Genetics Lecture 1 Flashcards
Describe what occurs when the following bacteria are injected into mice. Living non-virulent Living virulent Heat killed non-virulent Heat killed virulent
Living non-virulent Mice lives, no bacteria recovered Living virulent Mice dies, virulent bacteria recovered Heat killed non-virulent Mice lives, no bacteria recovered Heat killed virulent Mice dies, live virulent bacteria recovered
How can transformation and digestive enzymes be used to prove DNA is genetic material?
Use enzymes to digest DNA, lipids, carbohydrates, and proteins one at a time.
Transformation only stops occurring when DNA is digested.
What is Chargraff’s rule?
A=T and G=C
Name the purines.
Adenine and guanine
Name the pyrimidines.
Thymine, uracil, and cytosine
How many rings do purines and pyrimidines have?
Purine - 2
Pyrimidine - 1
What group is present at C2 of DNA and RNA that differentiates them from each other?
DNA - has deoxy
RNA - has hydroxy
Which direction does the DNA chain grow in?
5’ to 3’ direction.
When a nucleic acid chain is being made, where does the phosphate group bind to?
3’ of the previous ribose, and 5’ of the incoming one.
Why are hydrogen bonds ideal for a double helix?
Easy to break, so not much energy required to open and close them.
Name and describe the 3 forms of DNA, including rotation, thickness, and length.
A – right handed, thicker, shorter than B
B – right handed – normal dna
Z – left handed, elongated and thin
What kinds of nucleic acids can viruses be (4)?
dsDNA
ssDNA
dsRNA
ssRNA
Do viruses have a segmented genome or a single chromosome?
Can be either.
Name the T even bacteriophages, and describe their genome structure.
T2, T4, T6
Has dsDNA, single chromosome, and linear
Whats special about the phage λ, and how does it achieve this? What purpose does it serve?
Genome can change from circular to linear and vice versa.
Has complimentary sticky ends to achieve this.
Becomes circular when infecting a host to avoid attack, as its easier to digest linear DNA.
