Unit 4- Part 2HeredityStandard B-4: The student will demonstrate an understanding of the molecular basis of

heredity.

Indicator B – 4.1: Compare DNA and RNA in terms of structure, nucleotides, and base pairs.

Key Concepts:Nucleic Acids: deoxyribonucleic acid (DNA), ribonucleic acid (RNA)Nucleotides: nitrogen base, sugar, phosphate groupComplementary base pairs

It is essential for you to know: Nucleic acids are organic molecules that serve as the blueprint for proteins and, through the

action of proteins, for all cellular activity. The two types of nucleic acids: DNA and RNA DNA and RNA are both comprised of nucleotides that each have three parts. The basic structure of DNA and RNA are different (due to their sugars). DNA is double stranded whereas RNA is single stranded.

Objectives:Compare DNA and RNA. Recognize the chemical names of the DNA and RNA molecules. Identify the three parts of a nucleotide. Interpret an illustration of a nucleotide. Interpret an illustration of a DNA and a RNA molecule.

Vocabulary Words:Define the following vocabulary words in the space provided.

1. Bacteriophage

2. Nucleotide

3. Double helix

4. Base pairing rules

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Discovery of DNA

The scientist ____________ ____________ did a

series of experiments on bacteria that caused the

sickness ____________.

He discovered a process called ____________.

Did he know

exactly what

was

transforming?

In 1944, ___________ _____________ repeated Griffiths work.

He wanted to determine which molecule in the bacteria was actually

transforming.

He discovered that ________ was the transforming principle that Griffith had

noticed.

Conclusive evidence that DNA was

the transforming principle came in

1952 from two American

biologists, ____________

___________ and _____________

_____________. They studied

___________, which are

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viruses that affect bacteria by

taken over their DNA.

Structure of DNADNA stands for _________________ _______________.

The picture to the right is a ___________. It is composed of

3 parts:

______________

______________

______________

The only difference between nucleotides within a DNA molecule are its nitrogen-containing bases.

Therefore, there can be _______ different nucleotides within DNA.

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DNA has to be responsible for three things in living things:

1.

2.

3.

The backbone of the DNA molecule is formed by

___________ and __________.

The “rungs” of the DNA molecule are composed of

the ____________ __________.

What do you notice about the arrangement of the

DNA molecule that makes it a uniform width?

The bonds found within the DNA molecule are

different. Label the bonds in the picture to the

right.

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Scientists Who’s Work Contributed to the Identifying the Structure of DNA

_____________ ______________ discovered that in any sample of DNA, the amount of

___________ = __________ and the amount of ____________ = ______________. This is known as

the rules of base pairing. Because of this, the DNA molecule always maintains a uniform

__________.

In the early 1950s, ______________

____________ used x-ray diffraction to

get information about the structure of

DNA. She suggested it was __________

in nature.

_____________ ______________ and ______________

_______________ built the first model of DNA. They used

Franklin’s pictures to help them construct it. They ultimately

discovered that DNA was actually a __________

__________.

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In the space below, sketch a DNA molecule. Make it 3 bases in length.

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Structure of RNA RNA stands for _______________ ________________.

The picture to the right is a ___________. It is composed of

3 parts:

______________

______________

______________

The only difference between nucleotides within a RNA molecule are its nitrogen-containing bases.

Therefore, there can be _______ different nucleotides within RNA.

What do you immediately

notice as a difference

between the bases of RNA

and DNA?

The rules of base-pairing still apply in RNA:

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___________ = _____________

____________ = ____________

RNA is single stranded instead of double stranded like DNA.

There are three types of RNA:

1.

2.

3.

RNA is made from DNA in a process called _____________.

DNA RNA

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Heredity

Standard B-4: The student will demonstrate an understanding of the molecular basis of heredity.

Indicator B – 4.3 : Explain how DNA functions as the code of life and the blueprint for proteins. We will focus on DNA replication in this standard.

