Paterns Of Inheritance - Mendel’s Peas

Question 1

Heredity

Answer 1

The transmission of traits from one generation to the next

Question 2

Genetics

Answer 2

The scientific study of heredity

Question 3

Pangenesis (the Particulate hypothesis)

Answer 3

Proposed by Hippocrates, an early explanation for inheritance. Suggested that particles called pan-genes came from all parts of the organism to be incorporated into eggs or sperm

Question 4

The blending hypothesis

Answer 4

The idea that genetic material from two parents blends together. Does not explain how traits that disappear in one generation can reappear in later ones

Question 5

Gregor Mendel

Answer 5

The father of genetics

Question 6

What did Mendel do in 1866?

Answer 6

Deduced the principals of genetics by breeding garden peas, relied upon a background of mathematics, physics and chemistry, correctly argued that parents pass on to their offspring’s discrete heritable factors, and stressed that the heritable factors (genes) retain their individuality generation after generation

Question 7

Characters

Answer 7

Varieties with distinct heritable features

Question 8

Traits

Answer 8

Character variants

Question 9

True breeding

Answer 9

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

Question 10

Hybrids

Answer 10

The offspring of two different varieties

Question 11

Genetic cross

Answer 11

Cross-fertilization (also called hybridization)

Question 12

P generation

Answer 12

True breeding parental generation

Question 13

F1 generation

Answer 13

Hybrid offsprings

Question 14

F2 generation

Answer 14

A cross between F1 generation organisms

Question 15

Monohybrid cross

Answer 15

A cross between two individuals differing in a single character

Question 16

Did the all purple F1 generation prove or reject Mendel’s blended hypothesis?

Answer 16

Reject

Question 17

Alleles

Answer 17

Alternative versions of genes that account for variations in inherited characters

Question 18

Homozygous

Answer 18

Two of the same allele are inherited

Question 19

Heterozygous

Answer 19

Two different alleles are inherited

Question 20

Phenotype

Answer 20

The organisms appearance

Question 21

Dominant allele

Answer 21

If the two alleles of an inherited pair differ, this one determines the organisms phenotype

Question 22

Recessive allele

Answer 22

If the two alleles of an inherited pair differ, this one has no noticeable effect in the organisms appearance

Question 23

Mendel’s Law of Segregation

Answer 23

The two alleles for a heritable character separate (segregate) during gamete formation and end up in different gametes

Question 24

Locus

Answer 24

The specific location of a gene along a chromosome

Question 25

Punnets square

Answer 25

Used to show possible combinations of sperms and eggs

Question 26

Genotype

Answer 26

The organisms genetic makeup

Question 27

Dihybrid cross

Answer 27

Produced when crossing two true breeding parents differing in two characteristics

Question 28

Mendel’s Law of Independent Assortment

Answer 28

The inheritance of one character has no effect in the inheritance of another, each pair of alleles segregate independently from the other

Question 29

The multiplication rule

Answer 29

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

Question 30

The addition rule

Answer 30

The probability that any one of two or more mutually exclusive events will occur in calculated by adding together their individual probabilities

Question 31

Complete dominance

Answer 31

Organisms in the F1 generation always looking like one of the two parental varieties

Question 32

Incomplete dominance

Answer 32

Organisms in the F1 generation having appearances that fall between the phenotypes of the two parental varieties

Question 33

Co-dominance

Answer 33

Each allele is expressed in separate distinguishable ways

Question 34

Pleiotropy

Answer 34

Occurs when a single gene affects many phenotypic characters, eg. sickle cell disease in humans

Question 35

Polygenetic inheritance

Answer 35

A single character may be influenced by many genes, yields quantitative characters eg. skin color and height

Question 36

Epistasis

Answer 36

Expression of a gene at one locus alters the phenotypic expression of a gene at a second locus

Question 37

Recessive inheritance

Answer 37

Two recessive alleles are needed to show disease, Heterozygous parents are carriers of the disease-causing alleles
Examples of recessive disorders: cystic fibrosis, sickle cell disease, phenylketonuria (PKU) and Tay-Sachs disease

Question 38

Dominant inheritance

Answer 38

One dominant allele is needed to show disease, dominant lethal alleles are usually eliminated from the population

Examples of dominant disorders - achondroplasia, Huntington’s disease, hypercholesterolemia

Question 39

Albinism

Answer 39

A lack of pigmentation, a recessive trait, heterozygotes are carriers, only observed in offspring if both parents are carriers