Question

can someone explain how a is sex-linked and c is autosomal.

also, need help with e please.

Your hobby is breeding fancy guinea pigs for people who like that sort of thing. You set up a cross in which the parents are true-breeding and have phenotypes as follows: the father has black fur and a long tail, and the mother has white fur and is tailless. They produce offspring in which all the males are white and have long tails and all the females are grey with long tails. a. Is fur color autosomal or sex linked? Sex-linked b. Describe which fur color phenotypes are dominant, recessive, co-dominant, or incompletely dominant where appropriate. Dominant is white. Recessive - Black Incompletely dominant- Grey C. Is tail length autosomal or sex linked? Autosomal d. Describe which tail length phenotypes are dominant, recessive, co-dominant, or incompletely dominant where appropriate. Dominant: Long tailed Recessive-Tailless e. What phenotypic ratios do you expect in the F2?

Answer 1

Tips to identify if the given trait is autosomal or sex-linked:

I. In autosomal trait, number of affected male and females are equal, unlike in sex-linked, in which number of affected males are overwhelming.

II. In autosomal trait, both male and female individuals could be the carrier. Unlike in sex-linked, in which always females are the carriers, never the males.

COMING BACK TO THE QUESTION:

QUESTION: a,b,c and d

​​Cross: both parents are pure breeds

Let, W - white fur

w - black fur

T - long tail

t - tailless.

Crossing between:

male ( black fur, long tail) X female ( white fur, tailless)

Offsprings: All males - white fur and long tails

All females - grey fur and long tails.

After seeing the F1 generation, we can say that fur color white is dominant, black is recessive and grey is incomplete dominance (white and black fur got blended).

Also, fur color is sex-linked, since all the males are affected with the recessive trait but none of the female and only the females are carrier of the recessive trait (hence the grey color).

*Long tail is dominant over tailless, since all the offsprings have long tails.

Also, tail length is autosomal, since number of tailless male and female are same and both male and females are carriers.

FURCOLOR FEMALE thy - male with white fur the two female with grey fur MALE (incomplete dominances TAIL LENGTH: FEMALE MALE IT Tt TU! T It - long tail i dominant oveo + TI Tt T is dominant oveo t

QUESTION E:

F2 generation: white fur long tail male X grey fur long tail female.

PHENOTYPIC RATIO : 6:3:3:2:1:1

Cross : x","т у хуть х"т «* *"T — x°E XWE XWXNTt x W x H xyloft Xytt ут ѓутт х*уть сутт х"уть yt hy Tt Xhlytt xwy Tt x Wytt

6 (WHITE FUR-LONG TAIL): 3 (GREY FUR-LONG TAIL): 3 (BLACK FUR-LONG TAIL): 2 (WHITE FUR-TAILLESS): 1 (GREY FUR-TAILLESS): 1 (BLACK FUR-TAILLESS)