What is monohybrid and dihybrid cross?
Mono accounts for one gene
Dihybrid for two
What is Recombinant frequency ø
It is the likelikehood of two alleles being separated during crossing over.
Genetic maps can be made using recombination frequnecy as the scale in centimorgans.
The hardy-Weinberg principle states that if a population...
meets certain criterila, then the allele frequencies will remain contant.
hardy-Weinberg 5 principles
- Large Population
- No mutations
- No sexual selection
- No migration in or out
- All genes equally successful at reproduced.
What are the measures of central tendency?
Measures of central tendency provide a single value representation for the middle of a group data
Most affected by outliers; all sum divided by total
Median: "Middle number"
Mode: comes up most
What are the 4 types of distributions?
Normal distribution, mean median and mode are all the same in the normal distribution
Standard distribution is a normal distribution with a mean of zero and a standard deviation of one, used for most calculations, 68% of the data points occus whitin one standard deviation of the mean, 95%withinn two and 99 with in 3.
Skewed distribution: Have differences in their mean, median and mode, the skew direction is the direction of the tail of the distribution
Bimodla distribution: Have multiple peaks, although not necessarily multiple modes, strictly speaking. It may be useful to perform data analysis on the two groups separately.
What are the 4 measures of Distribution?
Range,difference between largest and smallest value.
Interquartiles range: Difference between 3rd and 1st quartile.
Standard deviation: a measure of variability about the mean
Outliers: may be a result of true population variability, measurement errors or a non-normal distribution.
What is the probability/explanation of,
Mutually exclusive outcomes
The probability of an independent event does not affect the probability of another event happening, VS dependent (yes)
Mutually exclusive outcomes cannot occur simultaneously
When a set of outcomes is ehxaustive there are no other possible choices.
What us a hypothesis test use?
use a known distribution to determine whether a hypothesis of no difference (null) can be rejected.
What do we use to determine statistical significance?
Using the comparison of a p-value to the selected significance level alpha, usually 0.05.
f your P-value is less than the chosen significance level then you reject the null hypothesis i.e. accept that your sample gives reasonable evidence to support the alternative hypothesis. It does NOT imply a "meaningful" or "important" difference; that is for you to decide when considering the real-world relevance of your result.
Type 1 error and Type 2 error
Type I; incorrectly rejecting the null hypothesis
Type II Incorrectly fail to reject the null hypothesis
Used to estimate population mean, a wider interval is associated with higher confidence level.
Correlation and causation
Correlation and Causation are separate concepts that are linked to hills criteria
A correlation between variables, however, does not automatically mean that the change in one variable is the cause of the change in the values of the other variable. Causation indicates that one event is the result of the occurrence of the other event; i.e. there is a causal relationship between the two events.
How must we apply data, two points here.
Data must be interpreted in the context of the current hypothesis and existing scientific knowledge.
Statistical and practical significace are distinct.