Chapter 9 - Mendel's Experience and Inheritance

Question 1

Genetics

Answer 1

Study of genes and their transmission from 1 generation to the next.

Question 2

Inheritance

Answer 2

the passing down of genetic traits from generation to generation

Question 3

Gene

Answer 3

unit of DNA that encodes for a protein
-portion of DNA that determines traits
-responsible for the expression of traits
-no pair
-eye color, hair color

Question 4

Allele

Answer 4

a specific form of gene
-responsible for the variations
-pairs (always 2/gene)
-blue eyes, straight hair

Question 5

Genome

Answer 5

sum total of all of an individuals DNA

Question 6

Gene Locus

Answer 6

the location of a specific gene or pair of genes on the chromosomes
-pair of genes: always one copy is maternal and one is paternal

Question 7

Homozygous

Answer 7

when 2 alleles of same gene are identical

Question 8

Heterozygous

Answer 8

when 2 alleles of same gene are different

Question 9

Genotype

Answer 9

the set of all alleles

Question 10

Phenotype

Answer 10

physical characteristics

Question 11

ALL alleles of same gene encode the same type of ____.

Answer 11

Protein

Question 12

Dominant Alleles

Answer 12

alleles that mask the expression of others

Question 13

Recessive Alleles

Answer 13

alleles that are masked by dominant alleles

Question 14

Punnet Squares

Answer 14

predict what genotypes the offspring of 2 individuals will have

Question 15

Dihybrid Crosses

Answer 15

genes of different chromosomes segregate independently of one another during gamete formation

Question 16

Polygenic Traits

Answer 16

phenotypes determined by more than one gene
-skin color, eye color, foot size, height

Question 17

Height Genes

Answer 17

each height gene has a “short” allele and a “tall” allele
-tall alleles are dominant
-ratio of tall to short dictates height

Question 18

Polygenic - Eye Color

Answer 18

eye color depends on multiple genes
-each allele represents a specific color
-final eye color is the ratio of all dominant color alleles to homozygous recessive color alleles

Question 19

Mutations

Answer 19

changes in the nucleotide bases (nitrogen base pair) of our DNA that are different from the original DNA sequence
-some do not alter the protein sequence and are harmless, called silent mutations
-other mutations can slightly change the proteins but do not cause disease or otherwise harm the organism in which they are expressed; contribute to various alleles for normal phenotypes
-mutations that can cause disease or otherwise harm the organisms are called deleterious

Question 20

Types of changes to the nucleotides in the DNA sequence can include:

Answer 20

-deletions
-substitutions
-insertions

Question 21

Deleterious Mutations

Answer 21

result in non-functional or dysfunctional protein products
- central dogma: DNA dictates protein creation
-normal (non-mutated) allele is called the wild-type allele
-mutant alleles either dominant or recessive compared to the wild-type allele

Question 22

Phenylketonuria (PKU)

Answer 22

Homozygous Recessive Disorder
-requires both alleles to have a deleterious mutation
-wild-type allele is dominant, mutant allele is recessive
-single gene disorder = only takes mutation in one gene to cause disease
-heterozygous persons = “carriers” of PKU but are not affected themselves.
-phe = essential AA, requires PHA enzyme to break down (phenylamine hydroxylase) to turn into tyr which is another essential AA
-when a person can’t make PHA enzyme, decrease in tyr (which can be found in food), but also increases phe (causes behavioral issues, mental issues, disease)