4. DNA and GENETICS

5. DNA Structure
Draw and label a diagram of a DNA molecule from memory.

6. Did you include… Sugar Phosphate Nitrogen base
Complementary base pairing (A-T and G-C)
Double stranded
Double helix

8. Draw one nucleotide from memory.

10. Function and Structure
Made of repeating nucleotides (subunit of nucleic acids)
Sugar-phosphate backbone with hydrogen bonds weakly attaching nitrogen bases (ACTG)
Sequence of nucleotides is the blueprint for you
Changes in sequence of base pairs (mutations) can be good, bad, or neutral and are the ultimate source of evolution

11. Complementary Base Pairing
Write the complementary strand:
ACTTAACCGGATTCCATG

12. ACTTAACCGGATTCCATG TGAATTGGCCTAAGGTAC

13. Chargaff’s Rule %A = %T and %G = %C Why?
If a DNA sample has 30% A and 20%G, how much %T and %C?
G=15% C= T= A=

14. DNA REPLICATION DNA strands are separated and unwind
Original strands serve as template
Free floating nucleotides attach to complementary base pairs
Enzymes involved
“Semi-conservative” model: each resulting DNA molecule has one original/parent strand and one new/daughter strand

15. Central Dogma
DNARNAProtein

16. RNA RNA Ribonucleic acid Always single stranded
Has ribose as sugar instead of deoxyribose
Always single stranded
Uracil (U) instead of Thymine (T)
C=G
A=U
Three types of RNA
mRNA – messenger RNA
tRNA – transfer RNA
rRNA – ribosomal RNA

17. DNA vs RNA--Quiz yourself: DNA, RNA, or Both?
Single stranded
Double stranded
Uracil
Can leave nucleus
Replication
Coded instructions
Nitrogen base, sugar, and phosphate group
Transcription
Translation
Smaller

18. Transcription Transcription – the process of making mRNA from DNA
A.K.A. RNA synthesis
Takes place in the nucleus of cells
Enzymes, splicing (introns and exons)
mRNA leaves nucleus

19. Practice DNA = TAC - CCG - TAA - CTA - GCT - TTA

20. Transcription Practice
DNA = TAC - CCG - TAA - CTA - GCT - TTA
RNA = AUG - GGC - AUU - GAU - CGA - AAU

21. Codons Every 3 bases of mRNA codes for a specific amino acid
Amino acids are bonded together to make proteins

22. RNA= UCG 

23. RNA= UCG  Serine

24. GUG
CCC

25. RNA  PROTEINS
Translation - The act of making proteins from the nucleic acid code found in mRNA; location: ribosomes
tRNA – transfer RNA – translates the 3 letter codons into proteins
tRNA has an anti-codon – a 3 letter sequence complementary to the mRNA codons
Each anti-codon corresponds to a certain amino acid

27. Amino acids bond together and protein is released.

28. Translation

29. Cell organelles involved in protein synthesis and processing
Nucleus—genetic code
Ribosome—protein factory
Endoplasmic Reticulum—transport system (“shipping and receiving”)
Golgi Apparatus—modify, package, & transport (“post office” or “Amazon warehouse”)
Proteins can be packaged in vesicles and shipped out or used within the cell
Mnemonic: N R E G V

30. Practice: Transcribe and Translate!
DNA: TGG CGA GGA RNA: Amino Acids:

32. Practice: Transcribe and Translate!
DNA: TGG CGA GGA RNA: ACC GCU CCU Amino Acids: Threonine-Alanine-Proline

33. Check your vocabulary:
hydrogen bond mutation nucleotide nucleus phenotype phosphate group polypeptides proteins ribonucleic acids - RNA ribosomes thymine transcription translation uracil
adenine amino acids chromosomes codon complimentary strand cytosine deoxyribonucleic acid DNA replication double helix endoplasmic reticulum enzymes genes golgi apparatus guanine

