genes

Question 1

where are genes contained

Answer 1

chromosomes

Question 2

who discovered genes

Answer 2

Gregor mendel

Question 3

what did Gregor Mendel study?

Answer 3

pea plants

Question 4

overview of gregor mendels experiment

Answer 4

Record parent traits; prevent plant from self-fertilizing; fertilized from another plant; collected seeds; record traits of offspring

Question 5

medel crossed bred….

Answer 5

true breeding varieties

Question 6

Mendel’s pea generations:

Answer 6

P generation: cross true breeding parents called hybridization
F1 generation: first offspring
F2: offspring of offspring

Question 7

what happens to genetic material during fertilization?

Answer 7

material from both parents combine during fertilization

Question 8

what is a gene?

Answer 8

instructions about something (about a trait) does not say what instructions are, just what they are about.

Question 9

alleles

Answer 9

different versions of a gene; what instructions actually say

Question 10

dominant alleles

Answer 10

(capitalized): trait can be seen with only 1 copy of the allele

Question 11

recessive alleles

Answer 11

(lower cased): trait can only be seen if a dominant allele is NOT present

Question 12

law of segregation

Answer 12

alleles separate when gametes are formed

Question 13

homozygote

Answer 13

2 copies of same allele

Question 14

heterozygote

Answer 14

2 different alleles

Question 15

genotype:

Answer 15

genetic composition of an individual

Question 16

phenotype:

Answer 16

physical characteristics of an individual

Question 17

monohybrid cross: P generation

Answer 17

homozygous dominant or recessive (YY or yy)

Question 18

monohybrid cross: F1 generation
Genotype? Phenotype?

Answer 18

Genotype: 4 heterozygous (Yy)
Phenotype: 4 dominant (color of Y trait)

Question 19

monohybrid cross: F2 generation
Genotype? Phenotype?

Answer 19

-Genotype:
*1 homozygous dominant
*2 heterozygous
*1 homozygous recessive
-Phenotype:
*3 dominant
*1 recessive

Question 20

test cross reveals…

Answer 20

genotype that created that phenotype

Question 21

dihybrid cross looks at…

Answer 21

2 characteristics at once

Question 22

dihybrid cross: P generation

Answer 22

*Dominant genotype for both traits
*Recessive genotype for both traits

Question 23

dihybrid cross: F1 generation

Answer 23

heterozygous for both traits

Question 24

dihybrid cross: F2 generation

Answer 24

9:3:3:1 phenotype ratio

Question 25

multiple alleles

Answer 25

genes can have 2+ alleles (Can still follow dominant/recessive pattern (can have more than 1 recessive pattern)

Question 26

incomplete dominance

Answer 26

one allele is not completely dominant *Heterozygotes have intermediate traits *Both alleles partially expressed

Question 27

codominance

Answer 27

neither allele is dominant or recessive Both alleles are expressed in heterozygotes

Question 28

pleiotropy:

Answer 28

genes often affect more than one trait

Question 29

example of pleiotropy

Answer 29

friendly foxes bread to be friendly also became cuter (on accident): had more juvenile characteristics such as larger eyes, bigger ears, and a “cuter” look.

Question 30

epistasis

Answer 30

phenotype of one gene can block phenotype of different gene *One gene is needed to see another gene: one recessive allele in one gene will influence a different gene

Question 31

polygenic inheritance

Answer 31

 Broad range of phenotypes * Trait more complex than present or absent * True of most genes  Many small differences controlled by multiple genes  Average phenotype is most common  Extremes are uncommon

Question 32

pedigrees show

Answer 32

family connections

Question 33

genetic disorders are caused by

Answer 33

allele not functioning properly

Question 34

cystic fibrosis

Answer 34

mucus clumps in lungs caused by a mutant Cl- ion transport protein

Question 35

cystic fibrosis is recessive:

Answer 35

fine if you have 1 functioning pump, not fine if 2 mutant alleles make no functional proteins

Question 36

Huntington's disease creates

Answer 36

protein clumps that kill brain cells

Question 37

Huntington's disease is dominant:

Answer 37

presence of normal allele does not prevent the clumps

Question 38

genetic screening during pregnancy

Answer 38

-Amniocentesis: remove amniotic fluid and grow fetal cells -Chorionic villus sampling: remove tissue from fetal portion of placenta

Question 39

chromosome ___ determines gender

Answer 39

23

Question 40

female chromosome

Answer 40

XX

Question 41

male chromosome

Answer 41

XY

Question 42

sex linked genes:

Answer 42

-gender determining chromosome may lack genes -One gender has only 1 copy of some genes *Males in humans *More likely to display recessive trait -No matching dominant trait -Recessive trait can appear in other gender if parent with small chromosome has trait

Question 43

most x linked disorders are dominant/recessive?

Answer 43

recessive

Question 44

x linked traits are more common in

Answer 44

males: most genes are missing from Y chromosome

Question 45

color blindness occurs in many men since

Answer 45

instruction for cone pigments are on X chromosome

Question 46

x inactivation

Answer 46

 Level of trait can be affected by number of instructions

Question 47

independent assortment

Answer 47

genes are inherited separately IF genes are on different chromosomes

Question 48

if genes are on the sam chromosome,

Answer 48

alleles tend to inherit together (genes are LINKED)

Question 49

crossing over

Answer 49

homologous pair swap a section during prophase 1 of meiosis

Question 50

some chromosome alterations can include

Answer 50

deletion, duplication, inversion, and translocation

Question 51

deletion:

Answer 51

part of chromosome is lost oGenes may be removed from lost chromosome

Question 52

duplication:

Answer 52

selection of chromosome is duplicated oDuplicated section combined with rest of chromosome

Question 53

inversion:

Answer 53

piece breaks and is reattached backward oGenes are in different order than before

Question 54

translocation

Answer 54

piece of one chromosome is attached to non-homologous chromosome oNon homologous chromosomes may swap pieces

Question 55

nonmendelian inheritance: genomic imprinting

Answer 55

: only receive an active copy of gene from one parent

Question 56

____ and ___ have DNA and genes

Answer 56

mitochondria and chloroplasts

Question 57

all organelle genes are inherited from

Answer 57

mother