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OBJECTIVE SHEET NUCLEIC ACIDS AND PROTEIN SYNTHESIS 1. Name the four bases in DNA and describe the structure of DNA. 2. Describe the steps involved in DNA replication. Include in your discussion

helicase, DNA polymerase, complementary base-pairs, anti-parallel, semi-conservative replication.

3. Describe three uses for recombinant DNA (rDNA). Use restriction enzymes on

a bacterial plasmid and human gene to form a recombinant plasmid with “sticky-ends”.

4. Construct a plasmid and insert a human gene for insulin using restriction

enzymes and DNA ligase. 5. Compare and contrast DNA and mRNA in regards to structure, function, and

location in the cell. 6. Outline the basic steps of protein synthesis. Identify the role of DNA, mRNA,

tRNA and ribosomes in the processes of transcription and translation. Include in your discussion transcriptase, tRNA, codon, anti-codon, polypeptide.

7. Determine the sequence of amino acids coded for by a specific DNA sequence

given a table of mRNA codons or tRNA anticodons. 8. Give examples of environmental mutagens that can cause mutation in humans. 9. Use examples to explain how mutations in DNA affect protein synthesis and

may lead to genetic disorders. 10. Distinguish between chromosomal mutations and gene (point) mutations. 11. Explain sex-linked diseases and the problems with phenotypic cures.

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Karyotypes A picture of a chromosome will reveal distinct

bands at various locations. These bands help biologists identify locations of specific genes called “loci”. The banding pattern and size of the chromosome helps biologists determine which of the 23 pairs of chromosomes they are looking at. Arranging the chromosomes in order is called a karyotype. Karyotypes can reveal many genetic properties of an individual.

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Reading Assignment Nucleic Acids Answer on a separate sheet of paper. 1. Read pages 501 to 505. Pay close attention to any diagrams. 2. State Chargaff’s rule. 3. What contribution did Rosalind Franklin make? 4. Who finally worked out the structure of DNA? 5. What does 5´(5 prime) and 3´(3 prime) refer to? 6. Draw a section of a DNA molecule that contains 4 different bases. Label the

following on your diagram: 5´- 3´ and the 3´- 5´ direction of the two strands of DNA. Label the hydrogen bonds, purine bases, pyrimidine bases, deoxyribose, phosphate group.

7. What is meant by anti-parallel? 8. What does it mean when biologists say that during DNA replication, there is

“semi-conservative replication”. Fill in the following blanks on this page: 9. ___________________ opens the DNA molecule by breaking _________ bonds between the bases. This separates the DNA into __________________ Complementary ___________________________ then occurs adding new _____________________ to the exposed ones by ____ bonds. The base Thymine always bonds with _________________ and guanine always bonds to __________________. The enzyme _____________________ is responsible for adding new nucleotides as well as a ___________________ to ensure that there are no mistakes or ________________________ made.

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10. If normal DNA containing non-radioactive N14 was placed into a solution with radioactive N15 and allowed to divide once. Then the N15 is removed and replaced with N14 and allowed to divide one more time. a) How many DNA helixes are present? How many daughter cells will form? b) How many of the new DNA strands will be radioactive? c) How many of the new cells will be radioactive? d) When does DNA replication occur?

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Nucleic Acid Exercise Replication, Transcription, Translation

DNA makes up the chromosomes of all cells. It contains the genetic information that enables a cell to carry on its life activities as well as to reproduce. RNA is smaller copy of a single section of DNA that carries DNA’s message out to the cytoplasm. Your group will need to follow the instructions in each of the three parts of this exercise very carefully.