34. Mutations
Mutations can delete, substitute, invert, or insert one or more nitrogen bases to a gene.
Parts or entire chromosomes can be copied, deleted, or altered.
Effects can be positive, negative, or neutral.
Mutations in gametes may be inherited in offspring generations.
Mutations can be induced in biotechnology experiments—like oil-eating bacteria

35. Mutations Types Gene Missense—alters an amino acid
Nonsense—makes stop codon
Frameshift (Deletion, Insertion)—affects all subsequent amino acids

38. Nature vs Nurture
You are a product of both your genes and your environment.
Genes are segments of DNA that code for proteins: DNARNAProteins
Many environmental influences affect gene expression (ex.—height is determined by both genes and nutrition)
A phenotype is how a gene is expressed (ex.—height, brown hair, sickle cells)

39. Genetics
Complete a Punnett Square for the following: An alien homozygous recessive for green skin mates with another alien who is heterozygous for red skin. Follow simple dominance rules. Predict the % of offspring with green skin and then with red skin.

40. PUNNETT SQUARES Diagrams used for: Example: Flipping Coins
Predicting the result of a cross.
Determining the probability of a certain result.
PROBABILITY – the likelihood that something will happen (it is not definite)
Example: Flipping Coins
What is the probability of HEADS?
1/2
What is the probability of TAILS?
What is the probability of 2 HEADS in a row
1/2 x 1/2 = 1/4
Each flip is an independent event
Previous outcomes DON’T affect future outcomes

41. GENETICS – the study of heredity.
HEREDITY – the transmission of genes from parents to offspring.
GREGOR MENDEL – the father of genetics.

42. Vocabulary:
A. Small section of DNA coding for a protein B. Genetic makeup; ex. Tt C. Gene that is masked by another; represented by a lower case letter; ex. t D. Gene that covers up or masks another gene; represented by a capital letter; ex T E. Two identical forms of a gene: ex TT or tt F. Two different forms of a gene: Tt G. Physical appearance of expression of a gene; ex. Brown eyes H. Different forms of a gene; ex red or white flowers
Phenotype
Genotype
Heterozygous
Homozygous
Dominant
Recessive
Gene
Allele

44. MENDEL’S CONCLUSIONS from pea plant experiments:
Traits are controlled by genes
GENE – small segment of DNA on a chromosome that codes for a trait.

45. 2. Genes have alternative forms.
ALLELE – alternative forms of a gene
Every individual has 2 alleles for each trait
One from mom
One from dad
Example:
Purple flowers = P (from mom)
White flowers = p (from dad)
Genotype of offspring = Pp

46. 3. Alleles can be dominant or recessive
Dominant alleles are always expressed
Recessive alleles can be masked by Dominant ones.
Recessive alleles are expressed only when there are two copies
EXAMPLES:
T- tall TT - tall
t – short Tt – tall
tt – short

47. 4. An individual is said to be Homozygous if both of its alleles are the same.
TT or tt
DD or dd
An individual is said to be Heterozygous if its alleles are different.
Aa Tt
Bb Dd

48. 6. LAW OF SEGREGATION - alleles are separated during the formation of gametes. A gamete can only have ONE allele or THE OTHER
T = Tall
t = short
If a plant has Tt, gametes can either have a T or t in them
If a plant has TT, gametes can only have T in them
If a plant is tt, gametes can only have a t in them
**Remember—letters represent forms of a gene!

50. LAW OF INDEPENDENT ASSORTMENT - alleles for different characteristics are distributed to gametes independently.
EXAMPLE: Just because you have one dominant trait (Ex: Brown eyes), does not mean that you have ALL dominant traits.

52. Incomplete Dominance and Co-Dominance

53. Incomplete Dominance Neither allele is dominant over the other.
Heterozygous individuals have a phenotype that is in between the homozygous individuals
Understand the inheritance pattern—symbols may differ (caps, lower case, ‘) and be able to read keys.

