Human+Genetics+DB



(1) Define: genotype- the genes of an individual

alleles- alternative forms of a gene having the sae position on a pair of chromosome and affecting the same trait

dominant allele- assigned an uppercase letter

recessive allele- assigned a lower case letter

locus- a pair of homologous chromosomes

homozygous dominant- both alleles are dominant traits

phenotype- physical apearance of an individual

homozygous recessive- two recessive alleles

heterozygous- a recessive and a dominant allele

(2) What is the difference between genotype and phenotype? Genotype is the genes of a person while phenotype is how those genes show themselves physically.

(3) What are the three possible genotypes and two possible phenotypes for a characteristic that is controlled by two alleles, one being dominant and the other recessive? Three different genotypes are WW, Ww, and ww. WW or Ww gives a person a widow's peak and ww gives a person a straight hairline.

(4) For each of the following genotypes, give all the possible gametes. WW- only W WWSs- WW,WS,Ws,Ss Tt- T,t Ttgg- Tg, tg AaBb- AB, Ab, Ba, ba

(5) For each of the following, state whether  a genotype or a  gamete is represented. D- gamete Ll- gamete Pw- phenotype LlGg- phenotype



(6) What is the genotype of the individual from the following crosses? ES x es- EsSe eS x es- esSe

(7) Define monohybrid- heterozygous with regards to one pair of alleles

Punnett square- every possible combination of gametes occurs within squares of a chart

(8) A man with a wiidow's peak has a mother witha a straight hairline. Widow's peak (W) is dominant over straight hairline (w). What is the genotype of the man? His genotype is Ww.

(9) Both a man and a woman are heterozygous for freckles. Freckles (F) are dominant over no freckles (f). What is the chance that their child will have freckles? 1/4

(10) Both you and your sister or brother have attached earlobes, yet your parents have unattached earlobes. Unattached earlobes (E) are dominant over attached earlobes (e) What are the genotypes of your parents? Ee Ee