Start by reading about the DNA molecule on page 504.* A. The Composition of DNA In humans, DNA is a large molecule made up of about 6 billion smaller molecules called nucleotides. Each nucleotide is composed of three parts: a base (either guanine, cytosine, thymine, or adenine), a phosphate group, and a sugar called deoxyribose. You are going to build a small section of DNA using paper models. From the envelopes provided, go and get the following paper nucleotides: 8 cytosine, 8 guanine, 4 thymine, and 4 adenine. Clear off your table and arrange the nucleotides below vertically on your desk by linking them together. These will represent the “left side” of the DNA molecule:

cytosine thymine guanine adenine guanine cytosine A1. Name the 2 molecules that alternate to form the outside “rail” A2. Name the molecule to which each base is attached. A3. Name the molecules that form the “half-rungs of the ladder”. Now use some of the extra molecules that you have to match the left side of the DNA on your desk. You will form a full ladder with 6 pairs of nucleotides. From now on, you can use “A” to represent adenine, “C” for cytosine, etc. A4. Name the base pairings in your model. A5. If the left side of DNA is A T T C G G C T, what will the right side be? A6. What do you notice about the deoxyribose molecules when you compare the left side to the right side?

Start by reading pg. 506 * B. DNA Replication You should remember a little about mitosis from grade 11. In mitosis, the parent cell divides to form 2 identical daughter cells. The doubling of the DNA occurs during prophase. This doubling of DNA is called DNA Replication. You are going to use your paper model of DNA to see how this occurs in the nucleus of cells. Split your DNA molecule from part A down the middle into a left and right side. Add new complementary nucleotides to each side.

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B1. How many DNA “ladders” do you have now? B2. How do these ladders compare to each other? B3. How do these ladders compare to the original DNA ladder? B4. How does base pairing ensure that the DNA is copied correctly? B5. What would happen to the cell once it has 2 copies of DNA in its nucleus? B6. What enzymes are used in DNA Replication?

Start by reading pages 506-508 * C. mRNA Transcription To control the cytoplasm, DNA must get its message out of the nucleus. The problem is that DNA is too large a molecule to pass through the nuclear membrane. This forces it to make a small copy of itself called mRNA to carry the DNA’s instructions bit by bit to the cytoplasm. Each “bit” is actually a single gene from the DNA. The making of a molecule of mRNA is called Transcription. A section of DNA that performs a certain job in the cell is called a gene. Each gene acts by building a molecule of mRNA. Open one of your DNA helixes. Keep the “right side” and put the other DNA nucleotides back into their correct envelope. (please!) Go get the following mRNA nucleotides from the other 4 envelopes (that say RNA): 2 guanine, 1 adenine, 2 cytosine, and 1 uracil. Check to make sure that your paper nucleotides all say ribose instead of deoxyribose. Make sure that you have the correct nucleotides. Match these up with the right side of your existing DNA molecule. In a real cell, this mRNA strand that you have would leave the nucleus and carry a copy (a gene) of the DNA’s message to the cytoplasm. C1. What is the difference between ribose and deoxyribose? *(use text) C2. If DNA has the bases A T T C G G C A, what will be the order of mRNA bases? C3. List 3 structural differences between a DNA and a mRNA molecule. C4. How is it ensured that the same mRNA molecule always is formed from the same section of DNA? C5. Write out the full and correct names for DNA and RNA. C6. Explain in point form how Transcription occurs. Include all necessary enzymes.

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D. Translation Names: _______________ Blk: _______ You will remember that DNA builds a complementary mRNA molecule in transcription. If we follow this mRNA molecule out of the cytoplasm, we can learn how this molecule directs the production of a protein by the cell in a process called translation. 1. A strand of mRNA nucleotides has the sequence U U A U C A

mRNA codons (groups of 3) are read at the ribosome. What were the DNA nucleotides complementary to these codons?

____________________________ 2. Read the description of tRNA in your text page 509 before proceeding. How

many bases form the anti-codon sequence? ______ 3. What would be the order of tRNA bases that pair with the mRNA in question 1? _____________________________ Each tRNA acts like a taxi and can carry only 1 specific passenger. This passenger is an amino acid. By varying the order of these amino acids, different proteins result. Read the given information:

Amino Acid tRNA anti-codon Serine AGU Proline GGG Leucine AAU Glutamic acid CUU Tyrosine AUA Arginine GCU Glutamine GUU Phenylalanine AAA Valine CAA Lysine UUU

4. A protein consists of the following amino acid sequence: leucine, glutamine,

tyrosine, leucine, serine. What would be the sequence of tRNA molecules responsible for forming a protein with AA in this order?

