Unit 3

Question 1

Karyotype

Answer 1

an ordered display of the pairs of chromosomes from a cell

Question 2

Homologous chromosomes

Answer 2

2 chromosomes in each pair, same shape and same genes

Question 3

Diploid cell

Answer 3

has 2 sets of chromosomes (2n). Normal eukaryotic organism. Humans have 46

Question 4

Haploid cell

Answer 4

half the number of chromosomes

Question 5

Gamete

Answer 5

(sperm or egg) contains a single set of chromosomes and is thus a haploid cell. Only type of human cells produced by meiosis, rather than mitosis

Question 6

Zygote

Answer 6

Fertilized egg

Question 7

Meiosis 1

Answer 7

Separates homologous chromosomes

Question 8

Meiosis 2

Answer 8

Separates sister chromatids

Question 9

Meiosis

Answer 9

reduces the number of chromosome sets from two (diploid) to one (haploid), producing cells that differ genetically from each other and from the parent cell

Question 10

Mitosis

Answer 10

conserves the number of chromosome sets, producing cells that are genetically identical to the parent cell

Question 11

Crossing over

Answer 11

occurs between prophase 1 and metaphase 1 and is the process where homologous chromosomes pair up with each other and exchange different segments of their genetic material to form recombinant chromosomes

Question 12

Recombinant chromosomes

Answer 12

combine DNA inherited from each parent

Question 13

True breeding

Answer 13

plants that produce offspring of the same variety when they self pollinate

Question 14

Hybridization

Answer 14

mating of 2 contrasting, true-breeding varieties

Question 15

The law of segregation

Answer 15

states that allele pairs separate or segregate during gamete formation, and randomly unite at fertilization

Question 16

Allele

Answer 16

Alternative version of a gene

Question 17

Independent assortment

Answer 17

each pair of alleles segregates independently of any pair of alleles during gamete formation

Question 18

Incomplete dominance

Answer 18

the phenotype of F1 hybrids is somewhere between the phenotypes of the two parental varieties. Not blending because recessive genotype/phenotype can be separated

Question 19

Codominance

Answer 19

two dominant alleles affect the phenotype in separate, distinguishable ways

Question 20

Pleitophy

Answer 20

multiple phenotypic effects

-cystic fibrosis and sickle cell anemia

Question 21

Epistasis

Answer 21

expression of a gene at one locus alters the phenotypic expression of a gene at a second locus

Question 22

Quantitative characters

Answer 22

are those that vary in the population along a continuum. Uses polygenic inheritance

Question 23

Polygenic inheritance

Answer 23

an additive effect of two or more genes on a single phenotype

Question 24

Carrier

Answer 24

heterozygous individuals who carry the recessive allele but are phenotypically normal

Question 25

Aminocentesis

Answer 25

the liquid that bathes the fetus is removed and tested

Question 26

Chorionic villus sampling

Answer 26

a sample of the placenta is removed and tested

Question 27

Chromosome theory of inheritance

Answer 27

Identifies chromosomes as the carrier of genes | - Sutton and Boveri

Question 28

Nondisjunction

Answer 28

Pairs of homologous chromosomes do not separate normally during meiosis -as a result, only one gamete receives two of the same types of chromosome, and another gamete receives no copy

Question 29

Aneuploidy

Answer 29

results from the fertilization of gametes in which nondisjunction occurred - offspring with this condition have an abnormal number of a particular chromosome - aneuploid condition

Question 30

Mono sonic zygote

Answer 30

Has only one copy of a particular chromosome

Question 31

Trisomic zygote

Answer 31

has 3 copies of a particular chromosome | -ex trisomy 21, Down syndrome

Question 32

Polyploidy

Answer 32

a condition in which an organism has more than two complete sets of chromosomes - triploidy: 3 sets - tetraploidy: 4 sets

Question 33

Deletion

Answer 33

Removes a chromosomal fragment

Question 34

Duplication

Answer 34

Repeats a segment

Question 35

Inversion

Answer 35

Reverses orientation of a segment within a chromosome

Question 36

Translocation

Answer 36

Moves a segment from one chromosome to another

Question 37

Genomic imprinting

Answer 37

Phenotype variation, the phenotype depends on which parent passed along the alleles for those traits