UNIT 6 AP BIO EXAM REVIEW
QUESTIONS AND ANSWERS
TOPIC 6.1 DNA and RNA Structure - Correct Answers -ENDURING
UNDERSTANDING: Heritable information provides for continuity of life.
LEARNING OBJECTIVE
IST-1.K Describe the structures involved in passing hereditary information from one
generation to the next.
ESSENTIAL KNOWLEDGE
IST-1.K.1 DNA, and in some cases RNA, is the primary source of heritable information.
IST-1.K.2 Genetic information is transmitted from one generation to the next through
DNA or RNA—
a. Genetic information is stored in and passed to subsequent generations through DNA
molecules and, in some cases, RNA molecules.
b. Prokaryotic organisms typically have circular chromosomes, while eukaryotic
organisms typically have multiple linear chromosomes.
IST-1.K.3 Prokaryotes and eukaryotes can contain plasmids, which are small extra-
chromosomal, double-stranded, circular DNA molecules.
LEARNING OBJECTIVE
IST-1.L Describe the characteristics of DNA that allow it to be used as the hereditary
material.
ESSENTIAL KNOWLEDGE
IST-1.L.1 DNA, and sometimes RNA, exhibits specific nucleotide base pairing that is
conserved through evolution: adenine pairs with thymine or uracil (A-T or A-U) and
cytosine pairs with guanine (C-G)—
a. Purines (G and A) have a double ring structure.
b. Pyrimidines (C, T, and U) have a single ring structure.
What is the significance of this famous experiment (what does it demonstrate)? -
Correct Answers -the Hershey-Chase experiments were a series of experiments
conducted in 1952 by Alfred Hershey and Martha Chase that helped to confirm that
DNA is genetic material. While DNA had been known to biologists since 1869, many
scientists still assumed at the time that proteins carried the information for inheritance
because DNA appeared to be an inert molecule, and, since it is located in the nucleus,
its role was considered to be phosphorus storage. In their experiments, Hershey and
Chase showed that when bacteriophages, which are composed of DNA and protein,
infect bacteria, their DNA enters the host bacterial cell, but most of their protein does
, not. Hershey and Chase and subsequent discoveries all served to prove that DNA is the
hereditary material.
How did Crick, Watson, Franklin and Wilkins contribute to our knowledge of DNA? -
Correct Answers -Combined, they revealed the double helix structure of the DNA
molecule.
Draw a plasmid. Where are plasmids found in Prokaryotic cells? Where are they found
in Eukaryotic cells (HINT consider the evolution of some Eukaryotic organelles!)? -
Correct Answers -Plasmids are small rings of DNA free floating inside Prokaryotes.
They are also found in mitochondria and chloroplasts (consider the Endosymbiotic
Theory that these organelles were once free-living prokaryotes)
Come up with some way to remember (to link the facts together) that A and G are
Purines and have a double ring, while C, T, and U are Pyrimidines and have just one
ring. Then share your idea with someone and see what idea they came up with! -
Correct Answers -A and G got married and have 2 wedding rings
C, T, and U build pyramids with one ring
Briefly explain in your own words how the base pairing rules of DNA lead to its ability to
be used as the hereditary material of life (aka, to be copied and passed to a resulting
daughter cell). - Correct Answers -The base pairing rules for DNA are governed by the
complementary base pairs: adenine (A) with thymine (T) in an A-T pairing and cytosine
(C) with guanine (G) in a C-G pairing. Conversely, thymine only binds with adenine in a
T-A pairing and guanine only binds with cytosine in a G-C pairing.
A always matches with T, and G always matches with C.....but why?
Proofreading enzymes run along the DNA molecule to be sure there are no mis-pairings
between bases, but how do they know when a mistake has happened? - Correct
Answers -complementary bases
Consistent pairings of complementary bases allow cells to make double-stranded DNA
from a single strand template, create messenger RNA from DNA and synthesize
proteins from individual amino acids by matching nucleotides bases on messenger RNA
with their complementary bases on transfer RNA.
DNA proofreading is an essential phenomenon during the synthesis of new DNA
strands because if there is a misincorporation of any nucleotide, it will cause mutation
and ultimately damage the cell's cellular processes. Thereby, the cell keeps track of any
misincorporation of nucleotide with the help of the enzyme DNA polymerase.
Based on their structure (shape) explain why purines must always match with
pyrimidines. In your explanation, include how a proofreading enzyme would identify a
location where two purines are accidentally matched up, and a location where two
pyrimidines are matched up. - Correct Answers -Purines pair with pyrimidines because
their size and shape make them a perfect fit for hydrogen bonding
QUESTIONS AND ANSWERS
TOPIC 6.1 DNA and RNA Structure - Correct Answers -ENDURING
UNDERSTANDING: Heritable information provides for continuity of life.
