HEREDITY is the transmission of genes from parent to offspring.

Mendelian Genetics

1. GUESS THE WORD! Guess the terms using the coded letters of the alphabet at the TOP. 1.7 5 14 5 19- 2. 9 14 8 5 18 9 20 1 14 3 5- 3. 22 1 18 9 1 20 9 15 14- 4. 1 12 12 5 12 5- 4 15 13 9 14 1 14 20- 20 18 1 9 20- 16 8 5 14 15 20 25 16 5- A-1 B-2 C-3 D-4 E-5 F-6 G-7 H-8 I-9 J-10 K-11 L-12 M-13 N-14 O-15 P-16 Q-17 R-18 S-19 T-20 U-21 V-22 W-23 X-24 Y-25 Z-26 GENES INHERITANCE VARIATION ALLELE DOMINANT TRAIT PHENOTYPE

2. HEREDITY Inheritance and Variation

3. HEREDITY -is the passing on of traits from parents to their offspring either through asexual reproduction or sexual reproduction, the offspring cells of organisms acquire the genetic information of their parents. The study of heredity in Biology is GENETICS. Colour of the eyes Shape of the face Hairline Hair (curly or straight) Height

4. PICTURE PERFECT! K to 10 Critical Content in Science 8

5. INHERITANCE -i s the process by which genetic information is passed on from parent to children. This is why members of the same family tend to have similar characteristics.

6. What I KNOw ! Answer the Pre Test in Quarter 1 Module 3. Write your answer in your notebook. 1 to 15.

7. Choose the letter of the best answer and write it on your answer sheet. 1. Who is considered as the Father of Genetics? a. Gregor Mendel b. Reginald Punnett c. Theodor Boveri d. Walter Sutton 2. What tables are used to predict the outcome of crosses of traits from parents? a. Genetics Grid b. Punnett Squares c. Offspring Squares d. Mendelian diagram 3. Which of the following is the location of genes in the chromosomes? a. Centromere b. Locus c. Nucleus d. Telomere

8. 4. Which branch of biology is concerned with the study of how traits are inherited from parents to offsprings ? a. Eugenics b. Physiology c. Genetics d. Polygenic 5. What is the genotype of a person’s trait if an organism has two identical alleles for that trait? a. heterozygous b. homogeneous c. homologous d. homozygous 6. Which refers to the variant forms of a gene representing a certain trait? a. allele b. chromatids c. locus d. polyploid

9. 7. Which of these represents a heterozygous dominant genotype? a. GG b. Gg c. gg d. G 8. Which of the following BEST explains a non- Mendelian law of inheritance? a. Shows both recessive traits of the parents. b. Shows both dominant traits of the parents. c. Shows recessive traits and hides dominant traits. d. Shows dominant traits and hides recessive traits. 9. Which of the following does NOT belong to a non- Mendelian law of inheritance? a. Codominance b. Multiple alleles c. Incomplete dominance d. Law of independent assortment

10. 10. Which of the following statement is NOT TRUE about genes? a. Genes contain a pair of alleles. b. Genes are found only in body cells. c. Genes are segment on DNA strand. d. Genes are located in chromosomes. 11. Which of the following is a non- Mendelian Law of inheritance wherein neither allele is dominant over the other? a. Codominance b. Multiple Alleles c. Genetic Linkage d. Incomplete Dominance 12. Which of the following is NOT an example of codominance pattern of inheritance? a. Roan cattle b. AB blood type c. Erminette chicken d. Pink four o’clock flower

11. 13. The human blood group system is governed by multiple alleles, the A, B, O wherein O is recessive and A and B are codominant . Which of the following is the possible blood type of the offspring if the father has type A blood and the mother has type O blood? I.AO II.OO III.AA IV.AB a. I only b. I and II only c. I, II and III only d. II, III and IV only 14. Which of the following conditions is NOT an x-linked trait? a. Hemophilia b. Red-Green colorblindness c. Congenital night blindness d. Hypertrichosis pinnae auris 15. Which of the following statements is TRUE about sex-linked traits? a. Only occurs in males. b. Shows in all sons of affected male. c. The carrier daughter is phenotypically normal. d. The y-linked genes are responsible for "male pattern baldness".