______________________________________________________ ______________________________________________________

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5. A ribosome obtains the following mRNA message: A A A C G A G A A G U U. What will be the sequence of tRNA anti-codons joining the mRNA? _____________________________ 6. What will be the order of the amino acids from question #5? ______________________________________________________ 7. What would be the sequence of the DNA molecule that originally coded for

these amino acids? ______________________________ 8. Hemoglobin (a blood protein) has 600 amino acids. How many bases long is

the gene that directs its production? ______________ 9. How does a mutation in DNA appear as a protein error? ______________________________________________________ 10. A section of DNA was found to be composed of 42% Guanine. Predict the

amounts of the following in the remainder of the DNA section:

A= C= U= T= Use page 507 in your text to fill in the table.

___ ___ ___

___ G ___

___ ___ ___

___ ___ C

DNA strand

#1 A ___ G

C ___ ___

___ ___ T

___ ___ ___

DNA strand

#2 A ___ ___

___ ___ ___

___ ___ ___

___ ___ ___

mRNA

___ A ___

___ ___ U

___ ___ ___

___ ___ ___

tRNA

___________

__________

valine

serine

Amino acid name

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Continuity and Change Paradoxically, DNA has to provide for the stability of the species by accurately reproducing a new individual, while at the same time it has to be the source of mutations to keep “looking” for the best organism to fit into a changing environment. Summary of Protein Synthesis 1. In the nucleus, helicase opens the DNA molecule in the area of the gene that is to be

transcribed. 2. Transcriptase starts hydrogen bonding the new RNA nucleotides to the exposed DNA nucleotides. mRNA is complementary to DNA. 3. The making of mRNA is called Transcription. Each sequence of three bases is called a codon since it will code for an amino acid. 4. The mRNA molecule is released from the DNA. The DNA closes. 5. The mRNA leaves the nucleus out a nuclear pore and becomes associated with a ribosome. A ribosome has two binding sites where tRNA molecules can H bond to the mRNA. 6. As a tRNA arrives carrying a specific amino acid at the ribosome, it H bonds to the first 3 mRNA bases on the first binding site of the ribosome using its 3 bases. These are called an anti-codon. 7. A second tRNA arrives carrying its amino acid passenger and H bonds to the mRNA

on the second binding site on the ribosome. A peptide bond forms between the two amino acids.

8. Now the ribosome moves along the mRNA the space of 1 codon. The first tRNA leaves

and the second tRNA slides over into the first binding site. A third tRNA arrives and fits into the second binding site. This process of going from the “language of codons” to the “language of amino acids” is aptly called Translation. This process repeats itself until a “stop” codon is reached on the mRNA. More ribosomes may already be copying the mRNA. The three parts of translation are initiation, elongation and termination. Read about this on pages 510-511 of your text.

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Matching: Replication/Transcription Match the term with the phrase. (check your answers up front) _____ Chargaff’s rule 1. single ring base _____ Crick/Watson 2. won Nobel prize for DNA structure _____ pyrimidine 3. A-T C-G _____ DNA Polymerase 4. length of DNA governs a trait _____ RNA Polymerase 5. has two binding sites _____ ribose 6. a nucleotide triplet _____ transcription 7. guanine, adenine _____ deoxyribose 8. provides a site for protein synthesis _____ nucleotide 9. phosphoric acid, 5 carbon sugar, base _____ gene 10. 1 less oxygen in its sugar _____ ribosome 11. process of copying a gene _____ complementary base pair 12. found only in mRNA _____ codon 13. also known as Transcriptase 14. Hershey-Chase 15. A-G C-T 16. cytosine, guanine 17. same number of A’s and T’s 18. occurs only in the nucleus 19. proof reads a new DNA strand

