for designing a classification system.
• 5.2 compare systems of classification.
• 5.3 infer the types of organisms native to specific major biomes.
• 5.4 distinguish among the life cycles of plants and animals.

Performance Indicators:

At Level 1, the student is able to

• infer the need for a biological classification system.
• compare Aristotle’s classification system to the Linnean system of classification.
• explain how binomial nomenclature is used to name living things.
• identify, in correct sequence, the seven major classification groups.
• identify the characteristics of each kingdom in the 6-kingdom classification system
• infer the relatedness of different organisms using the Linnean system of classification, given pictures of a variety of different plants or animals and a classification key.
• distinguish between the six major land biomes and the two major water biomes, given descriptions.

At Level 2, the student is able to

• classify organisms, given a dichotomous key containing characteristics of the organisms.
• infer animals or plants indigenous to an environment, given pictures or diagrams of organisms and a description of the environment.
• determine whether an organism undergoes complete or incomplete metamorphosis, given pictures or diagrams or the organism in its stages of development.
• infer the body symmetry of an organism, given a diagram or picture of the organism.

Sample Task:

To observe protective coloration. List at least three organisms that use protective coloration. Students will need 13mm pieces of different color pipe cleaners, a meter stick, 4 wooden stakes, and string. Have the students use the meter stick, stakes and string to mark off a 5m plot of grassy land. Have one partner spread the pipe cleaner pieces evenly in the marked plot of grass. Instruct a group member to pick up as many pieces of the pipe cleaner that they can find in 5 minutes. The group should construct a chart to record the number and each color of pipe cleaner found. What colors were found most often? Why? What color(s) were found least often? Why? Why is blending with the environment important to the survival of some species of animals? Can you think of other organisms that use protective coloration?

Integration/Linkages:

diversity, mathematics, geography, research, writing, careers, technology, anatomy and physiology, history, biological evolution, classification

Standard Number: 6.0 Biological Evolution

Standard: The student will investigate physical, environmental, and chemical evidence that indicates that life on earth has changed over time.

Learning Expectations:

The student will

• 6.1 investigate the process of fossil formation.
• 6.2 interpret various forms of evidence for biological evolution.
• 6.3 distinguish between the concepts of relative and absolute dating.
• 6.4 relate environmental change to natural selection, mutation, and adaptation that may lead to the emergence of a new species or the extinction of an existing species.
• 6.5 use current knowledge of DNA and comparative anatomy as evidence for biological change.

Performance Indicators:

At level 1, the student is able to

• arrange various fossils on a diagram of sedimentary rock strata, using a collection of fossil pictures.
• determine the process of fossil formation, given a set of fossil pictures or fossil samples.
• compare and contrast relative and absolute dating techniques.

At level 2, the student is able to

• predict how environmental change can contribute to the emergence of a new species, change in a population size, or extinction of an existing species.
• infer how natural selection explains why species with a common ancestor have adapted differently.
• use a geologic time scale to associate the impact of global environmental changes with the dominant species of each geologic period.

At level 3, the student is able to

• compare homologous and analogous structures to determine the relatedness of species, using pictures.
• explain the relatedness of species using DNA strands.

Sample Task:

Natural Selection: the process in which organisms with favorable variations of traits survive in their environment and reproduce offspring that now contain these variations or changes. Give each group of students a baggie or container with 50 squares of newsprint and fifty squares of equal-sized colored construction paper. The group members will act as predators, by taking turns selecting squares of paper. Have the group leader toss the paper squares on an open piece of newspaper. Each member of the group should take turns picking up squares of paper that he/she sees first. Tell each person to repeat this procedure 5 times.

Record the number and type of paper squares collected by each group member. Total the number of squares not selected by the group members. Each group should graph their data and compare the results with the entire class. Ask the groups what the uncut newspaper represented? What do the paper squares represent? How does this activity demonstrate natural selection? Could this activity explain the necessity for color change in peppered moths?

Note both the colored paper and newsprint can be cut into shapes instead of squares.

Integration/Linkages:

geography, earth science, geology, careers, paleontology, technology, mathematics, physical science, chemistry, research, genetics, art, graphing, genetics, populations, disease, diversity