Answer:
X-linked recessive inheritance
Explanation:
Since the disease is primarily present in males vs females, it is a s.ex linked disease.
In X-linked recessive inheritance, males tend to get disease b/c they only have one x (the other is y) which means if they get the bad "x" copy from mom then they definetely will get the disease.
Females can be carriers b/c they are XX. If they get a good copy from mom and suppose a bad copy from dad, they can still be healthy b/c the good copy is dominant. They will be carriers (cuz they have the bad copy) but themselves wont have the disease.
9:3: 3:1 is the phenotypic ratio showing traits as black and long hair : black and short hair: chestnut and long hair: chestnut and short hair when a chestnut horse heterozygous for pacing and hair length with a hybrid horse.
Explanation:
Dominant trait = black hair colour (BB,Bb), trotting (TT,Tt) , long hair (LL,Ll)
recessive trait = chesnut hair colour (bb), pacing gait (tt), short hair(ll)
cross between chestnut horse heterozygous for pacing and hair length will have alleles as BbLl
alleles for hybrid horse will also be heterozygous Bb, Ll
Punnett square to show the cross:
BL Bl bL bl
BL BBLL BBLl BbLL BbLl
Bl BBLl BBll BbLl Bbll
bL BbLL BbLl bbLL bbLl
bl BbLl Bbll bblL bbll
phenotype ratio
black and long hair : black and short hair: chestnut and long hair: chestnut and short hair
9:3: 3:1 is the phenotype ratio.
No but thank you for the free eight points