54. Snapdragons
In snapdragons, flower color can be red, pink, or white. The heterozygous condition results in pink flowers WW RW RR

56. Incomplete Dominance Cross
Key:
R= Red
r= White
F1 Phenotype:
100% pink
F1 Genotype:
100% heterozygous Rr

57. F1 Cross Key: R= Red r= White Phenotype: 1:2:1 25% Red 25% White
50% Pink
Genotype: 1:2:1
25% homozygous RR
25% homozygous rr
50% heterozygous Rr

58. Co-dominance Both alleles are expressed equally
Neither allele is recessive
Both expressed as if they are a mixed dominance--patterns
Erminette chickens
Roan Cows/Horses

59. Co-Dominance Erminette Chicken
Key:
B =Black
B1 = White B B B1 B B1 B B1 B1 B B1 B B1
P generation
Black chicken X White chicken
F1 generation = erminette (checkered patterned)
Phenotype: 4:0 or
100% erminette
Genotype: 4:0 or
100% heterozygous

62. Multiple Alleles So far every trait has had only 2 variations
Some characters have more than two  ex. Blood types
Individuals still have only 2 alleles
Examples: Coat color in rabbits

63. Multiple Alleles
C= full color  Dominant to all other alleles cch = Chinchilla  recessive to C dominant to c ch = Himalayan  recessive to both C and cch. Dominant to c allele c= albino, no color  recessive to all other alleles. Inherit C  cch  ch  c Dominant Recessive (Continuum of dominance)

64. in

65. What’s your type?
Multiple Alleles AND Codominance

67. Blood Type Percentages
Data from CDC 2002

68. in

69. Blood Type Inheritance (Understand PATTERN, read keys.)

70. Incomplete and Codominance

71. Incomplete Dominance
When one trait does not completely take over the other trait.
Based on the above definition what do you think would happen when a homozygous black cat (BB) crosses with a homozygous white cat (WW)?
BB x WW

72. BB x WW (Incomplete Dominance)BW
BB- black
WW- white
BW- grey
4/4 grey kittens

73. Codominance
When one trait is neither dominant or recessive, therefore both are expressed.
Based on the above definition what do you think would happen when a homozygous black cat (BB) would cross with a homozygous white cat (WW)?

74. BB x WW (Codominance) B W BW BB- black 4/4 striped WW- white
BW- black and white striped
4/4 striped

75. Karyotypes
Charts or pictures that show chromosomes; help to determine chromosomal disorders and gender
Can see extra or missing chromosomes (whole or part)

78. Pedigree
Charts that show how traits are inherited through generations; can help determine mode of inheritance
Circles=female Squares=male
Read KEY! Different colors/shading show people expressing trait
(Sometimes half of a colored/shaded symbol show carriers)

82. has 47 total chromosomes in his body cells
1. Turner’s Syndrome A Male who has an extra X chromosome; he
has 47 total chromosomes in his body cells
2. Klinefelter’s Syndrome B Female who is missing an X
chromosome—only has one copy (45 total
chromosomes in body cells)
3. Down Syndrome/Trisomy 21 C Dominant gene mutation; usually begins
in midlife; brain damage begins and person
loses control over his/her body; 50% chance
of giving this disease/gene to offspring
4. Hemophilia D Bleeding disease; more males than
females (sex-linked); lack of clotting factor
in blood—lots of external and internal
bleeding when blood vessels broken
5. Sickle cell anemia E Extra copy of the 21st chromosome; short
stature, slanted eyes, lower intelligence
6. Color blindness F Cannot see all colors; sex-linked
inheritance pattern or head trauma
7. Huntington’s Disease G Red blood cells are not shaped properly;
can cause tiredness from not carrying
enough oxygen; displays codominance
8. PKU H. Lack enzyme to break down a certain amino
acid; can cause severe mental retardation

83. Vocabulary
recessive sex-linked test cross biotechnology cloning DNA fingerprinting DNA sequencing electrophoresis gene therapy genetic engineering genetically modified
organisms recombinant DNA selective breeding stem cell transgenic organism
alleles chromosomes codominance dominant DNA genes genetics genotype heterozygous/hybrid homozygous/pure incomplete dominance multiple alleles pedigree phenotype polygenic Punnett square