Indicator B – 4.4: Summarize the basic process involved in protein synthesis (including transcription and translation).

Key Concepts:DNA ReplicationProtein SynthesisTranscription: messenger RNA (mRNA)Translation: ribosomal RNA (rRNA), codons, transfer RNA (tRNA), anticodon site, peptide bond, stop codon

It is essential for you to know: The specificity of proteins is determined by the order of the nitrogenous bases found in the

DNA. DNA can function as the code of life for protein synthesis or the process of DNA replication,

which ensures that every new cell has identical DNA. DNA replication is carried about by a series of enzymes. Transcription is the process by which a portion of the molecule of DNA is copied into a

complementary strand of RNA. Translation is the process of interpreting the genetic message and building the protein and

begins when the mRNA attaches to a ribosome, which contains proteins and ribosomal RNA (rRNA), in the cytoplasm.

Objectives:Summarize the role of DNA as the code of life. Summarize the process of DNA replication. Interpret illustrations of the processes of transcription, translation, and protein synthesis. Compare the processes of transcription and translation. Sequence the steps of transcription and translation. Explain the significance of each step to the overall process of protein synthesis.

Vocabulary Words:Define the following vocabulary words in the space provided.

1. Replication

2. DNA polymerase

3. Central dogma4. RNA

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5. Transcription

6. RNA polymerase

7. Messenger RNA (mRNA)

8. Ribosomal RNA (rRNA)

9. Transfer RNA (tRNA)

10.Translation

11.Codon

12.Stop codon

13.Start codon

14.Anticodon

15.Peptide bond

*******************************************************************************************************************DNA Replication

The double helix structure explains how _________________can occur.

The two strands of DNA are _______________. This means one strand can be used to make a

__________ of the other strand.

Before a cell can fully divide, the ________ must first be copied:

The two strand of the DNA ___________.

Two new complementary strands are made via ________ __________.

This occurs during ___ phase of the cell cycle.

In ________ DNA replication starts at one point in

the chromosome and proceeds in two directions until

the entire chromosome is replication.

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In __________, DNA replication starts at hundreds of places along the chromosome and proceeds in either direction until the entire chromosome is copied.

Enzymes first “________” the old strands of DNA.

This process involves a lot of proteins/enzymes.

The primary enzyme involved is _____ ___________.

PRACTICE/REVIEW1. What would be the complimentary DNA strand to the

following nucleotide sequence?

A T C C G A T T A G G C C C A T A C G

2. What is the first step in DNA replication?

3. What enzyme matches the bases of free nucleotides to the bass on the parent strand?

4. If the DNA double helix were a twisted ladder, what would the sides be composed of?

5. If the DNA double helix were a twisted ladder, what would the rungs be composed of?

6. Fill in the following chart.

Nucleotide Base Abbreviation Complementary BaseT

CA

G

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In living things, there is a one way flow of information from DNA Proteins. This is called Central Dogma. Proteins are made in essentially two main steps:

Transcription

Translation

Transcription___________ is the process of copying DNA into RNA.

So that translation can happen next.

Happens in the _________ of eukaryotes and the

____________ of prokaryotes.

Wherever the ______ is.

The enzyme _______ ________ binds to DNA at promoter

regions & separates the strands. It then uses one strand of

DNA as a _________ to make RNA. The RNA made is

actually _________.

Uses base-paring:

A=U G=C

Transcribe the following DNA strands:A – G – G – T – A – C – C – C – G – A – A – T – T - T

G – G – C – C – A – A – T – T – A – A – T – T – G – C

Once the mRNA is formed, it will leave the nucleus (of a eukaryote) and go the ribosome, where the

second part of protein synthesis takes place, ______________.

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TranslationProteins are made (____________) by joining amino

acids into long chains called ___________.

This is called ____________ _____________.

