Question

genotype and phenotype practice
name
introduction: recall that each organism inherits one allele for a gene from each parent. the combination of genes for an organism is called genotype. if the organism inherits two of the same gene, the genotype is homozygous. if it inherits two different genes, it is heterozygous. according to mendel, one of these will be dominant and will be expressed if it is present. it can mask the recessive trait. an organism can only express a recessive trait if it possesses two recessive traits. when recording genotype, two letters are used, a capital letter (d) for the dominant trait and a lower case (d) letter for a recessive. by knowing the genotype of an organism, you can identify its phenotype, how it looks.
homozygous dominant: kk homozygous recessive: kk heterozygous: kk
task: use the available information to identify the genotype and phenotype in each example.
1 for each genotype below, indicate whether it is heterozygous (he) or homozygous (ho)
aa
ee
ii
mm
bb
ff
jj
nn
cc
gg
kk
oo
dd
hh
ll
pp
2 for each of the genotypes below determine what phenotypes would be possible.
a. purple flowers are dominant to white flowers.

• pp
• pp
• pp

b. round seeds are dominant to wrinkled seeds.

• rr
• rr
• rr

c. brown eyes are dominant to blue eyes

• bb
• bb
• bb

d. bobtails in cats are recessive.

• tt
• tt
• tt

Explanation:

Step1: Recall Homozygous/Heterozygous Definition

Homozygous (Ho) has two identical alleles (e.g., AA, aa), heterozygous (He) has two different alleles (e.g., Aa).

Step2: Analyze Each Genotype

• AA: Same alleles (A,A) → Ho
• Ee: Different alleles (E,e) → He
• Ii: Same alleles (I,I) → Ho
• Mm: Different alleles (M,m) → He
• Bb: Different alleles (B,b) → He
• ff: Same alleles (f,f) → Ho
• Jj: Different alleles (J,j) → He
• nn: Same alleles (n,n) → Ho
• Cc: Different alleles (C,c) → He
• Gg: Different alleles (G,g) → He
• kk: Same alleles (k,k) → Ho
• OO: Same alleles (O,O) → Ho
• DD: Same alleles (D,D) → Ho
• HH: Same alleles (H,H) → Ho
• LL: Same alleles (L,L) → Ho
• Pp: Different alleles (P,p) → He

Answer:

Genotype	Homozygous (Ho) / Heterozygous (He)
Ee	He
Ii	Ho
Mm	He
Bb	He
ff	Ho
Jj	He
nn	Ho
Cc	He
Gg	He
kk	Ho
OO	Ho
DD	Ho
HH	Ho
LL	Ho
Pp	He