Unit 3- Genetics

Question 1

genotype

Answer 1

genetic make-up of an organism; ex. TT or Tt

Question 2

phenotype

Answer 2

appearance of an organism; ex. tall plant/ green eyes

Question 3

Punnett square

Answer 3

used to predict the probable offspring in a cross

Question 4

homozygous/purebred

Answer 4

having the same alleles for a trait; ex. TT or tt

Question 5

heterozygous/hybrid

Answer 5

having two different alleles for a trait; ex. Tt

Question 6

pedigree

Answer 6

chart that shows relationships within a family; allows you to see how a trait is inherited within a family

Question 7

Down syndrome

Answer 7

trisomy of chromosome number 21

Question 8

clone

Answer 8

genetically identical cells

Question 9

transgenic organism

Answer 9

organism that contains genes from another organism

Question 10

polyploidy

Answer 10

when organisms have an extra set of chromosomes

Question 11

sickle cell anemia

Answer 11

disorder that causes the red blood cells to have an abnormal hemoglobin causing an abnormal shape

Question 12

incomplete dominance

Answer 12

both alleles in the heterozygote are partially expressed/blended; ex. pink flower

Question 13

Drosophila

Answer 13

fruit fly; organism used for modern genetics research

Question 14

monohybrid cross

Answer 14

cross involving one trait

Question 15

dihybrid cross

Answer 15

cross involving two traits

Question 16

allele

Answer 16

alternate form of the same trait; ex. the gene for plant height has an allele for tallness and an allele for shortness

Question 17

codominance

Answer 17

both alleles in the heterozygote are fully expressed; roan cattle, erminette chickens

Question 18

multiple alleles

Answer 18

a series of three or more forms of a gene

Question 19

gene map

Answer 19

chart that shows the distance between genes

Question 20

Huntingtons Disease

Answer 20

disorder of the central nervous system caused by a dominant gene; symptoms occur in middle age; deterioration and loss of control of voluntary movements

Question 21

cystic fibrosis

Answer 21

disorder characterized by excess mucus in the lungs

Question 22

autosome

Answer 22

chromosome pairs 1-22; AKA body chromosomes

Question 23

karyotype

Answer 23

a photograph of metaphase chromosomes grouped in pairs

Question 24

nondisjunction

Answer 24

error in meiosis in which chromosomes fail to separate

Question 25

monosomy

Answer 25

type of nondisjunction in which one homologous chromosome is missing

Question 26

trisomy

Answer 26

type of nondisjunction in which there is an extra chromosome in a homologous pair

Question 27

sex chromosomes

Answer 27

23rd pair of chromosomes; XX or XY; determines sex of the offspring