Question

9 10 11 12

9. John who has type O blood) has a son with type A blood. Which of the following female could be this child's mother? Explain your ves/no answer for each female. Martha (type 0) Sue (type A) Jenny (type B) Debbie (type AB) 10. Darlene and Walter (who both have type B blood) have a son with type o blood. How is this possible? What are the genotypes for Darlene and Walter? Walter Darlene Explanation for son's bloodtype: 11. How does polygenic inheritance determine human skin coloration? What other factors are involved in human skin coloration? 12. Bill has normal color vision, and he marries Ann who also has normal color vision but whose father had red-green color blindness (a sex-linked trait). What is the probability that they will have a colorblind child? Determine the genotypes of the parents and draw a Punnett square, (remember you must show X and Y chromosomes for sex-linked traits) genotype of Bill_ genotype of Ann

Answer 1

BLOOD GROUP INHERITANCE - ALLELES - IA IP, 10 IATA, IATO – A BLOOD GROUP IB B B - B BLOOD GROUP IA IB - AB BLOOD GROUP Iº I - 'o' BLOOD GROUP QUESTION-9- JOHN - 'O' Bloon GROUP (I° 1°) SO - 'A' BLOOD GROUP (II°) → SON GOT JA ALLELE FROM MOTHER AND from FATHER (JOHN) SO, MOTHER SHOULD BE WITH ALLELE, OPTIONS- (a) MARTHA- 'o' BLOOD GROUP – NO BECAUSE SHE DOES NOT HAS 'I' ALLELE, (5) SUE CA' BLOOD GROUP – 'YES' - I^ 1° | IAIA & IA ALLELE FROM I ALLELE from MOTHER FATHER GROUP ( SON - 70 - "A' BLOOD JENNY - B BROOD GROUP - Wor - IB IB ) Iº I° → NOTA ALL DEBBLE – TYPE AB' - . ' BONO TALLELE TYPE 'AR A TA ALLELE XI FROM (D) DEBBLE - TAIB – FATHER SON - IAIO - A BLOOD GROUP,

QUESTION 10 DAR LENE, WALTER - B' BLOOD GROUP (IB IB OR BI°) SON - 'o' BLOOD GROUP (Iº I°) THIS IS ONLY POSSIBLE WHEN BOTH PARENTS HAVE I ALLELE IN THEIR GENOTYPE so GENOTYPES OF PARENTS- DARLENE - IPI WALTER - IBI 4 LAINATION IBIO X IB to GAMETES- 15Iº DB 1 10 IB IB IB 10 H1H IBI° 12° IP GENOTYPE OF SON - 10 BLOOD GROUP

Question 11.
Polygenic inheritance/ Quantitative inheritance :-
• When single characteristic is controlled by more than two genes.
For human skin colour -
• Human skin colour is determined by the amount of pigment - melanin.
• At least four or more genes are involved in melanin production.
For each gene one allele (dominant) codes for melanin production amd the other allele (recessive) does not.
• The combination of melanin producing alleles determines the degree of pigmentation and this leads to continuous variation of skin colour.
Other factors -
• Environmental factors played a huge role in skin color determination. High sun exposure and more UV rays led to dark skin color and low sun exposure and low UV rays led to lightly skin.

QUESTION 12 → COLOUR-BLINDNESS - - LINKED RECESSIVE INHERITANCE. MALE - + NORMAL X xºy - COLOUR-BLIND, FEMALE- XX NORMAL Xex - NECTOR (NORMAL x x - COLOUR BLIND. X PHENOTYPE

BILL NORMAL COLOUR VISION ANN NORMAL COLOUR VISION . [xx D xx] FATHER IS COLOUR BLIND Cxey) IS INHERITE) from FATHER TO ANN, so GENOTYPE OF ANN- (xx) CROSS- BILL ANN (XY) (xx) Ganetes - GANETES- x,y J x, x gel xx xay RESULTS 6 50% CHILD - NORMAL ( XX AND XY) 25%. CHILD - VECTOR I NORMAL Cxex) 25% - COLOURBLIND -Xey So. PROBABILITY OF COLOURBLINO CHILD IS – 25% OR /