Mendel chose to use true-breeding varieties of pea plants for his studies. What is a true-breeding variety?

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

What is hybridization?

When two different true-breeding varieties are crossed.

True-breeding parents are __ generation

P

Hybrid offspring of P generation are called __ generation

F 1

When F1 individuals self-pollinate or cross- pollinate with other F1 hybrids, __ generation is produced

F 2

What is a dominant trait?

A trait that will be overpowering in the phenotype.

What is a recessive trait?

A trait that can be easily overpowered in the phenotype unless no dominant trait is present.

An allele codes for different variations of a _______. Each resides at specific locus on a specific ____________.

gene, chromosome

For each characteristic an organism inherits (minimum) ____ alleles. One from each parent

2

Two alleles at a particular locus of the chromosome will code for the same characteristic although they may or may not code for the same trait. True or false?

True. For example, the two alleles may both code for flower colour. They may code for the same flower colour or two different ones.

In punnet squares a __________ ___________ represents a dominant allele, and a _________ _________ represents a recessive allele

capital letter, lowercase letter

An organism with two identical alleles for a character is _____________

homozygous

An organism that has two different alleles for a gene is _______________

heterozygous

Could you consider heterozygous plants true-breeding?

No

What is the difference between a phenotype and a genotype?

A phenotype is what you see and a genotype is what's in the genes

In the example of feather colour in chickens, BB and Bb chicken have the same ________ (black), but different____________

phenotype, genotypes

What is a testcross?

A breeding tactic used to determine a mystery genotype by cross-breeding the individual with a homozygous recessive individual

F1 indivuduals heterozygous for one character were called ________________ in Mendel's experiments

monohybrids

A cross between two heterozygotes is called a _____________ cross

monohybrid

Crossing two true-breeding parents differing in two characters produces __________ (heterozygous for both characters)

dihybrids

dihybrid cross be?

To determine if two characters are transmitted as a package or independently

What is the law of independent assortment?

The law of independent assortment states that each pair of alleles segregates independently during gamete formation

What situation might the law of independent assortment not hold true in?

When two genes are really close on the same chromosome

What is the multiplication rule?

The multiplication rule states that the probability that two or more independent events will occur together is the product of individual probabilities

What is the addition rule

The addition rule states that the probability that any one of two or more exclusive events will occur is calculated by adding together their individual probabilities

For example: ¼ + ¼ = ½

Applying multiplication and addition rules a dihybrid cross is equivalent to ______ or ______ independent monohybrid crosses occurring simultaneously

two or more

Basic principles of segregation and independent assortment apply even to more complex patterns of inheritance, true or false?

true

What is the difference between complete dominance, incomplete dominance and codominance?

• Complete dominance occurs when phenotypes of the heterozygote and dominant homozygote are identical
• In incomplete dominance, the heterozygotes express an intermediate phenotype relative to the parental phenotypes.
• In codominance, two dominant alleles affect the phenotype in separate, distinguishable ways

Dominant alleles are more prevalent in the population. Ture or false?

False, six fingers/toes is dominant but rare

The four phenotypes of the ABO blood group in humans are determined by _______ alleles

three: A AB B O are four combinations of the same three alleles

How many possible genotypes are there for a person with blood type O?

1

What is the heterozygous blood type genotype in humans?

AB

The trait that blood types code for is the ___________ on the outside of the blood cell

carbohydrates

Blood type AB has _____ different carbohydrates on the cells whereas blood type O has _______

two, zero

What is pleiotropy?

Pleiotropy is a property where genes have multiple phenotypic effects

In epistasis, a gene at one locus alters the ___________ _____________ of a gene at a second locus.

For example, in Labrador retrievers and many other mammals, coat colour depends on two genes

phenotypic expression

What are Quantitative characters?

those that vary in the population along a continuum

What is indicates polygenic inheritance?

an additive effect of two or more genes on a single phenotype like skin colour in humans

What is the norm of reaction?

the phenotypic range of a genotype influenced by environment

When genetic and environmental factors collectively influence phenotype of a character it is said to be __________

Multifactoral

What is a pedigree?

a family tree describing interrelationships of parents and children across generations

Why are pedigrees relevant to genetics?

Because Inheritance patterns of particular traits can be traced and described using pedigrees and they can be used to make predictions about future offspring

What is a carrier?

are heterozygous individuals who carry the recessive allele but are phenotypically normal

Mating between close relatives decreases the chances of two mating between two carriers of the same allele, true or false?

False

Amniocentesis and chorionic villus sampling (CVS) are both examples of what kind of test?

Prenatal fetal testing for genetic disorders