Mendels Laws And Principles Of Heredity

What is a character?

An observable feature of an organism (e.g., flower color)

What is a trait?

A specific form of a character (e.g., purple or white)

What is an allele?

A version of a gene

What does homozygous alleles mean?

Having two identical alleles (AA or aa)

What does heterozygous alleles mean?

Having two different alleles (Aa)

What is true breeding or pure breeding?

All the individuals offspring have the same trait, suggesting that the individual is homozygous for all the alleles that code for that character

What is a genotype?

The genetic makeup of an individual

What is a phenotype?

The observable traits of an individual

What is a dominant allele?

An allele that is expressed even when only one copy is present

What is a recessive allele?

An allele expressed only when two copies are present (aa)

What is an autosomal mutation?

A mutation on chromosomes 1–22

What is a sex-linked mutation?

A mutation on X or Y chromosomes

What is a locus?

The physical location of a gene on a chromosome

What is the parental (P) generation?

The initial mating individuals

What is the F1 generation?

The first generation of offspring from the parental generation

What is the F2 generation?

The offspring of the F1 generation

What is a wild-type allele?

The most common allele in a population (+)

What is a variant allele?

Any allele different from the wild-type

What is a Punnett square?

A diagram used to predict possible genotypes of offspring

What gametes are produced from AaBb?

AB, Ab, aB, ab

What is the Law of Segregation?

Two alleles separate during gamete formation, and each gamete gets one allele

What is the Law of Independent Assortment?

Alleles of different genes assort independently into gametes

What is the genotypic ratio of a monohybrid cross (Aa × Aa)?

1 AA, 2 Aa, 1 aa

What is the phenotypic ratio of a monohybrid cross?

3 dominant: 1 Recessive

What is the phenotypic ratio of a dihybrid cross?

9:3:3:1

What is a test cross?

Crossing an unknown genotype with a homozygous recessive (aa)

What result indicates AA in a test cross?

All offspring show the dominant phenotype

What result indicates Aa in a test cross?

A 1

What is the AND rule in probability?

Probability of a set of independent events occurring
- Multiply probabilities when events occur together

What is an example of the AND rule?

Landing heads 3 times in a row:

Probability of landing head is ½ - now trying to do that 3 times:

1/2 × 1/2 × 1/2 = 1/8

What is the OR rule in probability?

Add probabilities for mutually exclusive events

• Add probabilities when multiple outcomes are possible

What is an example of the OR rule?

Getting 3 children of the same sex.

having male is ½ - now 3 times in a row is ½ x ½ x ½ = 1/8

having female is ½ - now 3 times in a row is ½ x ½ x ½ = 1/8

• two exclusive mutual events so add them together

1/8 + 1/8 = 1/4

When do you use the AND rule?

When there is only one way to achieve an outcome

When do you use the OR rule?

When there are multiple ways to achieve an outcome

What is the binomial probability formula?

P = (n! / (s!t!)) p^s q^t

What does p represent in binomial probability?

Probability of one outcome

What does q represent in binomial probability?

Probability of the alternative outcome

What does n represent in binomial probability?

Total number of events

What is the genotypical ratio?”

1:2:1

What is the phenotypic ratio?

3:1

What are linked genes?

Genes located close together that are inherited together

What are independent genes?

Genes that assort independently

What is a chi-square test?

A statistical test used to compare observed vs expected results

What is the chi-square formula?

X² = Σ (O − E)² / E

What is the null hypothesis?

The assumption that differences between observed and expected are due to chance

When do you reject the null hypothesis?

When X² is greater than the critical value

When do you accept the null hypothesis?

When X² is less than or equal to the critical value

What are degrees of freedom?

Number of categories minus 1

What is the alpha level?

The probability threshold (commonly 0.05)

• ex is taking someone innocent to trial and they are found guilty.

What is the purpose of the chi-square test?

To determine if deviations from expected ratios are due to chance or not