Chapter 2: Mendelian Inheritance and Probability

Question 1

pangenesis

Answer 1

Hippocrates suggestion that “seeds” are produced by all parts of the body, which are then collected and transmitted to the offspring at the time of conception, causing certain traits of the offspring to resemble those of the parents. (400BCE)

Question 2

What is Hippocrates concept of inheritance called?

Answer 2

pangenesis

Question 3

blending inheritance

Answer 3

the view that the factors that dictate hereditary traits can blend together from generation to generation. Refuted by Mendel.

Question 4

Who performed the first systematic study of genetic crosses?

Answer 4

Kölreuter, in experiments with tobacco from 1761 to 1766, concluded that both parents make equal genetic contributions to their offspring, consistent with blending inheritance: the factors that dictate hereditary traits can blend together from generation to generation. Refuted by Mendel.

Question 5

What did Kölreuter conclude from his experiments?

Answer 5

Kölreuter, in experiments with tobacco from 1761 to 1766, concluded that both parents make equal genetic contributions to their offspring, consistent with blending inheritance: the factors that dictate hereditary traits can blend together from generation to generation. Refuted by Mendel.

Question 6

Gregor Johann Mendel

Answer 6

1822-1884: Austrian monk botanist who performed crosses on peas in 1856, considered the father of genetics

Question 7

hybridisation experiment

Answer 7

two distinct individuals with different characteristics are mated (crossed), to each other, the offspring are referred to as hybrids.

Question 8

cross

Answer 8

mating two distinct individuals with different characteristics

Question 9

hybrids

Answer 9

the offspring of a cross (a mating between two distinct individuals with different characteristics)

Question 10

self-fertilisation

Answer 10

pollen and egg are derived from the same plant

Question 11

cross-fertilisation

Answer 11

pollen and egg are derived from two different plants

Question 12

character

Answer 12

one of the general characteristics of an organism, traits (or variants) describe specific properties of a character

Question 13

trait

Answer 13

traits (or variants) describe specific properties of a character (one of the general characteristics of an organism)

Question 14

variant

Answer 14

variants (or traits) describe specific properties of a character (one of the general characteristics of an organism)

Question 15

strain

Answer 15

a strain (or true-breeding line) produces a trait (or traits) that do not vary in appearance from generation to generation, it is homozygous for that trait

Question 16

true-breeding line

Answer 16

a true-breeding line (or strain) produces a trait (or traits) that do not vary in appearance from generation to generation, it is homozygous for that trait

Question 17

monohybrid cross

Answer 17

A monohybrid cross is a mating between individuals who have different alleles at one genetic locus of interest. The character(s) being studied in a monohybrid cross are governed by two alleles for a single locus.
To carry out such a cross, each parent is chosen to be homozygous or true breeding for a given trait (locus). When a cross satisfies the conditions for a monohybrid cross, it is usually detected by a characteristic distribution of second-generation (F2) offspring that is sometimes called the monohybrid ratio.

Question 18

single-factor cross

Answer 18

A monohybrid cross (or single factor cross) is a mating between individuals who have different alleles at one genetic locus of interest. The character(s) being studied in a monohybrid cross are governed by two alleles for a single locus.
To carry out such a cross, each parent is chosen to be homozygous or true breeding for a given trait (locus). When a cross satisfies the conditions for a monohybrid cross, it is usually detected by a characteristic distribution of second-generation (F2) offspring that is sometimes called the monohybrid ratio.

Question 19

empirical approach

Answer 19

Empirical research is a way of gaining knowledge by means of direct and indirect observation or experience. Empirical evidence (the record of one’s direct observations or experiences) can be analyzed quantitatively or qualitatively. Through quantifying the evidence or making sense of it in qualitative form, a researcher can answer empirical questions, which should be clearly defined and answerable with the evidence collected (usually called data).

Question 20

P generation

Answer 20

The parental generation, the initial generation that is crossed

Question 21

F1 generation

Answer 21

The first filial generation, the initial offspring of a cross

Question 22

F2 generation

Answer 22

The second filial generation, the offspring of the F1 generation

Question 23

Particulate theory of inheritance

Answer 23

The genes that govern traits are inherited as discrete units that remain unchanged as they are passed from parent offspring, Mendell called them factors, we now call them genes

Question 24

Gene

Answer 24

A unit of heredity that may influence the outcome of an organism’s traits

Question 25

Allele

Answer 25

Different versions of the same gene

Question 26

Mendel’s law of segregation

Answer 26

Two copies of a gene segregate (or separate) from each other during transmission from parent to offspring

Question 27

Homozygous

Answer 27

An individual possessing two copies (alleles) of a gene

Question 28

Genotype

Answer 28

The genetic composition of an individual

Question 29

Phenotype

Answer 29

The observable characteristics of an organism

Question 30

Heterozygous

Answer 30

An individual caring to different copies of alleles

Question 31

Dihybrid cross

Answer 31

A cross which studies two different characteristics in the same group of individuals

Question 32

Nonparental

Answer 32

Individuals of the F2 generation with combinations of traits that were not found in a true-breeding P generation

Question 33

Mendel’s law of independent assortment

Answer 33

Two different genes will randomly assort their alleles during the formation of haploid cells

Question 34

Genetic recombination

Answer 34

With an offspring receives a combination of alleles different from those in the parental generation

Question 35

What mechanisms are responsible for genetic recombination?

Answer 35

Independent assortment, crossing over

Question 36

Dihybrid testcross

Answer 36

Dihybrid individuals are mated to individuals that are homozygous recessive for the two characters. Independent assortment predicts a 1:1:1:1 ratio

Question 37

Loss-of-function alleles

Answer 37

An allele which encodes a defective copy of the gene product, often (but not always) inherited in a recessive manner

Question 38

Pedigree analysis

Answer 38

Using family trees to determine the type of inheritance pattern that the gene follows, used when controlling gamete combinations is not possible (aka humans??)