12. VARIATION Genetic variation is a term used to describe the variation in the DNA sequence in each of our genomes. Genetic variation is what make us all unique whether in terms of hair colour or even the shape of our faces. Genes- is the basic physical and functional unit of heredity. Genes are made up of DNA DNA-deoxyribonucleic acid, a self replicating material present in nearly all living organisms as the main constituents of the chromosome.

13. ALLELE Is one possible forms of a gene. Most genes have two alleles, a dominant allele and a recessive allele. If an organism is heterozygous for that trait or possesses one of each allele, then the dominant trait is expressed. Example: RR, Rr , rr , XX, XY Chromosome-a structure in a all living cells that consist of a single molecule of DNA bonded to various proteins and that carries the genes determining heredity

14. CHROMOSOME

15. Activity 1. frayer model graphic organizer DEFINITION CHARACTERISTICS EXAMPLES NINO MENDELIAN PATTERN OF INHERITANCE NON EXAMPLES

16. Mendel’s Law of Inheritance:  Mendel’s First Law (Law of Segregation) – A parent who has two alleles for a gene can only pass on one allele or the other to each offspring.  Mendel’s Second Law (Law of Independent Assortment) – Two or more traits are inherited separately from each other; they don’t always occur together.  Mendel’s Third Law (Law of Dominance) – One dominant allele will take charge over a recessive allele and “mask” it. The only way recessive alleles can be seen is if an individual possesses two copies of the recessive allele. Non- Mendelian Law of Inheritance:  Incomplete Dominance - occurs when neither of two alleles is fully dominant nor recessive towards each other. This means that the two possible traits are blended together.  Codominance - occurs when two heterozygous alleles are fully expressed. Neither allele can dominate, so they both show up, but they do not blend they just coexist with each other.  Multiple Alleles - i nvolves more than just the typical two alleles that usually code for a certain characteristic in a species.

17. Gregor Johann Mendel Austrian Monk, born in what is now Czech Republic in 1822 Son of peasant farmer, studied Theology and was ordained priest Order St. Augustine. Went to the university of Vienna, where he studied botany and learned the Scientific Method Worked with pure lines of peas for eight years Prior to Mendel, heredity was regarded as a "blending" process and the offspring were essentially a " dilution"of the different parental characteristics.

18. Mendel’s peas Mendel looked at seven traits or characteristics of pea plants:

19. In 1866 he published Experiments in Plant Hybridization , ( Versuche über Pflanzen-Hybriden ) in which he established his three Principles of Inheritance He tried to repeat his work in another plant, but didn’t work because the plant reproduced asexually! If… Work was largely ignored for 34 years, until 1900, when 3 independent botanists rediscovered Mendel’s work.

20. Mendel was the first biologist to use Mathematics – to explain his results quantitatively. Mendel predicted The concept of genes That genes occur in pairs That one gene of each pair Is present in the gametes

21. A dominant trait is one that is phenotypically expressed in heterozygotes. It is opposed to a recessive trait. -represented by big letters DOMINANT

22. - a gene/trait that can be masked by a dominant gene. In order to have a trait that is expressed by a recessive gene, such as blue eyes you must get the gene for blue eyes from both of your parents. RECESSIVE

23. Phenotype All the observable characteristics of an organism that result from the interaction of its genotype with the environment. Examples of observable characteristics include behaviour, biochemical properties, colour (RED, WHITE, PINK) shape (round) and size (TALL & short).