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Recombinant DNA (rDNA) reference pg. 526 Many bacteria contain plasmids, small independent DNA fragments that carry specific pieces of genetic information, such as resistance to specific antibiotics or other genetic characteristics. Plasmids can be transmitted from one bacterium to another, or from the environment into a host bacterium, in a process called transformation. Plasmids can also incorporate into their DNA sequence pieces of DNA from different organisms. Plasmids that incorporate new DNA are called recombinant plasmids. Recombinant plasmids are used in biotechnology to carry DNA that codes for substances, such as human insulin or growth hormone, into bacteria. Bacteria that contain the recombinant plasmids can then be grown commercially to provide the needed substance. Special enzymes, called restriction enzymes, can cut DNA fragments from almost any organism. Typically, restriction enzymes are used to cut DNA molecules into individual genes. There are many different restriction enzymes, each of which recognizes one specific nucleotide sequence. Many restriction enzymes work by finding palindrome sections of DNA (regions where the order of nucleotides at one end is the reverse of the sequence at the opposite end). These two complementary ends are called “sticky ends”.

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This way a restriction enzyme can cut tiny sticky ends of DNA (complementary ends) that will match and attach to sticky ends of any other DNA that has been cut with the same enzyme. DNA ligase joins the matching sticky ends of the DNA pieces from different sources that have been cut by the same restriction enzyme. Once a desired DNA fragment has been isolated and cut with a specific restriction enzyme, the sticky ends of both the desired DNA fragment, and from a plasmid that has been cut by the same restriction enzyme, can be joined together, forming a recombinant DNA plasmid. Special plasmids, which have antibiotic resistance markers, are used in this process so that a researcher will be able to tell that the desired DNA has been incorporated into the target plasmid and subsequently into the host bacterium. In this exercise, you will simulate the process of forming a recombinant plasmid using paper models. The gene of interest has been identified on the cell DNA template, and the isolated plasmid template has a number of antibiotic resistance genes. You must find an appropriate restriction enzyme that can cut the gene of interest out of the cell DNA and splice it into the plasmid using the matching sticky ends of DNA cut by the selected enzyme. You will also discuss how you might use antibiotics to determine if a host bacterium has successfully incorporated the recombinant plasmid. Materials Required for Each Person in your Group · plasmid sheet (blue paper) · tape · restriction enzyme sheet (pink paper) · scissors · Cell DNA sheet (green paper) Procedure 1. Construct a Plasmid: The blue sheet is made up of strips representing segments of the bacterial plasmid DNA. Cut the plasmid strips out along the dotted lines and tape the strips together in any order you choose as long as they are all in the same direction. When the strips are connected, take the two free ends and tape them together forming a circle with the nucleotides facing out. (Be sure that the ends do not overlap covering any of the nucleotides.) The plasmid that has been chosen also has genes that code for antibiotic resistance. Bacteria that incorporate such antibiotic resistant plasmids become resistant to those antibiotics. These resistance "markers" are useful in identifying bacteria that successfully incorporate desired recombinant plasmids. Note the location of the antibiotic resistance sites (variously shaded) on the plasmid, as well as the location of the plasmid replication site. The key for these sites is at the bottom of the plasmid paper sheet. 2. Assemble the Human Cell DNA: Cut out the strips of the cell DNA from the green sheet. The strips are numbered 1– 6. Tape the strips together in numeric order forming one long nucleotide sequence strip.(do not make a loop) This long Cell DNA strip contains the protein gene (human insulin), which is shaded, that will be transferred to the bacterial plasmid.

