Chapter 9: Genetics, Patterns of Inheritance

Question 1

Genetics

Answer 1

Scientific study of heredity.

Question 2

Heredity

Answer 2

Transmission of traits from one generation to the next.

Question 3

Hybrids

Answer 3

Offspring of two true-breeding varieties.

Offspring resulting from combining the qualities of two organisms of two different varieites or species.

Question 4

Character

Answer 4

Heritable features that vary among individuals.

Question 5

Trait

Answer 5

Variant of character

Specific characteristic of an individual

Question 6

Homozygous Trait

Answer 6

the same trait from both parents
For example: AA or aa

Question 7

Heterozygous

Answer 7

Different traits from each parent
For example: Aa

Question 8

Alleles

Answer 8

Two different versions of genes for each trait.

Question 9

Homozygous Alleles

Answer 9

Alleles are identical

Question 10

Heterozygous Alleles

Answer 10

Alleles are different

Question 11

Dominant Allele.

Answer 11

The allele that determines the appearance of the organism.

Question 12

Recessive Allele

Answer 12

The other allele, which has no noticeable effect on the appearance.

Question 13

How many alleles does a gamete carry?

Answer 13

One allele from each inherited character.

Question 14

Punnett Square

Answer 14

Highlights the four possible combinations of gametes and offspring that result from each cross.

Question 15

Phenotype

Answer 15

An organism’s physical trait (what you can see)

Question 16

Genotype

Answer 16

An organism’s genetic makeup (what you cannot see)

Question 17

Monohybrid Crosses

Answer 17

A cross between two individuals that differ in only one character.

Examples: flowers 3 are purple and one is white.

Question 18

Dihybrid Cross

Answer 18

The crossing of parental varieties differs in TWO characters

Example: the peas, color and round/wrinkled

Question 19

Testcross

Answer 19

An individual of the dominant phenotype (but with an unknown genotype)

Question 20

What is the Law of Independent Assortment ?

Answer 20

The inheritance of one character does not affect the inheritance of another.

Question 21

What is the Law of Segregation

Answer 21

The two alleles for characteristics segregate (separate) from each other during the production of gametes retaining their individuality.

Question 22

What is the Law of Dominance?

Answer 22

Alleles will act in a way that dominant alleles will mask recessive alleles.

Question 23

Incomplete Dominance

Answer 23

F1 hybrids have an appearance in between the phenotypes of the two parents.

Question 24

Codominance

Answer 24

When the effect of the two alleles is equally visible in the phenotype of the heterozygote.
They are being equally expressed.

Question 25

Pleiotropy

Answer 25

One mutant gene affects several different characteristics.

Question 26

Polygenic Inheritance

Answer 26

Additive effects of two or more genes on a single phenotype.
These traits are controlled by multiple genes and/or influenced by the environment.

suchas height or skin pigmentation

Question 27

Epistasis

Answer 27

One gene alters the expression of another gene

Question 28

Linked Genes

Answer 28

Are located closed together on a chromosomes
they may be inherited together

Question 29

Epigenetic Inheritance

Answer 29

The transmission of traits by mechanisms not directly involving DNA sequence.
DNA and protein components of chromosomes can be chemically modified.

Question 30

What are some environmental factors that play a role in epigenetic inheritance?

Answer 30

Temperature
Solar Light
Drugs and chemicals
diet
oxygen levels.

Question 31

Family pedigree

Answer 31

Shows the HISTORY of a trait in a family.

Question 32

Wild-Type Traits

Answer 32

Those seen most often in nature

Question 33

Carriers of Disorders

Answer 33

Individuals who have the recessive allele but appear normal.

Question 34

Who determines the sex of the offspring?

Answer 34

Males with the XY chromosome

Question 35

Sex Linked Genes

Answer 35

Only genes that are located on a set of chromosomes. Specifically chromosome #23