"From Atoms to Traits" Questions

Explain the significance of Mendel

Mendel’s breading experiment with the peas changed the general perception of heritable genes from blendable to exact genes passed from parents to the offspring. The inheritance patterns of the peas were mirrored by the behavior of chromosomes in the nucleus. Genetic information was finally becoming a physical appearance in the threads inside the nucleus. 

Draw the structure of DNA and who discovered this structure 

James D. Watson and Francis Crick 

Explain each of the five examples of variations that occur to DNA and give an example of each.

1. Point Mutation (Class of Mutation)- A single base pair change. A whipper dog can vary between a small version and a big version of itself. The mutation stops the signaling molecule gene that regulates muscle growth. The muscle growth is uncontrolled because it does not have a stop signal. 
2. Insertion- One or more extra nucleotides are inserted into replicating DNA. In a pea plant there is a base pair sequence that makes peas wrinkled. The inserted base pair stops starch synthesis which then changes the peas’ sugar and water content. 
3. Gene Copy Number- Entire gene is duplicated by copying errors during cell division, leading to differences between species and variation among members. Chimps normally have a single gene for the starch digesting enzyme, whereas humans can have 10 copies of the gene. 
4. Duplication- Sequences that contain the same base pair repeated 8 or more times (homopolymers). A pig’s gene of two additional C-G pairs in a sequence stops the signal in pigment cells, producing a light colored coat. Copying mistakes within cells can cause the sequences to lose bases, letting the gene signal pigment cells and producing dark spots on the pig. 
5. Regulatory- Mutations in the DNA that controls when and where genes are activated that can produce trait alterations by changing the formation of body parts during the organisms development. The shape difference between the teosinte plant and the cornstalk is because the changes in the gene that controls the cell division during stem development. 

What is eve-devo?

Evolutionary development is a field of biology that compares the developments of different organisms to determine the ancestry and relationships between them. It is the understanding of how development is changed over time. 

Make a connection between human migration and the mutation of lactose intolerance. 

The ability to digest milk into adulthood, has arisen independently in groups of different continents. It provides a nutritional advantage to humans and connects to the changes of DNA sequences and human cultural evolution. Example- Mutations affecting the same gene dominate in East African and Saudi Arabian populations who herd milk-producing animals.