Ch. 3B Probability, Statistics, and Pedigrees (Exam 2) Flashcards
Simple Probability & Predicting Genetic Outcomes, Matching Predictions to Observed Outcomes, Tracking & Revealing Patterns of Inheritance in Humans
What is probability?
The likelihood of an event occurring
What is the range of probability?
0-1
What does a probability of 0 mean?
No chance
What does a probability of 1 mean?
100% chance
What is the most basic example of probability in genetics?
Mendelian ratios
What is the main idea behind independent events?
The outcome of Event 1 has no effect on the outcome of Event 2 and so on
What is an example of an independent event?
A coin toss b/c one toss will not affect the outcome of other tosses
Which math law corresponds to independent events?
Product law
What is another name for the product law?
Multiplication rule
What is the main idea behind mutually exclusive events?
They do not occur at the same time
What keywords can help identify a mutually exclusive event?
Either/or
Which math law corresponds to mutually exclusive events?
Sum law
What is another name for the sum law?
Addition rule
What is the main idea behind conditional probability?
The probability of a particular outcome depends on another outcome or given condition
What is the formula for conditional probability?
Pc = Pa / Pb
What does each variable for conditional probability stand for?
Pc = conditional probability Pa = probability of an event/interest Pb = probability of a given conditional event
What keyword may help possibly identify conditional probability scenarios?
Given
What does binomial theorem calculate?
The outcome of repeated trials with only 2 outcomes
When solving binomial distribution the long way, what are the 2 main steps involved?
Step 1) Product law
Step 2) Sum law
What does the product law step of binomial distribution detail?
Calculating the product of independent events to get an initial probability
What does the sum law step of binomial distribution detail?
Finding the # of possible combinations and adding the initial probability from the previous step based on the # of combinations i.e. 3 combinations = adding the initial probability to itself 3 times
What popular algebraic concept can be used to solve binomial distribution? List this formula too.
Pascal’s triangle - (a +b)^n = 1
What is the main binomial distribution formula that will most likely be used on the exam?
((n!) / (s! * t!)) * ((a^s) * (b^t))
What does the binomial distribution variable “n” stand for?
n = # of trials/repeats
What does the binomial distribution variable “s” stand for?
s = # of 1st outcome
What does the binomial distribution variable “t” stand for?
t = # of 2nd outcome
What does the binomial distribution variable “a” stand for?
a = probability of 1st outcome
What does the binomial distribution variable “b” stand for?
b = probability of 2nd outcome
When is a deviation in data more likely to occur?
When there is a small sample size
What is the general definition of the null hypothesis?
The assumption that there is no difference or deviation
What 2 assumptions does the null hypothesis make about differences in measured & predicted values?
1) Data/ratios that agree with our expectations show no difference between measured & predicted values
2) Any differences between measured & predicted values can be attributed to chance
What is the overall goal of the null hypothesis?
To reject or accept the null hypothesis
What does it mean to reject the null hypothesis?
Differences found are not due to chance, so you should re-examine your data/assumptions
What does it mean to accept the null hypothesis?
Differences found between observed & expected outcomes are due to chance
What does a chi-square analysis determine about your observed data?
Determines how well measured/observed data fits the accepted data
How do the results of a chi-square analysis relate to the null hypothesis?
The chi-square analysis tells if your results reject or accept the null hypothesis
