Final

Question 1

Complete dominance

Answer 1

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

Question 2

Incomplete dominance

Answer 2

The appearance of the heterozygous hybrid falls between the phenotypes of the two homozygous parents

Question 3

Codominance

Answer 3

Both alleles are expressed in heterozygous individuals and neither allele is masked by the other
(Different from incomplete dominance bc each trait in present separately)
(Ex. AB blood type)

Question 4

Pleiotropy

Answer 4

One gene influences multiple characters

Ex. sickle cell anemia

Question 5

Polygenic inheritance

Answer 5

Additive effects of two or more genes on a single phenotypic character
(Opposite of pleiotropy)

Question 6

Law of independent assortment

Answer 6

Inheritance of one character has no effect on the inheritance of another
Each pair of alleles sorts independently of other pairs of alleles during gamete formation
Physical basis in the orientation of homologous chromosome pairs in metaphase I

Question 7

Law of segregation

Answer 7

A sperm or egg cell carries only one allele for each inherited character bc alleles pairs separate during the production of gametes
Physical basis in the separation of homologues in anaphase I

Question 8

Linked genes

Answer 8

Genes located on the same chromosome, close together tend to be inherited together
Do not follow law of independent assortment

Question 9

wild type

Answer 9

The traits most common in nature

Question 10

Recombinant

Answer 10

Coming from two or more sources

Question 11

Testcross

Answer 11

a mating between an individual with an unknown genotype with an homozygous recessive individual

Question 12

Dihybrid

Dihybrid cross

Answer 12

heterozygous for both characters (RrYy)

Crossing these individuals with one another

Question 13

recombination frequency

Answer 13

Percentage of recombinant offspring in a generation

In linked genes, most offspring have parental phenotypes but some are recombinant (crossing over of heterozygous alleles)

Question 14

alleles

Answer 14

alternative versions of genes

Question 15

somatic cell

Answer 15

typical body cell containing 46 chromosomes

Question 16

homologous chromosomes

Answer 16

a pair of matching chromosomes that are twins in length and centromere position, carry genes controlling the same inherited characteristics
two chromosomes of a homologous pair may have different versions of the same gene

Question 17

locus

Answer 17

position on a chromosome where a particular gene is

Question 18

autosomes

Answer 18

non sex chromosomes found in 22 pairs in all humans

Question 19

diploid

Answer 19

all body cells contain 23 (in humans) pairs of homologous chromosomes
diploid number = 2n, 2n = 46

Question 20

gametes

Answer 20

sex cells containing a single set of chromosomes, 22 autosomes plus a sex chromosome

Question 21

haploid

Answer 21

sex cells contain 23 single chromosomes (one member of each homologous pair)
haploid number = n, n = 23

Question 22

fertilization

Answer 22

haploid sperm cell fuses with a haploid egg cell

Question 23

zygote

Answer 23

fertilized egg is diploid, one set of homologous chromosomes from each parent
23 maternal and 23 paternal chromosomes

Question 24

Activator proteins and enhancers

Answer 24

Activator proteins bind to other transcription factor proteins and enhancers and then bind as a complex at the genes’ promoter to facilitate the correct attachment of RNA polymerase = increased transcription = increased gene expression

Question 25

Transcription factors

Answer 25

proteins that assist eukaryotic RNA polymerase in gene expression

Question 26

Repressor proteins and silencers

Answer 26

Repressor proteins bind to DNA sequences called silencers and inhibit the start of transcription = decrease gene expression

Question 27

Photorespiration

Answer 27

Plants close their stomata when it is hot and dry to avoid losing water. They can't bring in CO2 and O2 builds up. Rubisco adds O2 instead of CO2 to RuBP

Question 28

Barr body

Answer 28

inactive X chromosome condensed

Question 29

Homeotic gene

Answer 29

master control gene that regulates batteries of other genes that actually determine the anatomy of parts of the body

Question 30

Signal transduction pathway

Answer 30

series of molecular changes that converts a signal on a target cell's surface to a specific response inside the cell

Question 31

The Central Dogma of DNA

Answer 31

DNA template Strand--->TRANSCRIPTION---> mRNA ---> TRANSLATION ---> Protein

Question 32

karyotype

Answer 32

ordered display of magnified images of an individual's chromosome arranged in pairs -produced from dividing cells arrested at metaphase of mitosis

Question 33

Euploid and Aneuplod

Answer 33

Normal chromosome number | Cells with extra or missing chromosomes

Question 34

haploid gamete + haploid gamete

Answer 34

ziploid

Question 35

unfertilized eggs are....

Answer 35

haploid(n)

Question 36

fertilized eggs

Answer 36

diploid (2n)

Question 37

trisomy 21

Answer 37

down syndrome | when there is an extra chromosome in pair 21

Question 38

nondisjunction

Answer 38

failure of chromosomes or chromatids to separate normally during meiosis. meiosis 1 in anaphase meiosis 2 in anaphase

Question 39

monohybrid cross

Answer 39

cross between 2 individuals differing in a single character

Question 40

Lysogenic cycle

Answer 40

Phages DNA remains dormant in the bacteria's DNA until triggered

Question 41

Lytic cycle

Answer 41

The phage DNA hijacks the bacteria DNA to produce phages until there are so many that the bacterial cell lyses and phages live on

Question 42

Transformation

Answer 42

One bacteria takes up and crosses over DNA with a dead bacteria

Question 43

Transduction

Answer 43

Phages insert another bacteria's DNA into a different bacteria by accident

Question 44

Conjugation

Answer 44

Sex bridge - two bacteria switch DNA

Question 45

Translocation

Answer 45

Non homologous chromosome segments swap places - causes leukaemia or some other bad thing