Chapter 14 & 15

Question 1

Define alleles

Answer 1

different versions of genes

Question 2

define genes

Answer 2

genetic information that codes for a specific trait

Question 3

define traits

Answer 3

a specific characteristic of an individual

Question 4

Define true breeding

Answer 4

homozygous dominant → AA
homozygous recessive → Aa

Question 5

Define heterozygous

Answer 5

Aa

Question 6

Define phenotype

Answer 6

physical expression of a gene

Question 7

Define genotype

Answer 7

the genetic makeup→ the combination of inherited allele

Question 8

What are the four parts of Mendel’s Model

Answer 8

1.Alternate versions of genes → ALLELES
2.Organisms inherit two copies of a gene
3.Dominant Allele and Recessive Allele
4.Law of Segregation

Question 9

Define Law of segregation

Answer 9

Two alleles will separate into two gamete cells

Question 10

Define Law of Independent assortment

Answer 10

2 alleles will independently separate into two gamete cells

Question 11

Define F2

Answer 11

cross between two individual from F1 generation

Question 12

define a testcross

Answer 12

breeding of a unknown genotype with recessive homozygous
To find the genotype of a dominant phenotype

Question 13

What are the steps to read a pedigree?

Answer 13

1. Determine if the trait is dominant or recessive:
   Dominant: will not skip a generation; one parent MUST have the trait
   Recessive: neither parent is required to have the trait- heterozygous
   2.Determine if the trait is autosomal or sex-lined
   X-linked recessive= males are much more commonly affected than females
   Autosomal traits: both males and females are equally likely to be affected

Question 14

During what phases of meiosis will the law of segregation take place?

Answer 14

In Anaphase 1: the homologous chromosomes will separate into two gamete cells
In Anaphase 2: the sister chromatids will separate into two gamete cells

Question 15

During what phases of meiosis does the law of independent assortment take place?

Answer 15

Anaphase 1- homologous chromosomes
Anaphase 2 sister chromatids
During metaphase 1 & 2 , alleles will independently orient on the metaphase plate

Question 16

What is a wild type?

Answer 16

phenotype most commonly observed
w+

Question 17

What is a mutant?

Answer 17

phenotype due to alleles that have changes
w

Question 18

What are some sex-linked diseases?

Answer 18

Colorblindness, hemophilia, and duchenne’s muscular dystrophy

Question 19

What is nondisjunction?

Answer 19

Homologous chromosomes do not move apart during during meiosis 1 & sister chromatids do not separate during meiosis 2;
can also affect autosomal chromosomes

Question 20

What are some autosomal nondisjunction disorders?

Answer 20

trisomy 21(down syndrome)
Trisomy 18
Trisomy 13

Question 21

In which chromosomes do autosomal nondisjunction disorders take place?

Answer 21

autosomes- 22 pairs

Question 22

What do people with sex chromosome nondisjunction have trouble with?

Answer 22

childbearing

Question 23

What are some sex chromosome nondisjunction disorders?

Answer 23

Kleinfelters, Turners

Question 24

What is kleinfelters disorder?

Answer 24

XXY → male
Sterile; Some female body characteristics

Question 25

Turners’ disorder

Answer 25

sterile; females; missing and X
X0

Question 26

XYY characteristics

Answer 26

extra aggression→ Male; taller than average and normal sexual development

Question 27

XXX characteristics

Answer 27

female- tall and slender; issues with personality & socialism: a difficulty with childbearing

Question 28

What is the difference between mitochondria DNA inheritance and Nuclear DNA inheritance?

Answer 28

mitochondrial and chloroplast DNA inherited from the mother
Nuclear DNA can be inherited from mother and father

Question 29

What is phenotypic plasticity?

Answer 29

effect of environment on phenotype

Question 30

Phenotypic plasticity in hydrangea flowers and pH

Answer 30

Flower color→ soil pH
Acidic soil- low pH→ blue or lavender
Basic soil→ higher pH→ pink or red flowers

Question 31

Phenotypic Plasticity- Carbon dioxide levels and stomate density

Answer 31

Low amounts of CO2→ more stomates
High amounts of CO2→ fewer stomates

Question 32

Phenotypic Plasticity- of Siamese cats

Answer 32

tyrosinase= catalyzes first step of melanin production
Temperature above 33C- inactive- no pigment
Temperature below 33C- active- pigment present

Question 33

Phenotypic plasticity- snow shoe hare

Answer 33

Ice pack- too cold; enzyme for white coat is not activated

Question 34

Phenotypic Plasticity- butterflying wings

Answer 34

Warm temperatures of wet season= large and bright eyespots
Cool temperatures in dry season= dull an dsmall eyespots

Question 35

what are linked genes

Answer 35

genes that are very close together. Due to their closeness, they cannot cross over and crossing over results in recombination. Thus, not many recominants were formed.
exception to medelian genetics

Question 36

define parentals

Answer 36

offspring with the same genotype as the parents

Question 37

define recombinants

Answer 37

offspring that are a mix of their parents

Question 38

recombination frequency of 50% or greater

Answer 38

genes are either are on different chromosomes or are very far apart from each other on the same chromosome such that they will assort independently

Question 39

recombination frequency less than 50%

Answer 39

genes are closer together and linked

Question 40

when would you reject null hypothesis?

Answer 40

when chi square value is greater

Question 41

incomplete dominance

Answer 41

when two alleles express their traits in a blended manner

Question 42

co-dominance

Answer 42

mixture of two dominant alleles