The language of mRNA is called the ___________

____________.

Comprised of the letters A, U, C and G

Every combination of three letters is called a

_________.

The genetic code (one is example is show to the

right) is read _______ letters at a time. These _____

letters are referred to as a ________.

Underline the codons in the following strand of mRNA: UCGCACGGU

What amino acids do those codons code for? ____________ ------- ___________ ------___________

The bonds that link amino acids together are called ________ ________.

How many possible codons are there in the genetic code? ___________

What is the “Start Codon”? ____________ What amino acid is it? _________________

What are the 3 “Stop Codons”? ________, ___________, ________

Figure out the amino acid sequence coded for by the following DNA: TACGCATGGAAT

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How does translation actually occur?There are many steps to the actual process of translation. The process of translation actually

One major molecule in this occurs on the _________.:

process is the ________ molecule:

mRNA is made from ________

mRNA comes out of the __________

and attaches to a ____________.

__________ brings in an ____________

that is complementary to the mRNA codon sequences. With each __________ is the

_________ _________ that the mRNA codon codes for.

*Codon is AUG, the anticodon is UAC bringing methionine with it to attach to mRNA.

__________ chain grows until it reaches a stop codon.

Heredity

Standard B-4: The student will demonstrate an understanding of the molecular basis of heredity.

Indicator B – 4.8: Compare the consequences of mutations in body cells with those in

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gametes.

Indicator B – 4.9: Exemplify ways that introduce new genetic characteristics into an organism or a population by applying the principles of modern genetics.

Key Concepts:Mutation:

mutagen, mutant cell, gene mutation, chromosomal mutation, nondisjunctionBeneficial mutationsPedigreeGenetic Engineering:

gene map, genome, cloning, gene therapy, stem cellsSelective Breeding:

Inbreeding, hybridization

It is essential for you to know: A mutation is an alteration of an organism’s DNA and can range in severity. Most mutations are automatically repaired by the organism’s enzymes, but those that are not

repaired may result in altered chromosomes or genes. Mutant body cells are not passed on to offspring but mutant gametes may be inherited. In some cases, mutations are beneficial to organisms. A pedigree is a chart constructed to show an inheritance pattern within a family through

multiple generations. Genetic engineering is the process of replacing specific genes in an organism in order to

ensure that the organism expresses a desired trait. Cloning, gene therapy, and hybridization are applications of genetic engineering.

Objectives:Compare the consequences of mutations in body cells with those in gametes. Recall the causes of mutations. Classify mutations as resulting from sex cell or somatic cell alterations.Classify mutations as genetic or chromosomal. Exemplify genetic or chromosomal disorders. Interpret a pedigree with regard to the nature of specific traits within a family. Exemplify ways that introduce new genetic characteristics into an organism or a population. Recognize types of genetic engineering and selective breeding. Summarize the purposes of the various types of genetic engineering and selective breeding. Compare selective breeding and hybridization. Summarize the benefits & drawbacks of the types of genetic engineering & selective breeding.

Vocabulary Words:Define the following vocabulary words in the space provided.

1. Mutation

2. Point mutation

3. Frameshift mutation14

4. Mutagen

5. Clone

6. Genetic engineering

7. Recombinant DNA

8. Transgenic

9. Genomics

10.Human Genome Project

11.Gene therapy

12.Artificial selection (selective breeding)

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MUTATIONSIn the space below, write an example of a mistake that you have made in your life.

________________________________________________________________________________

________________________________________________________________________________

Mistakes are common. Some turn out good while others turn out not so good. Mutations are the same. Some mutations result in a negative aspect, while others turn out to be advantageous to the organism.

Mutation:

Mutations can occur in many ways:

Mutations may or may not be passed to offspring. It depends on the type of cell.

Mutations in Gametes Mutations in Somatic Cells

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There are two types of mutations: _____________ mutations and __________________ mutations

Gene MutationsThe two types of Gene Mutations are Point and Frameshift.

