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GENETICS

GENETICS. AIM: Why is Genetics a major topic in Science today?. DO NOW:. What do you remember about genetics? List key terms that come to mind…. GENETICS. The branch of human Biology that deals with inheritance.

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GENETICS

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  1. GENETICS

  2. AIM: Why is Genetics a major topic in Science today? DO NOW: What do you remember about genetics? List key terms that come to mind….

  3. GENETICS The branch of human Biology that deals with inheritance Often referred to as the science of heredity and variation in living organisms.

  4. TWO MAJOR DIVISIONS OF GENETICS Mendelian Genetics & Modern Genetics

  5. Mendelian Gentics • Founded by Gregor Mendel • Developed the basic concepts of heredity by applying knowledge of inheritance of characteristics Modern Genetics • Currently being studied today • Seeks to understand the mechanisms( reasons/modes) for inheritance

  6. DNA and its Structure • DNA stands for Deoxyribonucleic acid • Located in the nucleus of each cell. • Role: to maintain genetic continuity and carry all genetic info of the cell Video

  7. Aim: How are genetic traits passed from parent to offspring? • DN: • What is an organelle – give an example. • What is an active site? What is it specific to? • Which reproductive structure is responsible for the “exchange of materials” between mother and fetus? • What type of molecule is capable of mutating? • HW: Review book pages 50-51 q’s 23-31

  8. Chromosomes: package DNA

  9. DNA: • Code of Life • Housed in nucleus • Controls all cell activities • Is replicated when passed from one generation to the next or when cells divide (mitosis) So Who Figured out DNA?

  10. The structure of DNA was discovered by two scientist known as Watson and Crick. How would you describe a DNA molecule?

  11. A DNA MOLECULE LOOKS LIKE A TWISTED LADDER. • This Twisted ladder structure is known as a double helix.

  12. Job Description of DNA • Must store information • Must be “copy-able” • Must be strong and stable • Must be capable of mutating, or changing, slightly to produce variation – which leads to evolution

  13. Some History… • Mendel performed experiments on pea plants • Discovered “Genes” are located at a specific area on a chromosome. • Alleles two genes associated with a specific trait – (one from mom, one from dad)

  14. Aim: How are genetic traits passed from parent to offspring? • DO NOW: Review book p 9 #20-35 • Homework: Castle learning “Genetics 1 & 2”

  15. DNA • is a polymer (large molecule) made up of repeating chemical units called nucleotides.

  16. Nucleotide • Composed of three separate subunits: • Phosphate group • Deoxyribose: 5 carbon sugar • Nitrogenous bases: Adenine (A) Thymine (T) Guanine (G) Cytosine (C)

  17. What is a gene? • A gene • Is a section of the DNA molecule that codes for the production of a specific protein. • Determines characteristics of the organism. • Inherited gene

  18. What are Genes? • Genes = code language for protein, and proteins give you your physical traits • A chromosome contains many genes • A gene is made up of lots of DNA. Put the following terms in order from Big----------------Small: Nucleus, Cell, DNA, Genes, Chromosomes

  19. An Allele Can Either be: • Dominant the expressed allele • CAPITAL LETTER • Recessive  the covered up allele (unless both alleles are recessive) • lowercase letter

  20. TRAITS

  21. Are You Colorblind? Let's Test Your Ability to See Colors?

  22. Phenotype physical traits (observable) an organism has • Genotype  the actual alleles (genes) an organism has • Homozygous person has two identical alleles for a particular trait (TT or tt) (“purebred”) • Heterozygous  person has two different alleles for a particular trait (Tt) (“hybrid”) • Polygenic Inheritance a trait controlled by two or more genes (ex. Eye color, skin color, blood group)

  23. Summary of Genetics: • During fertilization there is random recombination of traits from each parent Random separation and distribution of paired chromosomes occurs during • cleavage • mitotic cell division • fertilization • meiotic cell division

  24. Two genes for two same traits located on the different chromosome are said to be • homozygous • independently assorted • mutagenic agents • linked

  25. The diagram below represents the organization of genetic information within a cells nucleus. • The circle labeledZ most likely represents a.) chromosomes b.) amino acids c.) vacuoles d.) molecular base Nucleus Z Genes

  26. 4 Nitrogenous Bases • Adenine • Thymine • Guanine • Cytosine

  27. Base Pair Rule: • Adenine(A) bonds to Thymine (T) • A-T or T-A • Guanine (G) bonds to Cytosine (C) • G-C or C-G • DNA Chains are COMPLEMENTARY

  28. Practice

  29. More Practice: If a DNA chain consists of the sequence ATTACGGCA What is its complementary sequence?

  30. Answer… TAATGCCGT

  31. When Can You Best See Your Chromosomes? • During Mitosis – all DNA is tightly coiled for accurate cell division!

  32. What is DNA Replication? • Process that creates an exact copy of DNA before a cell divides.

  33. DNA Replication • Start with an original “template” • Untwist “template” • Template “unzips” by DNA Polymerase (enzyme) breaking hydrogen bonds that hold bases together • Free-floating bases in nucleus attach to exposed bases • Result two identical double strands – each made up of one ‘old’ and one ‘new’ strand

  34. DNA unwinds, unzips and base pairs match up.

  35. DNA Replication

  36. Remember: Untwist Unzip Add the Bases Re-Twist! Do the Dance :)

  37. Aim: How do the DNA and RNA molecule differ? Do Now: Which of the following arrangements lists the structures from largest to smallest? a chromosome a nucleus a gene • gene - chromosome - nucleus • gene - nucleus - chromosome • nucleus - gene - chromosome • nucleus - chromosome - gene

  38. A researcher recently discovered a new species of bacteria in the body of a tubeworm living near a hydrothermal vent. He compared the DNA of this new bacterial species to the DNA of four other species of bacteria. The DNA sequences came from the same part of the bacterial chromosome of all four species. • species I • species II • species III • species IV According to these data, the unknown bacterial species is most closely related to

  39. RNA - RiboNucleicAcid • nucleotides • ribose instead of deoxyribose • Uracil(U) instead of Thymine (T) • 3 types • messenger (mRNA) • carries info from DNA • transfer (tRNA) • carries amino acids • ribosomal (rRNA)

  40. DNA vs. RNA

  41. DNA vs. RNA

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