Chapter 9 - Patterns of Inheritance

Question 1

Character

Answer 1

A heritable feature that varies among individuals

Ex. flower colour

Question 2

Trait

Answer 2

A variant of a character,

Ex. purple or white flowers

Question 3

Carpel

Answer 3

The female part of the plants that contains the stigma style and ovary. (The stigma is the sticky part on top of the carpet that traps the pollen.)

Question 4

Stamen

Answer 4

The pollen producing male part of the flower that consists of a filament (stalk) and an anther (top where the pollen is)

Note: pollen contains the sperm of the plant

Question 5

Self fertilization

Answer 5

When the pollen of the plant fertilizes the egg of the same plant. Makes for true breeding meaning that the new plant is identical to the parent plant

Question 6

Cross fertilization

Answer 6

Fertilization of one plant with the pollen of another plant.

Question 7

Hybrid

Answer 7

The offspring of two different varieties

Question 8

Genetic cross / hybridization

Answer 8

The crossing of two different varieties

Question 9

P generation

Answer 9

True breeding parental plants

Question 10

F1 generation

Answer 10

The first filial generation

These are the hybrid offspring from crossing two different, true breeding varieties.

Question 11

F2 generation

Answer 11

The second filial generation.

The result of crossing two F1 hybrids together.

Question 12

Allele

Answer 12

An alternate version of a gene that resides at the same locus on homologous chromosomes

Question 13

Monohybrid cross

Answer 13

Crossing 2 true-bred plants that differ in only one character (WW)

Ex. White flower and purple flower

Question 14

Mendels 4 hypotheses

Answer 14

1. There are alternate versions of genes.
2. For each character, an organism inherits 2 alleles that could either be homo/heterozygous.
3. If the 2 alleles differ, one will be dominant and one recessive.
4. A sperm or egg carries only 1 allele (law of segregation)

Question 15

Dihybrid cross

Answer 15

Crossing two true-breeding plants that differ in two characters (RRYy)

Question 16

Genotype

Answer 16

An organisms genetic makeup

Expressed as (for example) BB, Bb, or bb

Question 17

Phenotype

Answer 17

An organisms physical traits that you can actually see being expressed. (Dependant on the genotype)

Question 18

Epistasis

Answer 18

An interaction between the products of two genes, in which one of these genes modifies the phenotypic expression produced by the other.

Question 19

Incomplete dominance

Answer 19

Where a trait of the F1 offspring appears as a blending of the parents traits.

Ex. One red flower and one white flower producing a pink flower

Question 20

Pleiotropy

Answer 20

When a single gene affects many phenotypic characters

Ex. Melanin pigment gene, sickle cell disease

Question 21

Polygenic inheritance

Answer 21

When two or more genes affect a single phenotypic character.

Ex. Skin colour which is controlled by 3 genes

Question 22

Epigenetics

Answer 22

Heritable changes, and gene expression that are not attributable to alterations in the genetic code of DNA.

i.e. your environment can cause changes that affect the way your genes work. Certain things you do will turn certain genes on or off and these on/off genes can be passed down to offspring.

Question 23

The chromosome theory of inheritance

Answer 23

States that genes occupy specific loci (locus) on chromosomes, and it is the chromosomes that undergo segregation and independent assortment during meiosis.

Question 24

The law of segregation

Answer 24

Allele pairs separate from eachother during the production of gametes. They split during anaphase I of meiosis

Question 25

Linked genes

Answer 25

Genes located close together on the chromosome (tend to be inherited together)

Question 26

Sex-linked gene

Answer 26

A gene on a sex chromosome that codes for something other than determination of sex.

Question 27

True breeding

Answer 27

A kind of breeding in which the parents would produce offspring that carry the same phenotypes as the parent.
Means the parent generation but be homozygous for each trait.

Question 28

The law of independent assortment

Answer 28

The separation of the alleles into gametes is random and independent.

This works if the alleles are on different chromosomes and are not linked.

Question 29

The rule of addition

Answer 29

The probability for all possible outcomes of an event to occur, must always add up to 1

Questions using this rule use OR

Ex. Change of guessing a number between 1-10 is 1/10, chance of not guessing it right is 9/10 = 10/10 (1)

Question 30

The rule of multiplication

Answer 30

The outcomes of each event are independent of each other.

Question using this rule use AND

Ex. Probably of coin 1 landing on heads (= 0.5), and the second coin landing on heads (= 0.5)
0.5 x 0.5 = 0.25 or 25%