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3. Restriction Enzyme "Cards": Cut out the pink enzyme sheet along the thick dotted lines to form the "cards" that simulate the restriction enzymes. Each card has a segment of nucleotide base pairs that represents the code recognized by that specific restriction enzyme. Use a pencil to draw the fine dotted lines on each card to match page 20 from your manual. 4. Locate the Enzyme Restriction Sites on the Plasmid: Compare the sequences of base pairs on each of the enzyme cards with the nucleotide (base pair) sequences on the circular plasmid. Mark the places on the plasmid in pen or pencil that are identical with the code pairs of the restriction enzymes. These are locations where the enzyme can cut the plasmid. Notice the cut pattern illustrated by the dotted lines on the enzymes. Note: Not all of the restriction enzymes may have matches with the plasmid. You may set aside any enzyme cards that do not match; they cannot be used in this exercise. 5. Locate the Restriction Sites on the Cell DNA: Using only the enzymes that had matches on the plasmid, locate and mark restriction sites for each of the enzymes on the Cell DNA. The enzyme must have a match in two places on the Cell DNA: one above the human insuli gene and the second below the human insulin gene to be useful. Discard any pink enzyme card that cannot cut the Cell DNA both above and below the insulin gene. Select one of the remaining pink enzyme cards that can cut the plasmid in one place and the cell DNA in two places. Ideally, you would choose the enzyme that can cut closest to the insulin gene on both sides, so that less "extraneous" cell DNA will be transferred to the plasmid. The same enzyme must be used to make the cut in the plasmid and the two cuts on the Cell DNA molecule that removes the human insulin gene to be inserted into the bacterial plasmid. 6. Make your recombinant bacterial plasmid: Notice the fine dotted line from the pink enzyme card you have selected. Line-up the restriction enzyme to the complementary plasmid site and cut the plasmid along the restriction site marked by the dotted lines on the enzyme. This cut forms the "sticky ends" characteristic of restriction enzymes, and facilitates the splicing of the Cell DNA into the plasmid. Repeat this process with the cell DNA at the restriction site above the insulin gene, and at the restriction site below the insulin gene. Once you have made your cuts, insert the insulin gene into the plasmid by matching the "sticky ends" of the insulin gene with the "sticky ends" of the plasmid and fastening the ends together with tape. Your recombinant plasmid should be circular with a portion of the Cell DNA included. 7. Locate the antibiotic resistant sites on the recombinant plasmid, along with the replication site. If you spliced the Cell DNA gene into the middle of the plasmid replication site, the plasmid will not be able to replicate, and cannot be of use. In a similar fashion, any antibiotic resistant sites that were destroyed will not work.

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rDNA Plasmid Questions (Answer on a separate piece of paper in complete sentences with the title RECOMBINANT PLASMID). 1. How many enzymes did you end up using? Which ones? 2. What is the difference between a bacterial chromosome and a plasmid? 3. What is a gene in molecular terms? 4. What benefits do plasmids offer to bacteria? (Give two examples.) 5. In what way do these endonucleases (restriction enzymes)cut the DNA? What is the

significance of this way to rDNA technology? 6. What amino acid sequence does the gene inserted code for? (Review protein synthesis and write the full amino acid sequence for the inserted human insulin gene using pg. 507 text. Use the LEFT side of the gene’s DNA) 7. In what ways is bacterial transformation useful to humans? Provide as many examples as you can find. 8. Assume you have added your recombinant plasmid culture to a new culture of bacteria with none of the resistance genes in biotechnology lab. Some of the new bacteria cells will integrate the new resistance genes and others will not. How would you use antibiotics to identify which bacteria have incorporated the recombinant plasmid so they can be commercially grown to produce the substance being coded for by the gene? By looking at your recombinant plasmid, which antibiotics would you use to test this? To hand in: · your carefully constructed recombinant plasmid · the restriction enzyme(s) that was used to prepare the recombinant plasmid · answers to the questions on a separate sheet of paper Clip all three items together with your names and block number.

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BACTERIAL PLASMID

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

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

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

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

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

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

ampicillin resistance kanamycin resistance tetracycline resistance plasmid replication

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HUMAN CELL DNA

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

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

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

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

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

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

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

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

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

1 2 3 4 5 6

human insulin gene

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RESTRICTION ENZYMES

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Mutations Reference text pg. 490-91 Mutations are changes in the DNA code. They are random and are not always dangerous. Germinal mutations are those that occur in the sperm or egg and are passed on to the next generation. Somatic mutations are those that occur in an individual, but not in gametes.

Types of Mutations A. Chromosomal Mutations Inversion: a piece breaks off and Translocation: an exchange of joins in the wrong order. of pieces between non-partner

chromosomes.

