Unit 9-Patterns of Inheritance

Question 1

Mendelian Genetics

Answer 1

made the DNA model
hypothesis
experimental design 
found true breeding lines 
used large amounts of DNA
statistical analysis

Question 2

define heredity

Answer 2

the transmission of traits from one generation to the next

Question 3

define genetics

Answer 3

the scientific study of heredity

began by Mendel

Question 4

what is a character

Answer 4

a heritable feature that varies among individuals such as flower colour

Question 5

what is a trait

Answer 5

each variant for a character such as purple OR white flowers

different forms of a gene

Question 6

what is a phenotype

Answer 6

the distinguish between an organisms physical traits (what you can see)
outward expression of the characteristic

Question 7

what is a genotype

Answer 7

its genetic makeup, what it has but may not show

the alleles present

Question 8

what is a gene

Answer 8

DNA encoding for a product or characteristic

Question 9

what is an allele

Answer 9

the alternative versions of a gene
form of a gene
has two copies one from each parent
some are dominant and some are recessive

Question 10

what Is a dominant allele mean

Answer 10

that is what is expressed
it masks the expression of another allele
does not mean the normal or common trait

Question 11

what is a recessive allele mean

Answer 11

has no noticeable effect on the organisms appearance

Question 12

what is homozygous dominant

Answer 12

when the offspring receives two identical alleles for a gene that are dominant BB

Question 13

what is homozygous recessive

Answer 13

when the offspring receives two identical alleles for a gene that are recessive bb

Question 14

what is a heterozygous

Answer 14

an organism that has two different alleles for a gene

carriers for the recessive trait

Question 15

what is self fertilization

Answer 15

sperm carrying pollen grains released from the stamens and land on the egg containing carpel

Question 16

what is cross fertilization

Answer 16

fertilization of one plant by pollen from a different plant

Question 17

what is true breeding

Answer 17

varieties for which self fertilization produced offspring all identical to the parent

Question 18

what is a hybrid

Answer 18

the offspring of two different varieties

Question 19

what are the multiple generations of mendels studies

Answer 19

the P generation 
- parental 
- true breeding plants 
the F1 generation 
- the parental hybrid offspring 
the F2 generation 
- when the F1 plants are self fertilized each other and their offspring is the F2gen

Question 20

what is a monohybrid cross

Answer 20

a cross involving one trait

between the true breeding P generation

Question 21

what is a dihybrid cross

what is a trihybrid cross

Answer 21

a cross involving two traits
true breeding between the P generation
a tri means three traits

Question 22

Mendel’s experiment

Answer 22

P generation (Purple x White)
gives 
F1 generation (All purple) 
gives 
F2 generation (white color comes back 3:1)

Question 23

what are punnet squares

Answer 23

a diagram that shows the four possible combinations of alleles that could occur when these gametes combine

Question 24

define law of segregation

Answer 24

a sperm or egg carries only one allele for each inherited character because allele pairs separate (segregate) from each other during the production of gametes
separate in meiosis

Question 25

define the law of independent assortment

Answer 25

each pair of alleles segregates (assorts) independently of other pairs of alleles during gamete formation the inheritance of one character has no effect on the inheritance of another

Question 26

what is a test cross

Answer 26

used to determine the genotype of the unknown parent

Question 27

what are wild type traits

Answer 27

those prevailing in nature and are not necessarily specified by dominant alleles

Question 28

what are some dominant character traits that are inherited in humans

Answer 28

windows peak cleft chin hitchhikers thumb

Question 29

what are some recessive disorders inherited in humans

Answer 29

sickle cell anemia | cystic fibrosis

Question 30

what are some dominant disorders inherited in humans

Answer 30

achondroplasia | huntingtons disease

Question 31

what is sickle cell anemia

Answer 31

no dominant allele (codominance) | no intermediate phenotype has both

Question 32

what is incomplete dominance

Answer 32

does not support the blending hypothesis the appearance of F1 hybrids falls between the phenotypes of the two parental varieties NO DOMINANT ALLELE ie) human hair texture or snapdragon flowers

Question 33

what is complete dominance

Answer 33

the dominant allele has the same phenotypic effect whether present in one or two copies

Question 34

multiple alleles

Answer 34

more then two allelic forms of a given gene (diploid)

Question 35

what is an example of multiple alleles

Answer 35

human ABO blood types | both IA and IB are dominant

Question 36

define codominance

Answer 36

the blood example IA and IB are co-dominant both alleles are expressed in heterozygous individuals who have type AB blood neither allele masks the presence of the other different then incomplete dominance

Question 37

define polygenic inheritance

Answer 37

the additive effects of two or more genes on a single phenotypic character multiple genes affect a single trait

Question 38

what are some examples of polygenetic traits

Answer 38

human skin pigmentation | has three melanin genes

Question 39

define the chromosome theory of inheritance

Answer 39

that genes occupy specific loci (positions) on chromosomes and it is the chromosomes that undergo segregation and independent assortment during meiosis

Question 40

what do the chromosomes affect in inheritance

Answer 40

law of segregation law of independent assortment linked genes sex linked genes

Question 41

what are lethal dominant genes

Answer 41

most genetic disorders are homozygous recessive ie) achondroplasia

Question 42

what is achondroplasia

Answer 42

partial lethal dominant condition heterozygous survive homozygous dominant die the mutation affects long bones of the heterozygous that survive

Question 43

is it possible to have a complete dominant condition what is an example

Answer 43

very rare because the homozygous typically die | ie) huntingtons disease

Question 44

explain huntingtons disease

Answer 44

causes neuron degeneration abnormal movements and mental deterioration symptoms appear at 35-45

Question 45

define linked genes

Answer 45

genes located close together on the same chromosome tend to be inherited together

Question 46

does linked genes follow Mendel's law of independent assortment

Answer 46

NO

Question 47

explain crossing over

Answer 47

the recombination of DNA | occurs during prophase 1 when the homologous pair up to form tetrads and cross over at the chiasma

Question 48

do linked genes always assort together

Answer 48

yes without crossing over

Question 49

what happens to the linked genes after crossing over

Answer 49

it is random and it recombinants | the closer the genes the further they will move apart ?

Question 50

what is the linkage map

Answer 50

a diagram used to notice the relative gene locations

Question 51

what are the different types of sex chromosomes to determine sex

Answer 51

``` humans or fruit flies - XX OR XY birds - ZZ OR ZW grasshoppers - XX OR X0 bees and wasps - 2N OR 1N ```

Question 52

sex linked inheritance

Answer 52

occurs on the X chromosome unique inheritance pattern male pattern baldness colour blindness

Question 53

Allele frequencies p and q

Answer 53

p = the Dominant frequency q = the recessive frequency p + q = 1

Question 54

What are the four conditions of studying populations that are not evolving

Answer 54

1) mutations - change allele frequencies 2) mating must be random neither phenotype has an advantage 3) small populations are prone to random changes so there must be a large population 4) isolated population - no one leaves and no one enters