The Nitrogen Cycle

Nitrogen is an essential constituent of animal and plant matter as it forms proteins, which are the building blocks of life. The ultimate source of nitrogen is atmospheric nitrogen but neither plants nor animals are capable of assimilating free nitrogen. Thus the process of converting atmospheric nitrogen to useful nitrogenous compounds by plants, passing it to animals and then the decomposition of these compounds to give back free nitrogen in the atmospheres is called Nitrogen Cycle

The following list of resources will support instruction for the Nitrogen Cycle:

United Streaming

Upon entering the United Streaming site, use the SEARCH engine and enter The Nitrogen Cycle. The first listing will has 8 segments and is an excellent introduction to this section.

1. Campbell Biology 7th Edition-After login, Chapter 37

2. Soil Organisms and the Nitrogen Cycle-General Objective: Understand the role of organisms that live in the soil and the nitrogen cycle.

3. The Nitrogen Cycle Poster and Lab Data

4. Chemistry Tutor-Nitrogen

5. Lab 2 Urban Ecology, Nitrogen Cycling in the Urban Ecosystem by Myrna Hall

6. Windows to the Universe-Nitrogen Cycle Activity

Chapter 10- Molecular Genetics-Objectives

OBJECTIVES

Chapter 10: Molecular Genetics

1. Define and be able to use the following terms in context to answer questions:

a. transcription

b. translation

c. triplet

d. codon

e. anticodon

f. ribosome

g. DNA polymerases

h. RNA polymerases

i. DNA- 3'-5'

j. RNA 5'-3'

k. frame reading

l. introns

m. exons

n. semi-conservative replication

o. template

p. Okazaki fragments

q. lead strand and lag strand

2. What is semi-conservative replication and how does the process occur? What are the steps in the process?

3. What is transcription and how does the process occur? What are the steps in the process?

4. Explain the process of translation. What are the steps in the process?

5. Complete worksheets, and online exercises, that demonstrate the processes of transcription and translation.

*Alternative Objective

1. RNA and DNA structure and function

2. How do the structures of nucleic acids relate to their functions of information storage and protein synthesis?

3. What are the similarities and differences between prokaryotic and eukaryotic genomes?

Gene regulation

4. What are some mechanisms by which gene expression is regulated in prokaryotes and eukaryotes?

Mutation

5. In what ways can genetic information be altered?

6. What are some effects of these alterations?

7. What is the relationship of the nitrogenous bases in DNA to each other in terms of the % composition?

8. What are Okazaki fragments and what is their function in the replication process?

9. What is the basic chemistry of the nucleic acids?

a. What bases do they contain?

b. Categorize the bases as purines or pyrimidines.

c. What types of bonds are holding the bases and the sides of the DNA and RNA molecules together?

d. What elements make up the DNA and RNA molecules?

e. What is the structure and function of a nucleotide?

f. What enzymes service the DNA (replication/transcription) and RNA (transcription/translation) molecules ?

10. How is the coded information organized grammatically and syntactically (direction of read, sequence, triplet, codon, anticodon)?

11. Who are the following individuals and what was their contribution to our knowledge of the DNA molecule?

a. Fred Griffith

b. Hershey and Chase

c. Avery, MacLeod, and McCarty

d. Chargaff

e. Meselson and Stahl

12. How are the designations of 5'-3' /3'-5' important in the operation of the nucleic acids?

13. What is the relationship of DNA, a gene, and a chromosome?

14. How do you decode DNA or mRNA. How is the code organized?

15. What are the differences and variations in the mRNA molecule in a prokaryotic cell and a eukaryotic cell (introns and exons)?

16. How does the process of transcription and translation (initiation-elongation-termination) work?
What is the structure and operation of a ribosome?

17. What is the function of reverse transcriptase in a retrovirus?

18. How bacteria gain antibiotic resistance? How do they inherit that resistance from one another?

19. How does the differentiation of cells occur? What appears to be the mechanism of differentiation?

20. What does the phrase, "the universal DNA code" mean?

21. What is the "central dogma" in molecular biology concerning the role of DNA?

Viral structure and replication

22. What is the structure of viruses?

23. What are the major steps in viral reproduction?

24. How do viruses transfer genetic material between cells?

Nucleic acid technology and applications

25. What are some current recombinant technologies?

26. What are some practical applications of nucleic acid technology?

27. What legal and ethical problems may arise from these applications?

Chapter 10-Homework

"Man is DNA's way of understanding itself."

McGraw Hill Learning Center
Movies, Animations and Interactive Tutorial Links

1. The presentations from the Cold Spring Harbor Lab are the best Tutorials to a fundamental understanding of DNA's history and function. Start here and move through the Concepts and Animations from 15-28 to get the foundation needed to dive into the technical details of DNA Structure and Function.
2. Concepts and Animations 29 through 41-The Cold Spring Harbor site will complete your journey into genetics by carrying you into the application of your knowledge of DNA Structure and Function.