Deletion: loss of a piece Duplication: a piece gets copied B. Gene of Point Mutations These involve only a few nucleotides within a gene, and are usually more serious than chromosomal mutations. Deletion – a nucleotide is left out and may cause a non-functioning protein. Substitution- one nucleotide replaces another. Ie: Sickle Cell Anemia Addition- an extra base gets put in. Follow the example on the board for gene mutations. Relate this concept to how gene mutations are a direct result of a problem during protein synthesis.

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Causes of Mutations Anything that causes a mutation is called a mutagen.

Drugs (LSD, cocaine, tobacco, alcohol)

Chemicals (food additives, pesticides)

Radiation

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Genetics The Study of Heredity Characteristics appear to be repeated from generation to generation. The passing of traits from parents to offspring is called heredity. Your biological traits are controlled by your genes located on the chromosomes found in your cells. You inherited half of your 46 chromosomes from your mother and the other half from your father. You are therefore referred to as a diploid organism. Genes Are units of nucleotide base pairs located on the chromosomes which provide instructions to a cell to produce a specific trait. You have about 22,000 genes (ie. the gene that produces insulin). Many genes can interact with other genes to produce various effects. Alleles Are two or more alternate forms of a gene. An allele for black hair or blonde hair are forms of the gene for hair colour. In genetic problems, alleles are represented with letters. Dominant Allele These alleles determine the expression (the way you look) of the genetic trait. Recessive Allele These alleles are masked by the dominant allele and are only expressed when the dominant allele is not present for that gene. Genotype Refers to the genes (we use letter combinations) for an organism. ie (BB, Bb, bb) Phenotype Refers to the way the genotype physically appears in an organism. Homozygous Refers to a genotype in which both alleles of a pair are identical. ie (RR, aa) Heterozygous Refers to a genotype in which the alleles of a pair are different. ie (Rr, Aa) Incomplete Dominance When two alleles interact and are equally dominant, they produce a new phenotype which is a blending of the two traits. ie (a red flower crosses with a white flower to produce blended offspring: pink flowers) Codominance Both alleles are expressed at the same time producing a mottled effect. ie (red and white flowers make flowers with red and white specks)

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All of your body cells contain a full complement of 46 chromosomes. (23 pairs) These cells are referred to as somatic cells with autosomal chromosomes. The male sperm cell or the female ova (egg) are called gamete cells with sex chromosomes and are the only cells to contain only ½ of this number. A gene for a particular trait can be found on one of your chromosomes. The location of a gene on a chromosome is called the gene’s loci. One allele comes from your father while the other comes from your mother. During the formation of gametes, the alleles will segregate (separate) to ensure that each gamete cell has only one of the alleles for that trait. Because of this independent assortment, a male’s sperm may contain the allele for blue eyes while another of his sperm may carry the allele for brown eyes. The female’s egg that gets fertilized by the sperm may also contain an allele for either blue or brown eyes. Both gametes carry the gene for eye colour and both gametes have only one allele (form) of the gene. When fertilization is complete, the first somatic cell is created. This cell is called a zygote. The zygote has a full 46 chromosomes (23 pairs)

This was you on day 1 aren’t you cute

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Genetics Review: Alleles: B= brown eyes, b=blue eyes, XX= female, XY=male, R= tongue roller r=flat tongue Give the genotype of the following: if there is not enough information to determine an answer, put a __?__ on the blank. a) heterozygous brown-eyed male = ______________________________ b) a tongue rolling female = ______________________________ c) a homozygous brown eyed person who can’t roll tongue = ______________ d) a brown-eyed person heterozygous for tongue rolling = ________________ Give the phenotype of the following: a) BBXY ______________________________________________ b) rrXX ______________________________________________ c) BbrrXY ______________________________________________ Write out the F1 generation when a heterozygous tall plant crosses a dwarf plant. Use T = tall and t = dwarf for alleles. What are the chances of getting a blue-eyed person who cannot roll their tongue if you cross a heterozygous brown-eyed tongue roller with a blue-eyed heterozygous roller? Show the F1 generation to determine your answer.