24. -i s a set of genes in our DNA which is responsible for a particular trait. Example: RR, RW, WW, GENOTYPE Monohybrid cross : a genetic cross involving a single pair of genes (one trait); parents differ by a single trait. P = Parental generation F 1 = First filial generation; offspring from a genetic cross. F 2 = Second filial generation of a genetic cross

25. PUNNETT SQUARE The method by which one can determine the possible genotypes and phenotypes when two parents are crossed. OFFSPRING’S GENOTYPIC RATIO: 50% Yy , 50% yy OFFSPRING’S PHENOTYPIC RATIO: 50% Yellow, 50% Green PARENT’S GENOTYPIC RATIO: Yy and yy PARENT’S PHENOTYPIC RATIO: yellow and green

26. Monohybrid cross Parents differ by a single trait. Crossing two pea plants that differ in stem size, one tall one short T = allele for Tall t = allele for dwarf TT = homozygous tall plant t t = homozygous dwarf plant T T  t t

27. Monohybrid cross for stem length: T T  t t (tall) (dwarf) P = parentals true breeding, homozygous plants: F 1 generation is heterozygous: T t (all tall plants)

28. Punnett square A useful tool to do genetic crosses For a monohybrid cross, you need a square divided by four…. Looks like a window pane… We use the Punnett square to predict the genotypes and phenotypes of the offspring.

29. Using a Punnett Square STEPS : 1. determine the genotypes of the parent organisms 2. write down your "cross" (mating) 3. draw a punnett -square Parent genotypes: TT and t t Cross T T  t t

30. Punnett square 4. "split" the letters of the genotype for each parent & put them "outside" the p-square 5. determine the possible genotypes of the offspring by filling in the p-square 6. summarize results (genotypes & phenotypes of offspring) T t T t T t T t T T t t Genotypes: 100% T t Phenotypes: 100% Tall plants T T  t t

31. Monohybrid cross: F 2 generation If you let the F1 generation self-fertilize, the next monohybrid cross would be: T t  T t (tall) (tall) T T T t T t t t T t T t Genotypes of Offspring: 25 % TT 50 % Tt 25% tt Phenotype of Offspring: 75% Tall 25% dwarf

32. Secret of the Punnett Square Key to the Punnett Square: Determine the gametes of each parent… How? By “splitting” the genotypes of each parent: If this is your cross T T  t t T T t t The gametes are:

33. Once you have the gametes… T T t t T t T t T t T t  T T t t

34. Shortcut for Punnett Square… You only need one box! T T t t  T t Genotypes: 100% T t Phenotypes: 100% Tall plants If either parent is HOMOZYGOUS T t

35. Understanding the shortcut… T t T t T t T t T t T T t t = Genotypes: 100% T t Phenotypes: 100% Tall plants T t

36. If you have another cross… A heterozygous with a homozygous T t t t  T t t T t t t Genotypes: 50% T t 50 % t t Phenotypes: 50% Tall plants 50% Dwarf plants You can still use the shortcut!

37. Non mendelian pattern of inheritance

38. INCOMPLETE DOMINANCE CODOMINANCE MULTIPLE ALLELES SEX-LINKED TRAITS SEX-LIMITED TRAITS SEX INFLUENCED TRAITS NON MENDELIAN PATTERN OF INHERITANCE

39. INCOMPLETE DOMINANCE -O ccurs when the phenotype of the offspring is somewhere in between the phenotypes of both parents

40. Parent’s Genotype: RR and WW Parent’s Phenotype: Red and White Offspring’s Genotype: 100% RW Offspring’s Phenotype: 100% Pink

41. Show a cross between two pink FLOWERS (RW AND rw ) USING A PUNNETT SQUARE. DETERMINE THE GENOTYPIC AND PHENOTYPIC RATIO OF THE OFFSPRINGS.

42. ACTIVITY 1:Phenotypes and Genotypes in Incomplete Dominance

43. Act. 2. What’s my genotype and phenotype? Objective: Solve Genetic Problems related to incomplete dominance Table 1. Phenotype and Genotype of Gumamela Flower. 2. Write the Genotype and Phenotype of the Offspring when PINK FLOWER is crossed to a WHITE FLOWER. 3.Write the Genotypic and Phenotypic Ratio of the Offspring. RATIO: Genotypic Ratio: Phenotypic Ratio: PHENOTYPE GENOTYPE RED RR WHITE WW PINK RW

44. CODOMINANCE -when the traits appear together in the phenotype of the offspring

45. ACTIVITY 2: MYSTERY BULL Have you seen a roan goat? A red goat (RR=all red hairs) is mated with a white goat (WW=all white hairs) will result to a roan (RW=red and with white hairs).

