Who Was Gregor Mendel?
Who was Gregor Mendel? What did he do to lay the intellectual foundation of modern genetics? In the following passage, you will be introduced to the basics of Mendelian genetics. As you read the passage, take some notes on the terms and concepts that were central to Mendel's work. After you have finished the reading, complete the crossword puzzle below in order to test your knowledge.
Reading Assignment 7: Mendel's Principles of Inheritance
Read pages 194-196 in the Foundations of Modern Biology Textbook, Solomon, Berg, and Martin's Biology.
Ready for a Review?
Your Personal Journal (Entry 15)
After you have finished reading the excerpt, answer each of the questions below in your journal. Use the TCQC Short-Answer Response Format.
Questions to Open Discussion:
- What is a true-breeding organism? What is a hybrid? What happens when two hybrids mate with each other?
- Why were pea plants such good experimental subjects for Mendel? What seven characters did he study in pea plants?
- What does the term phenotype mean? Use the concept of phenotype to define what a true-breeding organism is.
- What is a gene? What is an allele? Stem height in pea plants may be either tall or short. When a true-breeding tall plant is mated to a true-breeding short plant, all the offspring are tall. Describe this situation using the terms trait, gene, phenotype, dominant allele, and recessive allele.
- For a given trait, an organism has two alleles. During sexual reproduction, the organism passes one of those two alleles on to its offspring (there's a 50% chance that it could be either). The offspring receives one allele from each parent. This is the principle of segregation. Therefore, how might probability have a role in heredity?
- When did Mendel begin his experiments? When did he publish them? When did Darwin publish Origin of Species? Could Darwin have known about Mendel's experiments? How might Darwin have reacted to Mendel's findings?
Now, with your mentor, discuss each question. After your discussion, add any comments to your answers, so that you have fully answered each question. Make sure you feel comfortable with the topics and the vocabulary of this section before you continue.
Want some additional practice? Visit the Cave Spring Middle School Web site "Genetics: Practice Quiz" found on page 7 of the Mentor Guidelines Web site.
Your Personal Journal (Entry 16)
While much of the early work in evolution was inspired by studying plants and animals in the wild, genetics has its roots in the study of domesticated organisms, or organisms that have adapted to living within human society. We are surrounded by domesticated organisms. Think about what you did during the past week.
- How many domesticated plants and animals did you encounter? Describe as many of them as you can.
- What are some differences between domesticated organisms and wild organisms?
