Genetics Test 1

Front 1

DNA is a single strand copy of a gene found in the genetic materials and is translated into a protein

Back 1

false- RNA

Front 2

mRNA is a molecule that carries the genetic info from DNA and as used as a template for protein synthesis

Back 2

true

Front 3

Eukaryotic cells differ from prokaryotic cells in that only the former contain a nucleus

Back 3

true

Front 4

DNA duplication takes place in the M phase of the cell cycle

Back 4

false- s phase

Front 5

In a karyotype, the location of the breast cancer susceptibility gene (BRCA1) is given as 17q21. This means the gene is located on chromosome 21.

Back 5

false chromosome 17

Front 6

meiosis minimizes genetic variation among sexually reproducing populations

Back 6

false- meiosis maximizes genetic variation

Front 7

in a testcross, the unknown genotype is crossed with a homozygous recessive individual to determine genotype

Back 7

true

Front 8

pleiotropy happens when the phenotype can be influenced by many genes

Back 8

false- epistasis.....pleiotropy is one gene affects many phenotypes

Front 9

if recombination frequency is 30.5% the distance between these two genes is 30.5 cM

Back 9

true

Front 10

genes that are tightly linked recombine often

Back 10

false- linked recombine occasionally

Front 11

in eukaryotic cells, DNA is only found in the nucleus

Back 11

false- mitochondria, chloroplasts

Front 12

alternative forms of a gene are called a locus

Back 12

false- allele

Front 13

meiosis- 4 haploid
mitosis- 2 diploid

Back 13

true

Front 14

human genome has 24 pairs of chromosomes

Back 14

false- 23 pairs

Front 15

what is correct order from smallest level?:
chromosome, genes, genome, nucleotides

Back 15

nuleotides
genes
chromosome
genome

Front 16

what are dna base pairs?
rna base pairs?

Back 16

A/T and C/G
A/U and C/G

Front 17

a process that occurs in meiosis but not in mitosis?

Back 17

pairing of homologous chroms

Front 18

crossing over happens during which stage of cell division

Back 18

prophase 1

Front 19

for any given gene, the principle of segregation predicts that gametes produced as a result of meiosis will contain

Back 19

a single allele of a gene pair

Front 20

the interaction between non-allelic genes in their effects on a trait is called

Back 20

epistasis

Front 21

in a pop carrying a dominant mutant allele, only 70% of the people carrying the allele show the phenotype. this exhibits

Back 21

incomplete penetrance

Front 22

in dihybrid crosses, 9:3:3:1 indicates

Back 22

independent assortment

Front 23

a cross between two heterozygotes for one trait yields a phenotypic ratio of 2:1. whats the best explanation?

Back 23

the dominant trait is lethal in homozygous form

Front 24

in maize the genes A and B are so tightly linked that virtually no crossovers occur between them. a dihybrid Ab/aB is testcrossed to ab/ab. the percentage of progeny with A-B- genotype will be?

Back 24

0%

Front 25

when only males exhibit a recessive trait this is called

Back 25

x linked recessive

Front 26

maximum recombination frequency between two genes is

Back 26

50%

Front 27

compared to heterochromatin, euchromatin is ...

Back 27

less densly stained and less densly packed

Front 28

the failure of chromosomes to separate during meiosis is known as what?

Back 28

non-disjunction

Front 29

in a sweet pea experiment progeny revealed a ratio of roughly 23:1:1:7. this is an idication of what basic trait?

Back 29

linkage

Front 30

crossing over occurs in which stage of meiosis 1?

Back 30

pachynema

Front 31

what happens to chromosomes in each stage?
leptonema
zygonema
pachynema
diplonema
diakinesis

Back 31

chroms are already duplicated
pairing is initiated
pairing and crossing over
held by centromere and
repulsion begins
chroms move to equitorial plane

Front 32

recombinant chromosome

Back 32

when two different chromosomes are next to each other and they trade genes "crossing over"

Front 33

linkage

Back 33

genes on same chromosome

Front 34

coupling

Back 34

homologous linkages (dominant or recessive)

Front 35

repulsion

Back 35

heterozygous linkage (dominant linked to a recessive)

Front 36

crossing over is ______ likely to occur if genes are close together on a chrom

Back 36

less

Front 37

crossing over is ______ likely to occur if genes are far apart on a chrom

Back 37

more

Front 38

to test for recombination/crossing over, what is crossed with what?

Back 38

heterozygous female with a homozygotus recessive male

Front 39

if crossing over occurs progeny will be...

Back 39

50% wild type
50% mutant cross overs

Front 40

in drosophila, recombination is not seen in

Back 40

the male flies

Front 41

interface

Back 41

the difference between the observed and expected crossovers.
1-(observ/expected)