Question

4. You are working on a certain species of worm, with an ZZZW sex determination system. You perform karyotype analysis for a mating pair, but you don't know which one is the male and which one is the female. Which one would you guess is the female (left or right?) (2points) ) 5. Different genes are located on different kinds of genetic elements - autosomes, W chromosomes, the mitochondrial genome, etc. Different elements are transmitted in different ways, so different parents transmit different elements to different offspring. For each case, answer 'both sons and daughters, 'only sons, only daughters, or neither sons nor daughters. For instance, fathers transmit autosomal genes to both sons and daugthers, but fathers inherit Y chromosome genes to only sons. If a parent is not expected to have such genes, answer 'neither sons nor daugthers. (1 point per answer) Mothers transmit Y chromosome genes to: Fathers transmit X chromosome genes to: Mothers transmit mitochondrial genes to: Mothers transmit Z chromosome genes to: Mothers transmit W chromosome genes to: 6. Anurak is a man who is effected with a disease caused by a mutation in an imprinted gene that is paternally-expressed (maternally silenced). Anurak and his female partner are considering having a child. Imagine you are a genetic counseler. Do you tell them they should worry about their child having the disease or not? Why? (2 points) Anurak's mother is considering having a child with her new male partner (not Anurak's father). Imagine you are a genetic counseler. Do you tell them they should worry about their child having the disease or not? Why? (2points) Anurak remembers hearing that one of his parents' grandmothers had the same disease, but he can't remember which parent. Do you think it was his mother's grandmother or his father's grandmother? (points) Is it surprising that his great-grandmother had the disease, given that she is a female? Why? (2 points)

Answer 1

4. Female is on left and male is on right.

In worms, ZZ is male and ZW is female. Males are homogametic and females are heterogametic.

In a karyotype, sex chromosomes are placed in the end. So, to determine the sex of the individual from a karyotype, you only need to look at the last two chromosomes.

​​​​​​5. To answer this questions, first know the background :

In worms, autosomes are present. Both male and female parent contribute equally to autosomes present in the progeny.

Female gives either Z or W and males give Z to the progeny.

Mitochondria and cytoplasm is donated by the mother.

Answers :

None of the progeny

None of the progeny

Both son and daughter

Both son and daughter

Only to daughter

Please rate high.

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