Question

anticipation guide
after completing the lesson, copy and paste your answers from slide 2 into the first two columns. then, in the 4th and 5th columns, put an x in either true or false for each statement. provide evidence for your answer.

true	false	statement	true	false	evidence
		dna is shaped like a triple helix.	x
		a nucleotide consists of a phosphate group, a sugar, and a phosphate base.
		the sides of a dna ladder are made of a pattern of phosphates and sugars.
		there are four possible bases in each dna nucleotide.
		adenine pairs with thymine.
		before dna can be replicated, it must unwind like a zipper. an enzyme makes this happen!
		the nitrogen bases are paired together by covalent bonds.
		enzymes called dna helicase reads the dna templates and builds a new strand based on base - pairing rules.
		the two strands of dna created during dna replication are called semiconservative.

Explanation:

1. "DNA carries the genetic information in an organism." - True. DNA contains genes which code for proteins and other cellular functions, storing genetic info. Evidence: Fundamental concept in genetics.
2. "DNA is shaped like a triple helix." - False. DNA is a double - helix structure. Evidence: Watson - Crick model.
3. "A nucleotide consists of a phosphate group, a sugar, and a phosphate base." - False. A nucleotide has a phosphate group, a sugar (deoxyribose in DNA), and a nitrogenous base. Evidence: Definition of nucleotide structure.
4. "The sides of a DNA ladder are made of a pattern of phosphates and sugars." - True. The sugar - phosphate backbone forms the sides of the DNA double - helix. Evidence: DNA structure.
5. "There are four possible bases in each DNA nucleotide." - True. The bases are adenine (A), thymine (T), guanine (G), and cytosine (C). Evidence: DNA base composition.
6. "Adenine pairs with thymine." - True. Adenine forms two hydrogen bonds with thymine in DNA base - pairing. Evidence: Chargaff's rules and DNA base - pairing.
7. "Before DNA can be replicated, it must unwind like a zipper. An enzyme makes this happen." - True. DNA helicase unwinds the DNA double - helix for replication. Evidence: DNA replication process.
8. "The nitrogen bases are paired together by covalent bonds." - False. Nitrogen bases in DNA are paired by hydrogen bonds. Evidence: DNA base - pairing nature.
9. "Enzymes called DNA helicase reads the DNA templates and builds a new strand based on base - pairing rules." - False. DNA polymerase reads the DNA template and builds a new strand. DNA helicase only unwinds the DNA. Evidence: DNA replication enzymes' functions.
10. "The two strands of DNA created during DNA replication are called semiconservative." - True. In semiconservative replication, each new DNA molecule has one old strand and one new strand. Evidence: Meselson - Stahl experiment.

Answer:

True	False	Statement	True	False	Evidence
	X	DNA is shaped like a triple helix.			Watson - Crick model
	X	A nucleotide consists of a phosphate group, a sugar, and a phosphate base.			Definition of nucleotide structure
X		The sides of a DNA ladder are made of a pattern of phosphates and sugars.			DNA structure
X		There are four possible bases in each DNA nucleotide.			DNA base composition
X		Adenine pairs with thymine.			Chargaff's rules and DNA base - pairing
X		Before DNA can be replicated, it must unwind like a zipper. An enzyme makes this happen.			DNA replication process
	X	The nitrogen bases are paired together by covalent bonds.			DNA base - pairing nature
	X	Enzymes called DNA helicase reads the DNA templates and builds a new strand based on base - pairing rules.			DNA replication enzymes' functions
X		The two strands of DNA created during DNA replication are called semiconservative.			Meselson - Stahl experiment