MCDB 2171 (DISCOVERY LAB) EXAM
QUESTIONS WITH CORRECT ANSWERS
Homozygous - ANSWER-two of the same alleles for a gne
Phenotype - ANSWER-observable trait that results from genotype
Genotype - ANSWER-a description of the genetics of an individual
Maternal effect gene - ANSWER-a gene that determines the phenotype of the offspring
independent of the genotype of the offspring
Karyotype - ANSWER-an image of the chromosomes of an individual
Haploid - ANSWER-one copy of unpair chromosomes in a cell
Diploid - ANSWER-two copies of unpaired chromosomes in a cell
Loss of function - ANSWER-a mutation that causes the gene product has little or no
function
Gain of function - ANSWER-a mutation that causes the gene product to have altered
function, almost always a dominant train
Gametes - ANSWER-a haploid cell that fuses with another gamete during fertilization
Somatic cells - ANSWER-any cell other than a reproductive cell or gamete
EMS - ANSWER-a chemical capable of mutagenizing DNA, a carcinogen
Mutagenize - ANSWER-produce mutations in DNA
Phenotypic marker - ANSWER-an observable trait that indicates the genotype of an
organism
Balancer chromosome - ANSWER-an engineered chromosome used to prevent
crossing over and to maintain a homozygous lethal or sterile strain of flies
Crossing over - ANSWER-exchange of genetic material between two homologous
chromosomes
Syncytial division - ANSWER-nuclei of dividing cells during early Drosophila embryonic
development that share the same cytoplasm
, Cytokinesis - ANSWER-Process by which one cell is divided into two daughter cells, the
final stage of mitosis
Metacentric - ANSWER-centromere is located in the center of the sister chromatids
Telocentric - ANSWER-centromere is located at the end of the sister chromatids
Punnett square - ANSWER-diagram that determines the statistical probability of
offspring genotype
Dominant trait - ANSWER-a phenotype caused by one or two copies of a dominant
variant of a gene
Recessive trait - ANSWER-a phenotype caused by two copies of a recessive variant of
a gene
Heterozygous - ANSWER-two different alleles for a gene
Meiosis - ANSWER-the process of cell division that results in production of a gamete
Deleterious - ANSWER-causes harm or damage
Aneuploid - ANSWER-an abnormal number of chromosomes in an organism
Synapsis - ANSWER-joining of two homologous chromosomes at the beginning of
meiosis
4 - ANSWER-How many pairs of chromosomes do fruit flies have?
Drosophila melanogaster - ANSWER-What is the scientific name for the fruit fly?
10-14 - ANSWER-How many days does a life cycle take?
Egg - ANSWER-5 mm in length, hatches about one day after produced
Larva - ANSWER-legless, eats way through fermenting media, size increases 1 to
4mm. Crawls out of food and attaches to dry area after 6-8 days
Pupal case - ANSWER-cocoon in which compound eyes, jointed legs, and wings
develop
Adult - ANSWER-Emerges 10-14 days after egg appears
Male - ANSWER-sex of the fly with dark bristles around genital organs, sex combs on
forelegs, rounded abdomen, and black abdominal segments
QUESTIONS WITH CORRECT ANSWERS
Homozygous - ANSWER-two of the same alleles for a gne
Phenotype - ANSWER-observable trait that results from genotype
Genotype - ANSWER-a description of the genetics of an individual
Maternal effect gene - ANSWER-a gene that determines the phenotype of the offspring
independent of the genotype of the offspring
Karyotype - ANSWER-an image of the chromosomes of an individual
Haploid - ANSWER-one copy of unpair chromosomes in a cell
Diploid - ANSWER-two copies of unpaired chromosomes in a cell
Loss of function - ANSWER-a mutation that causes the gene product has little or no
function
Gain of function - ANSWER-a mutation that causes the gene product to have altered
function, almost always a dominant train
Gametes - ANSWER-a haploid cell that fuses with another gamete during fertilization
Somatic cells - ANSWER-any cell other than a reproductive cell or gamete
EMS - ANSWER-a chemical capable of mutagenizing DNA, a carcinogen
Mutagenize - ANSWER-produce mutations in DNA
Phenotypic marker - ANSWER-an observable trait that indicates the genotype of an
organism
Balancer chromosome - ANSWER-an engineered chromosome used to prevent
crossing over and to maintain a homozygous lethal or sterile strain of flies
Crossing over - ANSWER-exchange of genetic material between two homologous
chromosomes
Syncytial division - ANSWER-nuclei of dividing cells during early Drosophila embryonic
development that share the same cytoplasm
, Cytokinesis - ANSWER-Process by which one cell is divided into two daughter cells, the
final stage of mitosis
Metacentric - ANSWER-centromere is located in the center of the sister chromatids
Telocentric - ANSWER-centromere is located at the end of the sister chromatids
Punnett square - ANSWER-diagram that determines the statistical probability of
offspring genotype
Dominant trait - ANSWER-a phenotype caused by one or two copies of a dominant
variant of a gene
Recessive trait - ANSWER-a phenotype caused by two copies of a recessive variant of
a gene
Heterozygous - ANSWER-two different alleles for a gene
Meiosis - ANSWER-the process of cell division that results in production of a gamete
Deleterious - ANSWER-causes harm or damage
Aneuploid - ANSWER-an abnormal number of chromosomes in an organism
Synapsis - ANSWER-joining of two homologous chromosomes at the beginning of
meiosis
4 - ANSWER-How many pairs of chromosomes do fruit flies have?
Drosophila melanogaster - ANSWER-What is the scientific name for the fruit fly?
10-14 - ANSWER-How many days does a life cycle take?
Egg - ANSWER-5 mm in length, hatches about one day after produced
Larva - ANSWER-legless, eats way through fermenting media, size increases 1 to
4mm. Crawls out of food and attaches to dry area after 6-8 days
Pupal case - ANSWER-cocoon in which compound eyes, jointed legs, and wings
develop
Adult - ANSWER-Emerges 10-14 days after egg appears
Male - ANSWER-sex of the fly with dark bristles around genital organs, sex combs on
forelegs, rounded abdomen, and black abdominal segments
