10 Genetics - Potato & Onion People The ‘Vegetable People’ are an isolated population of people living on Vegetabilia; an island in the middle of ’Nowhere Sea’. They come in all shapes and sizes. Just like human, they have characteristics that are passed from parent to child. Part One : Background There are two sexes: females are onions and males are potatoes. There are five other characteristics that can differ between individual Vege People. Eye Colour Nose Type Arm Length Feet/Toes Hair colour Blue pin Big red drawing pin Long straw Toes Cream wool Green pin Small red pin Short Straw NO toes Red wool Below is a list of all the possible phenotypes and their corresponding genotype(s) for each trait Characteristic Phenotype Genotype(s) Responsible Allele GENDER Female onion XX X Male potato XY Y EYE BLUE pin BB or Bb B COLOUR GREEN pin bb b NOSE Big RED drawing pin RR or Rr R SIZE Small RED pin rr r ARM Long Straw LL or Ll L LENGTH Short Straw ll l FEET Toes TT or Tt T TYPE NO Toes tt t HAIR CURLY wool CC or Cc C STRAIGHT wool cc c

TASK 1: TASK 2: TABLE 2 : Ma & Pa TASK 3: (5 marks) Dominant Trait From the information in the previous table; list the dominant and recessive characteristics (5 marks) Dominant Trait Recessive TASK 2: (6 marks) Two Vegetable people, Ma Onion and Pa Potato, have an offspring. The offspring of vegetable people are know as Vegemite’s. There are a number of possible characteristics that a Vegemite may inherit from these parents. First you need to find out what these are Complete table 2 below for Ma Onion and Pa Potato filling in what the phenotype will be for each characteristic. TABLE 2 : Ma & Pa Characteristic Ma ONION Pa POTATO Genotype Phenotype Gender XX XY Eye colour Bb bb Nose Rr rr Arm Length Ll Feet Type Tt Hair colour Cc cc TASK 3: Use Punnet Squares to predict the ratios of the Vegemite’s for each of the traits. (12 marks) P a Ma X Y P a Ma P a Ma P a Ma P a Ma P a Ma Ratio of male/ female Vegemites. % Male _______ % Female _______ Ratio of blue/green EYES? % Blue Eyes ______ % Green Eyes _______ Ratio of big / small NOSES % BIG Nose _______ % Small Nose _______ Ratio of long/ short ARMS % Long Arms _______ % Short Arms _______ Ratio of toes/ NO TOES % Toes _______ %NO Toes _______ Ratio of curly/straight HAIR % CURLY hair _______ % Straight Hair _______

TABLE 3 : Vegemite Offspring PART 2 : Experiment The allele for each trait that Ma and Pa possess, have been placed in containers. In sexually reproducing organisms, new individuals arise a s a result of egg (female sex cell) and sperm (male sex cell) combining in a process called fertilisation. The egg and sperm only contain ONE allele for each trait. Which allele is present is a totally random process, in other words there is an equal likelihood that either allele is passed on, whether it is the same type or different. TASK 4: (6 marks) In table groups collect a set of containers with the alleles in them. Each container has 4 alleles for one characteristic for Ma (2xred) and Pa (2xblue) Select one ‘red’ and one ‘blue’ stick from the container. ie one allele from Ma and one allele from Pa This is the genotype of your Vegemite. Write this genotype in Table 3 and then determine the phenotype that will be shown Continue for all five traits in the table and the sex of your Vegemite. TABLE 3 : Vegemite Offspring Characteristic Genes Vegemite Offspring From MA From PA Genotype Phenotype Heterozygous/ Homozygous Gender Eye colour Nose Arm Length Feet Type Hair colour TASK 5: (3 marks) Have your table checked by your teacher before proceeding. Make your Vegemite offspring using the body parts provided according to your table. Give your Vegemite offspring a name and then draw a colour picture The picture is to be at least 8cm tall, this is your ‘baby photo’ so include lots of detail in your picture/diagram. Attach the picture to this work.

From Punnet Squares Task 3 (6 marks) In task 3, you used punnet squares to predict the frequency of each characteristic. EG : 50% chance of female (onion), 50% chance of male (potato) Record these values in Table 4 below in the Predicted Frequency column. The Gender is completed for you. You will need to collect class totals for each characteristic of the Vegemite offspring. Example: how many offspring were female (onion), how many were male (potato)? Record this information in Table 4 TABLE 4 : Vegemite Class Totals Characteristic Dominant Phenotype Predicted Frequency Recessive Phenotype Class TOTAL From Punnet Squares Task 3 Gender (potato) 50% (onion) Eye colour (blue) (green) Nose (big red pin) (small red pin) Arm Length Feet Type Hair colour Q1. How do the expected (predicted) ratios compare to the observed ratios obtained by the class? Described for each trait (i.e. were they higher or lower than expected?) ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ (2 marks)

Q 2 . Explain the term genotype and phenotype, homozygous and heterozygous, dominant and recessive. You might like to use Ma or Pa’s genetic information to support your explanation ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ ____________________________________________________________________________________________________________________________________________________________________________________ (6 marks) Q 3. Use the ratios you determined in Task 3 to help answer the following question. If Ma and Pa vegetable had 40 offspring how many Vegemites’ would have each characteristic? (6 marks) Characteristic Variation Number in family with this characteristic GENDER Female Male EYE BLUE pin COLOUR GREEN pin NOSE Big RED drawing pin SIZE Small RED pin Characteristic Variation Number in family with this characteristic ARM Long Straw LENGTH Short Straw FEET Toes TYPE NO Toes HAIR CURLY wool COLOUR STRAIGHT wool Q 4. A widow’s peak hairline dominates over the recessive straight hair line. A woman who is homozygous for widow’s peak has a child with a heterozygous father. What is the probability that the child will carry the recessive gene? Show all working. ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ ________________________________________________________________________________________________________________________ (3 marks)