Genetics Vocab

Question 1

Dominant

Answer 1

If the dominant allele is present in an offspring, the dominant trait will show up in the offspring

Question 2

recessive

Answer 2

This trait will show up in the offspring only if the dominant allele is not present

Question 3

allele

Answer 3

Different versions of a gene that produce distinguishable traits in offspring

Question 4

gene

Answer 4

A segment of DNA that controls a hereditary trait

Question 5

test cross

Answer 5

used when you don’t know the genotype of 1 parent

Question 6

punnett square

Answer 6

determines genotypic and phenotypic ratios

Question 7

chromosome

Answer 7

long chain of genes

Question 8

Heterozygous

Answer 8

the two alleles are different: Tt

Question 9

homozygous

Answer 9

the two alleles are the same: TT or tt

Question 10

law of segregation

Answer 10

The alleles for one trait segregate independently of the alleles for another trait, when the genes are located on separate, nonhomologous chromosomes

Question 11

nondisjunction

Answer 11

the members of a pair of homologous chromosomes do not move apart properly during meiosis I, or sister chromatids fail to separate during meiosis Il

Question 12

independent assortment

Answer 12

when alleles separate from each other in meiosis; creates genetic variation

Question 13

law of dominance

Answer 13

if the dominant allele is present it will mask the recessive allele, therefore only the dominant phenotype is expressed

Question 14

incomplete dominance

Answer 14

neither allele is dominant nor recessive; traits all blend together (variations of letters: RR, Rr, Rr)

Question 15

codominance

Answer 15

both alleles are dominant, so both traits show up at the same time (all capital letters but 2 different

Question 16

sex-linked

Answer 16

found on the X chromosome; traits are more common in males because they only get 1 copy of the X chromosome

Question 17

carrier

Answer 17

women: X^N X^n men: cannot be a carrier

Question 18

hemophilia

Answer 18

Disorder that prevents clotting when bleeding (sex-linked recessive)

Question 19

sex chromosome

Answer 19

2 of them (XX or XY)

Question 20

autosome

Answer 20

body chromosomes; everyone should have 22

Question 21

XX

Answer 21

female

Question 22

XY

Answer 22

male

Question 23

hybrid

Answer 23

heterozygous (Tt)

Question 24

true breeding

Answer 24

homozygous dominant (TT)

Question 25

purebred

Answer 25

Homozygous recessive (tt)

Question 26

blood type

Answer 26

A, B, AB, O

Question 27

multiple alleles

Answer 27

more than 2 alleles are available for each gene; each person can only have 2 (1 from each parent) there are more possible combinations

Question 28

turner syndrome

Answer 28

Females - They are missing an X chromosome
Affects development and many are infertile
(Nondisiunction of the sex chromosome; 23rd pair)

Question 29

klinefelter’s syndrome

Answer 29

Males - Extra X chromosome (XXY) Affects development and many are infertile
(Nondisjunction of the sex chromosome….23rd pair)

Question 30

trisomy 21

Answer 30

A genetic condition caused by having an extra chromosome 21 in some or all of the body’s cells

Question 31

polygenic traits

Answer 31

Traits that are controlled by 2 or more genes (EX: height, skin color, hair color, eye color)

Question 32

karyotype

Answer 32

picture of a persons chromosomes, arranged by homologous pairs

Question 33

sickle cell anemia

Answer 33

Some red blood cells are shaped like a sickle and are unable to transport oxygen throughout the body (autosomal recessive)

Question 34

pedigree

Answer 34

genetic representation of a family tree that diagrams the inheritance of a trait or disease through several generations