LEARNING OBJECTIVE
IST-1.K Describe the structures involved in passing hereditary information from one
generation to the next.
ESSENTIAL KNOWLEDGE
IST-1.K.1 DNA, and in some cases RNA, is the primary source of heritable information.
IST-1.K.2 Genetic information is transmitted from one generation to the next through
DNA or RNA—
a. Genetic information is stored in and passed to subsequent generations through DNA
molecules and, in some cases, RNA molecules.
b. Prokaryotic organisms typically have circular chromosomes, while eukaryotic
organisms typically have multiple linear chromosomes.
IST-1.K.3 Prokaryotes and eukaryotes can contain plasmids, which are small extra-
chromosomal, double-stranded, circular DNA molecules.
LEARNING OBJECTIVE
IST-1.L Describe the characteristics of DNA that allow it to be used as the hereditary
material.
ESSENTIAL KNOWLEDGE
IST-1.L.1 DNA, and sometimes RNA, exhibits specific nucleotide base pairing that is
conserved through evolution: adenine pairs with thymine or uracil (A-T or A-U) and
cytosine pairs with guanine (C-G)—
a. Purines (G and A) have a double ring structure.
b. Pyrimidines (C, T, and U) have a single ring structure.
What is the significance of this famous experiment (what does it demonstrate)? -
Correct Answers -the Hershey-Chase experiments were a series of experiments
conducted in 1952 by Alfred Hershey and Martha Chase that helped to confirm that
DNA is genetic material. While DNA had been known to biologists since 1869, many
scientists still assumed at the time that proteins carried the information for inheritance
because DNA appeared to be an inert molecule, and, since it is located in the nucleus,
its role was considered to be phosphorus storage. In their experiments, Hershey and
Chase showed that when bacteriophages, which are composed of DNA and protein,
infect bacteria, their DNA enters the host bacterial cell, but most of their protein does
, not. Hershey and Chase and subsequent discoveries all served to prove that DNA is the
hereditary material.
How did Crick, Watson, Franklin and Wilkins contribute to our knowledge of DNA? -
Correct Answers -Combined, they revealed the double helix structure of the DNA
molecule.
Draw a plasmid. Where are plasmids found in Prokaryotic cells? Where are they found
in Eukaryotic cells (HINT consider the evolution of some Eukaryotic organelles!)? -
Correct Answers -Plasmids are small rings of DNA free floating inside Prokaryotes.
They are also found in mitochondria and chloroplasts (consider the Endosymbiotic
Theory that these organelles were once free-living prokaryotes)
Come up with some way to remember (to link the facts together) that A and G are
Purines and have a double ring, while C, T, and U are Pyrimidines and have just one
ring. Then share your idea with someone and see what idea they came up with! -
Correct Answers -A and G got married and have 2 wedding rings
C, T, and U build pyramids with one ring
Briefly explain in your own words how the base pairing rules of DNA lead to its ability to
be used as the hereditary material of life (aka, to be copied and passed to a resulting
daughter cell). - Correct Answers -The base pairing rules for DNA are governed by the
complementary base pairs: adenine (A) with thymine (T) in an A-T pairing and cytosine
(C) with guanine (G) in a C-G pairing. Conversely, thymine only binds with adenine in a
T-A pairing and guanine only binds with cytosine in a G-C pairing.
A always matches with T, and G always matches with C.....but why?
Proofreading enzymes run along the DNA molecule to be sure there are no mis-pairings
between bases, but how do they know when a mistake has happened? - Correct
Answers -complementary bases
Consistent pairings of complementary bases allow cells to make double-stranded DNA
from a single strand template, create messenger RNA from DNA and synthesize
proteins from individual amino acids by matching nucleotides bases on messenger RNA
with their complementary bases on transfer RNA.
DNA proofreading is an essential phenomenon during the synthesis of new DNA
strands because if there is a misincorporation of any nucleotide, it will cause mutation
and ultimately damage the cell's cellular processes. Thereby, the cell keeps track of any
misincorporation of nucleotide with the help of the enzyme DNA polymerase.
Based on their structure (shape) explain why purines must always match with
pyrimidines. In your explanation, include how a proofreading enzyme would identify a
location where two purines are accidentally matched up, and a location where two
pyrimidines are matched up. - Correct Answers -Purines pair with pyrimidines because
their size and shape make them a perfect fit for hydrogen bonding
