Reflections: Weeks 0 and 1

Greetings, and welcome to my weekly BI311 blog summaries for students! I will be posting these on Friday afternoons for the rest of the term. These summaries will provide some basic reflections on the material covered over the previous week, as well as a sneak peek at information that will be presented the following week. I encourage everyone to take the few minutes to read through these blog posts to help learn and understand material presented in lecture. There will NEVER be material found only in the blog that will appear on the midterms and final. Rather, the blog summaries serve to supplement and provide a different ‘voice’ for the material covered during lectures, recitations, and in the homework. Enjoy!

Week 0 and 1 Reflections: In the first few lectures we reviewed DNA basics, with special emphasis on its features that make it an effective molecule for heredity (replication) and coding biological functions (transcription and translation, for example). There was also a strong emphasis on some of the basic laboratory techniques (restriction analysis, agarose gels, PCR, terminator-based DNA sequencing) used by scientists to study genetic processes – it will be important to have a strong understanding of these methods: what each one achieves, and how each one works. These methods will repeatedly come up throughout the course as we discuss more and more about genetic processes. We also started down the path of understanding the logic of genetic analysis in understanding biochemical pathways, including complementation testing. This sort of analysis underpins many genetic studies and the conceptual logic is very important to understand. In recitation, you got to know Sulochana and brushed up on some important concepts and terminology. These early lectures were meant to mostly be review – covering key concepts and topics that I will presume students know and understand as we move forward in the class.

Week 2 Sneak Peek: We will quickly review material from Chapter 1.3 on Monday, and then switch focus to the fundamental processes of transmission genetics that were revealed by Gregor Mendel’s famous pea plant experiments. Chapter 2 is very foundational – important to make sure you understand the concepts presented here to succeed in this class.

Answers: Quiz 1

Correct answers in bold.

1. (5 points) Which of the following is NOT a property associated with DNA?

a. double helix

b. sugar-phosphate backbone

c. parallel strands (5’ to 3’)

d. nucleic acids


2. (5 points) The process by which a polypeptide (or, protein) is produced from a template RNA molecule is referred to as:

a. replication

b. translation

c. transcription

d. reverse transcription


3. You have been given a tube containing a DNA sample. The DNA is linear and 1,000 base pairs (bp) in length. To further study this DNA, you decide to use the restriction enzyme PvuII and agarose gel electrophoresis. The diagram in the box below shows how PvuII digests DNA molecules, with the arrowheads indicating strand cleavages sites.

Part A. (5 points) Which of the following terms best describes the ends of DNA molecules that result after digestion with PvuII?

a. Blunt-ended

b. Sticky-ended

c. Terminated

d. Replicated

Part B. (5 points) After performing the restriction digestion of your DNA sample with PvuII and running an agarose gel, you observe three bands on the gel: 50 bp, 450 bp, and 500 bp. How many recognition sites for PvuII are present in your original linear DNA sample? Write the answer in below.


Answers: Homework 1

Chapter 1

1.10: 5’-ATGAC-3’


1.18: A) Met-Ser-Thr-Ala-Val-Leu-Glu-Asn-Pro-Gly. B) This mutation alters the start codon into a non-start codon. Thus, translation will not start with the first AUG; translation would start with the next AUG down the mRNA, or not at all if it is too far down the molecule. C) Met-Ser-Thr-Ala-Val-Leu-Glu-Asn-Pro-Gly (no change). D) The Val is changed into an Ala. E) Met-Ser-Thr-Ala-Val-Leu.

1.19: There are 64 possible codons and only 20 amino acids; hence, many amino acids are specified by two or more codons. A mutation that changes a codon for a particular amino acid into a synonymous codon for the same amino acid does not change the amino acid sequence.

1.20: a) Y, Z and W missing, X in excess; b) Z and W missing, Y in excess; c) W missing, Z in excess


Chapter 6

6.1: Each fragment terminates with a single-stranded overhang whose base sequence is complementary to that of any other fragment produced by the same restriction enzyme.

6.10: The DNA in this species is replicated by a totally conservative mechanism, where the parental strands stay together and the daughter strands stay together.



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PCR Video

Today in class, we will focus a lot on experimental methods for studying DNA in the lab.  One major technique we will explore is the polymerase chain reaction (PCR).  We will watch a video in class; am posting it here too in case students want to review the video.  Enjoy!

Kakapo genomes!

Thanks to BI 311 student Morgan Olson for sharing this great story about sequencing New Zealand parrot (kakapo) genomes, all 153 of them 🙂

You can see the story here:

Welcome to BI311 Genetics!

Greetings and welcome to my Genetics blog for BI 311 students!

I will create blog posts once per week, usually on Friday afternoons.  The blog will serve three main functions:

  1. Weekly Reflections: These posts will offer short plain-language summaries of the material covered over the previous week, as well as a sneak peek at information that will be presented the following week.
  2. Genetics in the News: It’s an exciting time in the world of genetics!  These posts will highlight recent research findings and big news related to genetics.
  3. Answers: The answer keys to weekly homework problems and pop quizzes will be provided in blog posts.

I encourage everyone to take the few minutes to visit the blog once or twice a week to help learn the material presented in lecture. There will NEVER be content found only in the blog that appears on midterms and the final.  Rather, the blog serves to supplement and provide a different voice for material covered during lectures, recitations, and in the homework.