Chromosomal MutationsThe four types of Chromosomal

Mutations are Deletion,

Duplication, Inversion and

Translocation.

Nondisjunction is when

homologous chromosomes fail to

separate during meiosis.

___________ ______________ may arise from mutations in sex cells (gametes).

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Monosomy or Trisomy Disorders

Klinefelter’s Syndrome in males

Turner Syndrome in females

Down Syndrome in males or females

Are all mutations bad?

In some cases mutations are ______________ to

organisms. ________________ ______________ are

changes that may be useful to organisms in different

changing environments. These mutations result in

phenotypes that are favored by natural selection and

increase in population. An example may be

______________________________________.

PedigreesBy examining a ____________, geneticists can identify the

likelihood of an individual inheriting a genetic disorder. It is a chart constructed to show

the ___________ pattern of a disorder within a family over multiple generations.

Why are there not more mutations?

______________ are factors such as radiation, chemicals, UV light, etc. that can

cause changes in DNA. Some are natural and others are man-made. 17

Genetic Engineering

Since ALL living things use _______ as their genetic material, it is possible

to __________ DNA from one species to another, either through a cross if

the organisms are of the same species, or through ____________

_________ if the organisms are dissimilar.

____________ ______________ is the

process of ___________ specific genes in an organism in order

to ensure that the organism ______________ a desired trait.

Genetic engineering is accomplished by taking specific genes

from one organism and placing them _______ another

organism.

Genetic

engineering can only occur when scientists

know __________ where particular genes

for particular traits occur on specific

chromosomes.

○ A ______ ______ shows the

relative location of each known gene on a chromosome.

○ __________ refers to all the genetic material in an organism. The Human Genome Project

that _________ the DNA sequence of human genes is useful in ____________ genes for

specific traits.

In __________, an identical copy of a gene or an entire

organism is produced. Cloning brings ___________ such

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as organ transplants or saving endangered species, but it may also result in an organism with genetic

disorders or health problems.

In______ ________, scientists insert a normal gene into an absent or ________ gene. Once

inserted the normal gene begins to produce

the ________ protein or enzyme, eliminating

the

cause of the __________. However, gene

therapy has had limited success because the

host often rejects the injected genetic

material.

_______ _______ are undifferentiated

cells that have the potential to become

specialized in

structure or function. Primarily found in

_________, they are also found all over

the adult

human body (for example bone

marrow) but may be harder to isolate.

Therapy using stem

cells can replace tissue that is

deficient due to disease or damage.

Results of genetic engineering may include:

○ Plants that manufacture natural insecticides, are higher in protein, or spoil more slowly.

○ Animals that are bigger, are faster growing, or are resistant to disease.

○ Bacteria that produce hormones such as human insulin or human growth hormone.

○ In humans, it is theoretically possible to transplant copies of normal genes into the cells of

people suffering from genetically carried diseases such a Tay-Sachs disease, cystic fibrosis,

and sickle-cell anemia.

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Selective Breeding

____________ __________ is the method of ___________ selecting and breeding only organisms

with a desired trait to produce the next generation. Almost all domesticated animals and most crop

plants are the result of selective breeding.

Once the breeder has successfully produced offspring with the desired set of characteristics,

_____________ (crossing individuals who are closely related) continues.

○ The drawback to this method is that ____________ gene defects often show up more

frequently after several generations of inbreeding.

_______________, which is another form of selective breeding,

is the choosing and breeding organisms that show strong

expression for two different traits in order to produce offspring

that express both traits.

Recombinant DNA

___________ ____________ is taking the genes

out of one organism and placing them in the

genome of another in order for that organism to

express that gene. This method is often ________ than selective breeding and only requires ______

generation. Also, the results are more predictable.

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Genetically Modified Foods___________ __________ foods are foods that have been ___________ altered. Foods that are

NOT genetically modified are considered _____________, meaning they are natural.

One good thing about GM foods is:

A bad thing about GM foods is:

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