BIOLOGY NOTES GENETICS PART 6 PAGES 230 238
BIOLOGY NOTES GENETICS PART 6 PAGES 230 -238
Standards: 4. 9 Describe the basic processes of DNA _____ replication and how it relates to transmission and conservation of genetic information 4. 12 Evaluate the impact of biotechnology on _____ the individual, society, and the environment including medical and ethical issues
Essential Questions: 1. Why is the sequence of nucleotides on DNA molecules so important?
I. Deoxyribose Nucleic Acid (DNA) = the living genetic material that composes all ______ organisms polymers • nucleic acids are highly complex _____ made up of smaller monomer subunits called nucleotides ______ vnucleotide = monomer of nucleic acids sugar a composed of a 5 -carbon ______, base phosphate group, and a nitrogenous ______
DIAGRAM:
sugar in DNA • Deoxyribose is the name of the ______ • DNA has 4 possible nitrogenous bases: 1. Adenine (A) 2. Thymine (T) 3. Cytosine (C) 4. Guanine (G)
2 rings v purine = a nitrogenous base with __ e. g. adenine, guanine 1 ring v pyrimidine = a nitrogenous base with __ e. g. thymine, cytosine
A. DNA Structure 2 • In DNA, nucleotides join together to form ___ long chains which together compose the polymeric nucleic acid • the chains of nucleotides in DNA are joined by _____ hydrogen bonds between the bases ladder shape resulting in a _______ v the chains twist together to form a _______ double helix
• the double helix shape was first discovered in Watson and Francis ______ Crick 1953 by James _______
Chargaff discovered that specific bases • Erwin ____ will pair together in DNA. This became known as Chargaff’s rules and later the principle of base pairing. v base pairing principle = principle that DNA can only form hydrogen bonds in _____ thymine or guanine between adenine and ____ cytosine and _____
DIAGRAM:
B. DNA Sequence • How can organisms be different from each other if their genetic material is made of the same molecules (DNA)? **WORD JUMBLE** sequence of ______ nucleotides in the Answer: the _____ different DNA strands of organisms is _____ sequence of nucleotides forms the • The _____ unique genetic information of an organism. The more closely related two organisms are, the alike the order of nucleotides in their more _____ DNA will be.
• Human Genome Project = research project that led scientists to discover the exact sequence of nucleotide bases for the human _____ species ____ 1990 and completed in _____ 2003 v begun in _____ v documented the exact nucleotide sequence for over __ 3 billion base pairings
C. DNA vs. Chromosome vs. Chromatin • All cells contain DNA v prokaryotic DNA is contained in the cytoplasm of the cell _____ v eukaryotic DNA is contained in the nucleus _______ of the cell
long The nucleus of each • DNA is extremely _____. meter of human cell contains more than 1 ______ DNA. How does it fit? ? ? v histones = proteins inside of the nucleus DNA wraps itself around tightly that _____ v nucleosomes = the beadlike structure formed from several _____ histones wrapped DNA together in _____ Ø when nucleosome are supercoiled but not chromatin is organized in structure, _____ present
Ø when nucleosomes are supercoiled into organized structures that are tightly packed, _______ chromosomes are present
D. DNA Replication replication exact copies of cells • During cell _____, genetic information. are made including all _______ meiosis copies of gametes are During cell ____, made which also include copying of genetic information. v DNA replication = the production of a genetically identical copy of DNA made division prior to cell ____ S phase of interphase Ø made during the ___ (synthesis)
v without replication, a species could not survive and individuals could not successfully _______ grow and reproduce _____ STEPS OF DNA REPLICATION: unwinds and _____ enzymes 1. The double helix ____ break the hydrogen bonds holding together the “unzipping” paired bases. This is known as ______ the DNA. v replication fork = the point at which the 2 chains of DNA are separated ** helicases are enzymes that unwind**
nucleotides in the nucleus bond 2. Free floating ______ base pairing. The to the single strand by _____ complementary added bases are known as _______ bases and the new strands are complementary (mates) ____________ to the original strands. v DNA polymerase = the principle enzyme involved in DNA replication because it bonds bases to the original bases and the free ______ proofreads each new DNA strand. _____
3. Replication continues until all of the DNA in all chromosomes of the cell have been of the _______ 2 copies of the copied. The results are __ organism’s genetic material. 1 original copy of • each new copy consists of ___ 1 new, complementary strand. DNA and ____
QUESTION: What would be the complementary base sequence of DNA for TACGTTC? ANSWER: AT G CAA G ___________________
- Slides: 28