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Sex-Linked Traits Reference text pgs. 492-94 Body characteristics that are carried on the X and Y chromosome are called “sex-linked traits” because they are passed from parent to offspring on the sex chromosomes. Female chromosome Male chromosome To set up a key to do Punnett squares for sex-linked traits, males and females must be indicated: XC = normal vision All the possible genotypes include: Xc = colour blindness XCXC = normal female XCXc = normal female (carrier) Males have a 1/2 chance XcXc = colour blind female Females have a 1/3 chance XCY = normal male XcY = colour blind male Most sex-linked traits occur on the X chromosome simply because of the size of the X compared to the smaller Y chromosome.

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Do the following practice problems and check up at the front desk: Colour Blindness: A female carrier for colour blindness has children with a normal vision male. What are the chances of a colour blind daughter? If they have a son, what are the chances he will be colour blind? Show the F1 generation. Hemophilia: XH = normal clotter Xh = bleeder A male who can normally clot has kids with a female (the female’s dad is a hemophiliac and her mom is not even a carrier). Determine their chances for a hemophiliac daughter or son. Show the F1 generation.

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OBJECTIVE SHEET TISSUES AND HOMEOSTASIS 1. Identify 4 types of tissues found in the human body. 2. Observe 3 types of muscle tissue under the microscope. Include skeletal, smooth, and cardiac muscle. Sketch each type and identify the characteristics unique to each kind. 3. Observe a long bone and identify the periostium, compact bone, spongy bone, the locations of red marrow and yellow marrow. 4. Observe a slide of ground bone under the microscope. Identify and explain the role of Haversian systems (Osteon), Haversian canal, matrix, cannaliculi, concentric lamellae, lacuna, osteocytes, osteoblasts, and osteoclasts. 5. Explain how the body maintains homeostasis using feedback loops. 6. Describe how the human body regulates body temperature using a feedback loop.

Muscle Tissue?

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Tissue Types protective – covers sensory – receptors glandular - secretes connective tissue loose (supports organs) adipose energy storage, insulation dense connective tendons (muscle to bone) ligaments (bone to bone) cartilage bone blood smooth skeletal cardiac neurons

neuroglial cells – support and nourish, bind and insulate neurons.

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Human Tissues Observe the following microscope slides, wall charts and artifacts. Connective Tissue Examine the prepared slide of ground bone (H). Diagram an Osteon/Haversian System to include the Haversian canal, canaliculi, and the lacuna containing the osteocyte (bone cell). Read the text on connective tissue (reference pg. 197)

Long Bone Diagram a long bone to include spongy bone (contains red marrow that makes RBC). Identify the compact bone. Identify the marrow cavity (contains yellow marrow for fat storage). Label the periosteum. (reference pg. 368) Skeleton Label the skeleton diagrams provided. Learn the parts of the skull. Go over the bones on the human skeleton. Compare these parts to the other skulls provided.(reference pg. 369,372) Muscle Tissue Examine the three types of muscle slides under high power: cardiac (heart) striated (skeletal) and smooth muscle. Diagram a section of each in your notebook. You do not need the magnification of your drawing. To draw smooth muscle, you need to view the x.s. slide of the cat intestine. Look at the Digestive System chart and compare the circular muscle layer (which is the smooth muscle) to your slide of the cat intestine and draw the smooth muscle. Draw a few spindle-shaped cells of circular muscle. Write a short note under your drawings describing the characteristics unique to each type of muscle. (reference pg.199) The Cat Intestine ileum or jejunum (similar layers to human) View the slide of the x.s. of duodenum. Draw a pie-shaped section to include: the lumen, the mucosa with villi, the submucosa containing blood vessels and the lymph nodes, the circular muscle (smooth muscle), the longitudinal muscle and the serosa. Find the wall chart on epithelial tissue. Find and read the wall chart on the Digestive System. (reference pg. 194,217)

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Skull Bones

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OBJECTIVE SHEET THE DIGESTIVE SYSTEM

1. Identify and give a function for each of the following:

Mouth duodenum

Tongue liver

Teeth gall bladder

Salivary glands pancreas

Pharynx small intestine

Epiglottis appendix

Stomach large intestine (colon)

