Priciples of Heredity : Mendels Laws, Heredity, and Probability

What scientific approach did Mendel use to discover the principles of heredity?

Mendel used carefully planned experiments breeding garden peas.

What are true-breeding plants?

Plants that produce offspring of the same variety when they self-pollinate.

What is a monohybrid cross?

A cross between two plants differing in one trait.

What is a dihybrid cross?

A cross between two plants differing in two traits.

What is the P generation in Mendel's experiments?

The true-breeding parents.

What is the F1 generation?

The hybrid offspring of the P generation.

What is the F2 generation?

The offspring produced when F1 individuals self-pollinate or cross-pollinate.

What is Mendel's law of segregation?

Each somatic cell has two alleles, but each sex cell has only one allele.

What are the possible genotypes for flower color in Mendel's pea plants?

PP (purple), Pp (purple), pp (white).

What is the expected phenotypic ratio from a monohybrid cross?

3:1 ratio.

What does the multiplication rule of probability state?

For independent events, the probability of both occurring is the product of their individual probabilities.

What does the sum rule of probability state?

For outcomes that cannot occur at the same time, the probability of either occurring is the sum of their individual probabilities.

In the context of cystic fibrosis, what is the inheritance pattern?

Cystic fibrosis is inherited as an autosomal recessive trait.

What is the probability that two heterozygous parents (Cc) will have a child with cystic fibrosis?

25% or 1/4.

How can you determine the genotypes of parents in a genetic cross?

By analyzing the phenotypes of the offspring and using Punnett squares.

What is a branch diagram used for in genetics?

To visualize the possible gametes and offspring ratios in dihybrid crosses.

What is the significance of the 16 box Punnett square?

It is used to determine the genotypic and phenotypic ratios in dihybrid crosses.

What is the allele key for pea shape and color?

Y = Yellow, y = Green, R = Round, r = Wrinkled.

What are the possible gametes from a dihybrid cross of RRYY and rryy?

RY and ry.

What is the expected phenotypic ratio for a dihybrid cross?

9:3:3:1 ratio.

What is the purpose of a testcross?

To determine the genotype of an individual with a dominant phenotype.

What is the expected outcome when crossing a true-breeding purple, wrinkled plant with a true-breeding green smooth plant?

All F1 offspring will be purple and smooth.

What is the probability of having two affected children consecutively in a recessive trait?

1/4 x 1/4 = 1/16.

What does it mean if traits are said to assort independently?

The inheritance of alleles for one gene does not affect the inheritance of alleles for another gene.

What are the dominant and recessive traits in pea plants for height and flower color?

Tall is dominant over short; purple is dominant over white.

What is the significance of the 3:1 ratio in Mendel's monohybrid crosses?

It indicates the dominance of one trait over another in the offspring.

What is the expected genotypic ratio from a monohybrid cross?

1:2:1 ratio (homozygous dominant: heterozygous: homozygous recessive).

What is the role of Punnett squares in genetics?

To predict the genotypes and phenotypes of offspring from genetic crosses.