46. Sample problem: determine the genotypic and phenotypic ratio of the kids goat if a white goat is mated with a roan goat.

47. Activity 3. codominance Objective: Solve genetic problems related to codominance . Procedure: Determine the genotypes and phenotypes of the parents goats if the kids (baby goats) are two roan and two red fur goats. Write the genotype of each kid. Parent’s Genotype :_________________________ Parent’s Phenotype :________________________ OFFSPRING GENOTYPIC RATIO=________________ OFFSPRING PHENOTYPIC RATIO=_______________ . Phenotype: Red Genotype:_____ Phenotype: Red Genotype:_____ Phenotype: Roan Genotype:_____ Phenotype:Roan Genotype:_____

48. Activity 3. codominance Objective: Solve genetic problems related to codominance . Procedure: Determine the genotypes and phenotypes of the parents goats if the kids (baby goats) are two roan and two red fur goats. Write the genotype of each kid. Genotype RR and RW_ Phenotype : Red and Roan RATIO: GENOTYPIC RATIO=50 % RR and 50 % RW PHENOTYPIC RATIO= 50% Red and 50% Roan Phenotype: Red Genotype:_____ Phenotype: Red Genotype:__ Phenotype: Roan Genotype:_ RW Phenotype:Roan Genotype:_____ RR R R W R RR RW

49. In solving problems involving non- Mendelian inheritance makes us realize that there a re no absolutes in real life. Codominance is the result of two alleles sharing their territory, so no color is dominant they simply share traits, representing their color . In cows, red and white do not combine to make pink. Instead, roan is produced. Codominance is all about sharing space and being independent.

50. Multiple alleles

51. SEX CHROMOSOME and SEX DETERMINATION

52. How many chromosomes do humans have? 46 chromosomes How many pairs of chromosomes do each individual have? 23 pairs of chromosomes for both male and female What do you call the 22 pairs of chromosomes? Somatic Chromosome How about the 23 rd chromosome? SEX CHROMOSOME

53. Human MALES and the other male organisms, such as other mammals and fruit flies, have NON IDENTICAL SEX CHROMOSOMES (XY) Females have identical (XX) SEX CHROMOSOMES

54. How is sex determined and inherited?

55. ACTIVITY 5. ARE YOU A BOY OR A GIRL? Draw a Punnett square which shows the inheritance of the sex chromosomes. Represent the female sex chromosomes with XX And the male sex chromosomes with XY .

56. GUIDE QUESTIONS What will be the sex of a child produced when an egg is fertilized by a sperm that has Y chromosome? What type of sperm must fertilize an egg to result in a female child? Based on this Punnett Square, what percent of children would you expect to be male? Which sex chromosome (gamete) is present in both male and female? Infer which sex chromosomes determine a person’s sex? What are the other factors that may influence the expression of human sexuality?

57. GUIDE QUESTIONS What will be the sex of a child produced when an egg is fertilized by a sperm that has Y chromosome? male 2. What type of sperm must fertilize an egg to result in a female child? X sperm 3. Based on this Punnett Square, what percent of children would you expect to be male? 50% 4. Which sex chromosome (gamete) is present in both male and female? The x chromosome 5. Infer which sex chromosomes determine a person’s sex? The y chromosome

58. 6. What are the other factors that may influence the expression of human sexuality? Answer: Environmental factors and the social interactions after birth may contribute to a certain degree to the expression of human sexuality

59. GOOD JOB SCIENTISTS! Now that you are familiar with the sex chromosomes, always remember that they also carry genes which are factors of heredity!

60. Sex linked traits

61. Activity 6. x matters?

62. Sex limited traits

63. Sex influenced traits

64. QUIZ

65. QUIZ (1/4)