Dr. Rosato L1

Question 1

meaning of “diploid”

Answer 1

two copies of each gene/chromosome, one from maternal and one from paternal

Question 2

meaning of “haploid”

Answer 2

one copy of each gene/chromosome such as sperm/egg/gamete

Question 3

meaning of “gene”

Answer 3

a fragment of DNA encoding RNA

Question 4

meaning of “Alleles”

Answer 4

> alternative forms of same gene

> pair of genes on a chromosome that determines characteristics such as hair colour

Question 5

meaning of “homologous”

Answer 5

same gene in different species

Question 6

meaning of “homologues”

Answer 6

copies related by descent

Question 7

meaning of “homolog”

Answer 7

anything the same, same function

Question 8

meaning of “orthologs”

Answer 8

type of homolog that are a result of speciation

Question 9

meaning of “paralogs”

Answer 9

type of homolog that is a result of duplication

Question 10

meaning of “analogous”

Answer 10

similar function but having a different evolutionary origin, such as the wings of insects and birds.

Question 11

meaning of “genotype”

Answer 11

specific allele composition

Question 12

meaning of “phenotype”

Answer 12

form that is seen- characteristics such hair colour, given by genotype

Question 13

meaning of “haplotype”

Answer 13

DNA variations (polymorphisms) that tend to be inherited together from a single parent

Question 14

meaning of incomplete dominance

Answer 14

Incomplete dominanceis a form of intermediate inheritance in which one allele for a specific trait is not completely expressed over its paired allele. This results in a third phenotype in which the expressed physical trait is a combination of the phenotypes of both alleles.

For example, If you had a blue allele and a yellow allele then the outcome would be neither blue or yellow but would be green due to mixture of both and none being dominant over the other, because the outcome is green, which is a 3rd phenotype

Question 15

meaning of homozygote

Answer 15

same

Question 16

meaning of heterozygote

Answer 16

different

Question 17

meaning of co-dominance

Answer 17

both alleles contributing to the phenotype

for example if you had blue and yellow, the outcome of a co-dominance would be blue and yellow (blue flower with yellow dots)

Question 18

example of disease caused by dominant mutation

Answer 18

> dwarfism

> huntingtons disease

Question 19

where is the mutation that causes dwarfism?

Answer 19

Fibroblast growth factor receptor 3 (FGFR3) gene which causes an abnormality of cartilage formation

Question 20

Huntington’s disease gene info

Answer 20

> gene has CAG repeats (polyglutamine)
normal gene has 6-39 CAG repeats
disease gene has 35-121 CAG repeats

Question 21

possible molecular explanations of dominant mutations

Answer 21

> not enough protein made if only one gene copy is active

> genes constantly expressed

Question 22

meaning of Epistasis

Answer 22

interaction of two or more genes on separate chromosomes which effect the phenotype