Instructions:
Read the information below regarding the topic for this chapter.
Answer and/or respond to the questions and topics below in a new discussion thread. This will be your “initial post”.
Your initial posting should reflect your thought on the subject and be thorough. Use complete sentences and refrain from slang. Responses should be a minimum of 2 paragraphs.
Respond to at least 2 other posts on the discussion forums.
Your responses to other students should be thoughtful and respectful. Refrain from short responses like “good job” or “I liked your post”. Instead follow that up with why it was a “good job” or why you liked it.
Chapter 4 Discussion
Watch the 5 minute video below on sex determination in animals.
https://www.youtube.com/watch?v=kMWxuF9YW38
Why do you think there are so many different sex determination systems? What might be some of the advantages and disadvantages of different kinds of sex determining systems (pick one of them)?
Critical thinking question: Why are there only 2 sexes? Why not more than 2?
Initial Post
Respond to the questions above in a new thread in the discussion forum.
Respond to 2 other posts
Respond to two other student posts reflecting on their responses. Did you agree or disagree? Why? Was it something you had considered? Is there maybe something they should consider?
Post 1:
The reason for there being different sex determination systems is evolution. Humans have both males and females that contribute to reproduction in our species, but of course not every species is similar. Like in lizards from out previous discussion, some species only need females to reproduce and do not require the input of a male. Having different sex determination systems creates diversity between species like shown above. The disadvantage to having only females in a species or only males can lead to extinction and there will not be as many mutations and diversity withing the species. I thought it was intriguing to learn about the clown fish and how all are born as males but then can evolve into females. Advantages to having different systems for species is that it could make it easier to find mates, or to reproduce without mates easily.
Intersex can create more variations within a species but can also make it hard to comeby mates. This would then lead to making it harder to reproduce and keep numbers high in species populations. Having only two sexes who reproduce together make it easier to find mates, and can help in expanding genetic variation in the population.
post 2:there are multiple sex determining systems due to evolution. Organisms have evolved and changed with their environment over time. And due to many organisms living in many different environments, the creation of different sex determining systems have formed based on what has best for an organism in a particular environment.
One type of sex determining system is the environmental system, this system relies on specific properties on the environment to decide on whether an offspring is male or female, the benefit to this system that it only allows for only offsprings that are tolerant of the environment. The done side to this system is that if the environmental factor doesn’t change it will only allow for one sex to reproduce.
As for the question of why there are only two sexes, I believe that there are only two because it allows for genetic diversity and the reproductions of offspring without getting too complicated.