3. DNA: The Next 50 Years
Genetics Education Center
New Scientist:Genetics

On April 25, 1953, James Watson and Francis Crick published their Nobel Prize winning description of the DNA double helix, which spawned over the next 50 years unimaginable medical advances including vaccines, diagnostics, drugs, and the complete sequencing of the human genome.
-April 2003 was a pivotal month in the past, present, and future of genetic medicine:
-50th anniversary of the discovery of DNA's double helical structure
-Completion of the sequencing of the human genome
-National proclamation of April 2003 as "Human Genome Month" and April 25 as "DNA Day."

BIOCOACH ACTIVITIES
DNA Structure and Replication
From Gene to Protein: Transcription
From Gene to Protein: Translation (Protein
Synthesis)
Genetics 621-Principles of Genetic Analysis University of North Carolina
The Human Genome
Cold Spring Harbor - The Dolan Learning Center

Chapter 10-Integrated Technology

Key Tutorials

DNA and Genes
Action Bioscience
Biology Assessment Test Items 2001
Movies, Animations and Interactive Tutorial Links
Molecular Biology Resources
Genetic Science Learning Center

Epigenetics I
-Recent discoveries in the field of epigenetics -- the study of heritable changes in gene function that occur without a change in the DNA sequence -- have blurred the neat picture of mutation and recombination, and are changing the way researchers think about heredity.
- Epigenetic mechanisms such as DNA methylation, histone acetylation, and RNA interference, and their effects in gene activation and inactivation, are increasingly understood to be more than "bit players" in phenotype transmission and development.
-Changes to DNA and its associated proteins can alter gene expression without altering the DNA sequence.
-Chemical modifications to the DNA or the histones alter the structure of the chromatin without changing the nucleotide sequence of the DNA. Such modifications are described as epigenetic.

DNA Tutorial
1. CDs on presentation system
2 Power Point Presentations with lecture
3. Video Presentations
4. Replication-Transcription-Translation Worksheets
5. DNA Workshop-You try it!
6. Cell Biology Animation - Johnny Kyrk
7. Kimball's Pages
a. Chromosomes
b. DNA
c. Replication
(1). The Replication Fork
d. Transcription
e. Translation
f. Mutations
g. Proteasome
h. Operon
i. Transposons:Mobile DNA
j. Ribozymes
8. Animations
Replication of DNA
a. Replication Animation
(1). Replication Animation #2
(2). Replication Animation #3
b. Transcription Animation
(1) Transcription Animation #2
(2) Transcription Animation #3
c. Intitiation-Elongation-Termination Animation
7. Gene Maps
a. Karyotyping Activity
8. Preliminary Findings of the Human Genome Project
5. Genome Biology
9. Introns
a. Introns and Exons
b. Introns:A Mystery
c. Introns-History
10. The Rules of Protein Structure
11. The DNA Files-Audio
12. Jurassic Park Genetics
a. Beyond Jurassic Park:Real Science with Ancient DNA
b. San Diego Natural History Museuem answers questions about Jurassic Park

Chapter 12- Mendelian Genetics Objectives

OBJECTIVES

Chapter 12 Test: Mendelian Genetics

Eukaryotic chromosomes

1.How is genetic information organized in the eukaryotic chromosome?

2. How does this organization contribute to both continuity of and variability in the genetic information?

Inheritance patterns

3.How did Mendel's work lay the foundation of modern genetics?

4. What are the principal patterns of inheritance?

5. What is a Punnett diagram and what does it have to do with dominance, recessiveness, etc.?

6. What are the definitions of the following terms associated with Mendelian genetics and how are they used to interpret problems of inheritance?

P1 generation

F1, F2, etc

.
monohybrid

alleles

dihybrid

dominant

recessive

homozygous

heterozygous

genotype

phenotype

gamete

meiosis

crossing over

pedigree

testcross

phenotypic ratio

genotypic ratio

3:1 ratio

9:3:3:1 ratio

haploid

diploid

Punnett Square

7. What are Mendel's Laws of Segregation and Independent Assortment?

8. How does a backcoss or testcross work and when it is used by breeders?

9. How do the following terms relate to Mendelian genetics?

incomplete dominance

codominance

multiple alleles

polygenic inheritance

10. What is a karyotype ?

11. What are the causes and symptoms of the following genetic disorders?

Down Syndrome

Sickle Cell Anemia

Huntington Disease

Cystic Fibrosis

albinism

colorblindness

hemophilia

12. How is skin color in humans related to polygenic inheritance?

13. What is the diploid and haploid chromosome number in humans?

14. What are the fundamentals of X-linked inheritance?

15. How do you do the following Mendelian crosses andwhat would be their F1 phenotypic ratios?

a. Monohybrid

b. Dihybrid

c. Monohybrid Incomplete Dominance

d. X-linked

e. ABO blood types (Multiple alleles-Codominance)

Mendelian Genetics concepts and Animations 1 through 14

a. What are the genotypes of males and females?

Males XY

Females XX

b. What do the following terms mean and how are they used in genetics problems?
genotype-the types of genes an organism contains
(T-tall, t-short)

phenotype-the physical appearance of an organism as the result of the genotype.
(T genotype-tall phenotype t short phenotype)

c. What is the genetic disease sickle-cell anemia and how is it inherited?

d. What is Down's Syndrome? What is trisomy of chromosome 21?