INHERITANCE AND PROBABILITY PENNY LAB PLEASE HELP ME

Question

In genetics, when we are trying to figure out how traits may be passed from parents to offspring, probability is an important consideration. If we know a little bit about the trait we are studying, we can use probability to predict how the gene in question will be transferred from parents to offspring.

 As an example, let’s toss a coin: If you examine a coin, you’ll see that it has 2 sides—heads and tails—and so there are 2 possible outcomes when the coin is tossed: it will land with the “heads” side up, or with the “tails” side up. 

When you toss the coin, the probability of getting a “heads” is ½, or 50%. This represents the number of desired outcomes (heads = 1) divided by the number of possible outcomes (heads + tails = 2). 

There is also a probability of ½ that we will get a “tails” if we toss the coin.

 If we toss our coin only two times, we might get 2 “heads”, 2 “tails”, or 1 “heads” and 1 “tails.” But the more times we toss our coin, the more likely we are to get closer and closer to our expected probability of 50% “heads” and 50% “tails.” Based upon what we know about coins, we form an hypothesis that the probability of getting a “heads” when we toss the coin is ½ or 50%. Then we test our hypothesis by tossing the coin and recording the results.

 

MY HYPOTHESIS (Expected Results) IF I toss a coin 100 times, THEN I expect to get _______HEADS and _______TAILS.

 PROCEDURE: 

1. Use 2 pennies. One penny represents an inherited pair of genes in a parent. The other penny represents the same pair of genes on the other parent. H= heads=> dominant gene (P =purple) t = tails => recessive gene (p= white) 

2. Both parents have one dominant allele and one recessive allele for their genotype HT (Pp - heterozygous) Pp x Pp

3. Today each coin is a “parent”. Toss your coins at the same time and then record your results under “Tally” on your data table.

 4. Continue until you have tossed your coins 100 times.

 5. Complete the rest of your data table.

 DATA TABLE:

Genotype	Tally	Total		%	Phenotype (purple/or white)
HH (PP)			/100
Ht (Pp)			/100
tt  (pp)			/100

Answer 1

When you flip a coin 100 times you expect to get 50 heads and 50 tails.

Express each genotype using an "and/or" statement. According to the laws of probability, substitute "and" with "times" and "or" with "plus".

HH (PP). Heads and Heads. 1/2 x 1/2 = 1/4 = 25%. Purple. Total will be approx 25.

Ht (Pp). (Heads and Tails) or (Tails and Heads). (1/2 x 1/2) + (1/2 x 1/2) = 1/4 + 1/4 = 2/4 = 1/2 = 50%. Purple. Total will be approx 50.

tt (pp). Tails and Tails. 1/2 x 1/2 = 1/4 = 25%. White. Total will be approx 25.

Note the genotypic ratio is 1 PP : 2 Pp : 1 pp.

Note the phenotypic ratio is 3 purple : 1 white.