Pyloric sphincter rectum

2. Describe where the following digestive enzymes are produced. Describe their optimal pH they like to operate at and identify the substrate and product that they promote:

Salivary amylase

Pancreatic Amylase

Protease (pepsin and trypsin)

Lipase

Nuclease

Peptidase

Maltase

3. Describe swallowing and peristalsis.

4. Identify the components and describe the digestive actions of gastric juice, pancreatic juice and intestinal juices.

5. Identify the source gland for and describe the function of insulin.

6. Explain the role of bile in the emulsification of fats.

7. List six major functions of the liver.

8. Examine the small intestine and describe how it is specialized for digestion

and absorption of nutrients.

9. Identify the role of the following digestive hormones: gastrin, secretin, cholecystokinin (CCK), GIP (enterogastrone)

10. Describe the functions of E. Coli in the colon.

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HORMONE GLAND STIMULUS FOR

RELEASE

TARGET ACTION

GASTRIN

SECRETIN

CCK (cholecystokinin)

GIP (enterogasterone)

The 5 major layers of the digestive tract

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The Hepatic Portal System

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Digestion Practice Review: Digestive System When swallowing, the ___________________ covers the opening to the larynx. The ______________________ takes food to the stomach, where ______________________ (chemical/physical) digestion is started. The products of digestion are absorbed into the cells of the __________________ which are finger-like projections of the mucosal wall. Three Accessory Glands The pancreas sends digestive juices to the ___________________________ which is the first part of the small intestine. After eating, the liver stores glucose as _______________________. The gall bladder stores ______________ a substance that ______________________ fat. Digestive Enzymes In the mouth, salivary glands digest starch into ______________________. Pancreatic juice contains _______________________ for digesting protein. Another kind of enzyme in the pancreas called _______________________ digests starch and ____________________________ for digesting fat. Digestive Hormones Three main hormones play an important role in digestion. The hormone Gastrin Is produced by the __________________________ when the presence of _____________________ is detected. Gastrin enters the blood and increases the activity level of the gastric glands. GIP (gastric inhibitory peptide) otherwise known as ___________________________ works opposite from gastrin and is produced by the wall of the _______________________________.

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Cells of the duodenal wall also produce two other hormones. ______________ and _______________________. Partially digested protein and fat in the duodenum stimulate the release of ________ and the presence of HCl acid stimulates the release of ____________________________. These two hormones increase the output of secretions by these two accessory glands, the ___________________________ and the ______________________.

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Explain why test tubes 1,2, and 3 have the results above. ______________________________________________________ ______________________________________________________ ______________________________________________________

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Test 2 Practice Review 1. Describe the structure of DNA. 2. List the structural differences between DNA and RNA. 3. State the function of the following: tRNA, mRNA, DNA, and rDNA. 4. Explain how a mistake in the DNA code ends up with an improper protein. Include all proper terms and locations. 5. Describe two gene mutations and two chromosomal mutations. 6. List three uses for rDNA. Why are there restriction enzymes in nature? 7. What is a plasmid? Why are restriction enzymes and DNA Ligase important when discussing rDNA technology? 8. Fat digestion can be considered two processes: a physical and a chemical breakdown. Outline the organs and secretions involved in these two processes. 9. Explain the role/significance of the following in digestion: HCO3, HCl, mastification, CCK, emulsification, smooth muscle, villi, accessory glands, and mucosa. 10.If an individual were exposed to a liver toxin such as a weed killer, the liver would gradually stop functioning. An individual may live for as long as 3 days without a functioning liver. Using 5 examples, explain the problems that this individual would have now that their liver is no longer functioning. 11. Describe how the intestine and the villus are structurally modified to carry out their function. 12. Name the four types of tissue. 13. Use a negative feedback loop to explain how the body responds to either high or low body temperature. 14. List the differences among smooth, skeletal, and cardiac muscle. 15. Identify three types of bone cells. 16. Describe how carbohydrates are digested and absorbed in the human digestive system. 17. Identify structures W to Z below and indicate how molecule A is formed. Describe where molecule A enters after it is formed.

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