Biological Evolution Standard B – 5.2
Standard B-5 The student will demonstrate an understanding of biological evolution and the diversity of life. Indicator B – 5.2: Explain how genetic processes result in the continuity of life-forms over time.
Key Concepts Common genetic structures Passing genetic information Nucleic acids Proteins Passing genetic information Sexual reproduction Asexual reproduction
What You Already Know! In the 6th grade, you summarized the characteristics that all organisms share and differentiated between sexual and asexual reproduction. In the 8th grade, you illustrated the vast diversity of life that has been present on Earth over time by using the geologic time scale.
What You Should Understand After This Lesson Continuity of life-forms on Earth is based on an organism’s ability to pass on genes to the next generation. All life on Earth shares at least two of the same structures: Nucleic acids and proteins All organisms reproduce
Objective Compare sexual and asexual reproduction.
Vocabulary Nucleic acid Protein Sexual reproduction Asexual reproduction
2 Structures Nucleic Acids Proteins
Sexual Reproduction Results in genetically unique offspring. Involves 2 parents with 2 sets of genes. Uses the process of meiosis to create gametes. Crossing over, mutations, and genetic engineering can all lead to variability. Will have a higher chance of survival in a changing environment. Reproduction rate is slow.
Sexual Reproduction
Asexual Reproduction Results in genetically identical offspring. Involves 1 parent, with 1 set of genes. Uses mitosis (binary fission). The only method of achieving genetic variability is through a mutation in the DNA. Respond the same in a changing environment since all are genetically identical. Reproduction rate is relatively high.
Asexual Reproduction