Reference no: EM132386680

Assignment: Reproductive Systems
key concepts: sexual selection, sexual dimorphism, male competition, female choice, sexual conflict

Part 1: Write a comment for the one of the question below. (150-200 words) Please only use the source what provided. And Please use the own word and use the 1st subject to write the comment. Please notice , which question you are answer.

As you know, the sex of a human is determined genetically: females are XX (they have two X chromosomes), males are XY (they have one X and one Y chromosome). In birds, sex is also determined genetically, but with the opposite pattern: females are ZW and males are ZZ. We'll see later that in other animals, sex may be determined by social conditions or even temperature. (Yet another issue with global warming.)

Vide: Lizard sex switch (By University Of Canberra)

Given this variability in how sex is determined, how do we know which animals are females and which are males? Well, it all comes down to the individual's gamete (or sex cell): females produce eggs, males produce sperm.

For this discussion, let's try to think through why there are egg and sperm. You can use your intuition because the differences between eggs and sperm in humans are the same for other animals. So what are the differences? (Please just answer one question.)

• What are their differentiating characteristics (under a microscope, how would you distinguish them)?

• Why do you think animals evolved two different gametes. Sexual reproduction requires two gametes, but why should they be different?

Hint: Consider the function of the differentiating characteristics from the previous question.

• What are the differences in the availability of egg and sperm (how often and how much)?

• How might the differences between egg and sperm lead to differences in mating behavior?

• If your group answers all of these question, you might discuss some of the other ways that males and females make different investments in their offspring. (Often females invest more, but that's not always true. Consider, for example, seahorses. What's unusual about the roles of male and female seahorses?) However you answer this, try provide a specific example.

Part 2- Answer the Q1-7

1. According to the video: mPaul Bloom: The Psychology of Everything (By Big Think) monkeys would choose to sip orange juice rather than to look at photos, unless the photos showed

A : fruits
B : a high status male
C : a newborn
D : all of the above

2. Natural Selection & Sexual Selection: An Illustrated Introduction (By Cornell Lab of Ornithology) ,In sexual selection, traits become more or less common depending on

A : which sex they benefit most, males or females
B : whether they allow control of the sex of offspring
C : whether they allow an individual to mate with more or better partners

3. Natural Selection & Sexual Selection: An Illustrated Introduction (By Cornell Lab of Ornithology), The distribution of food influences the form of sexual selection. Which of these pairs is correct?

A : dispersed food leads to male-male competition
B : clustered food leads to female choice
C : clustered food leads to male-male competition

4. Tap dancing bird finally recorded (By Science Magazine), The male bird in the video tries to attract a mate using everything EXCEPT:

A : holding nesting material in his beak
B : tap dancing
C : singing
D : acrobatic flight

5. Male pregnancy: The dark side - by Nature Video (By nature video), Male pipefish prefer large females, so what happens when a male encounters a smaller, less attractive female

A : He refuses to mate with her.
B : He only pretends to mate with her.
C : He mates with her but doesn't invest resources in the eggs
D : He mates with her but ejects the eggs as soon as she swims away

6. Compared with male mammals, female mammals make a greater investment in their offspring (they carry them through gestation and they produce milk). Can you think of a reason why females might be more motivated than males to invest in their offspring? (The answer has to do with kin selection. Remember, a child is equally related to its mother and its father. So what's the difference? If the answer doesn't come to you immediately, let it sit in the back of your mind for a bit. Once you think of it, you'll see that the answer is obvious.)Please only use the source what provided above. And Please use the own word to answer.

7. The more colorful a male bird, the more conspicuous he is to predators. So how could being colorful be adaptive?Please only use the source what provided above. And Please use the own word to answer.

Part 3- Write a comment for the one of the question below. (150-200 words) Please only use the source what provided. And Please use the own word and use the 1st subject to write the comment. Please notice , which question you are answer.

We've seen that when it comes to mating, males and females often have different agendas Males vs. Females: Sexual Conflict (By MinuteEarth). This difference can lead to conflict between the sexes. Discuss the origin of the conflict (why are the males and females in opposition) and the way the conflict plays out (what strategies do the males and females use to advance their respective agendas). In addition to the specific strategies discussed in the video, you can discuss these strategies:

Why Female Dragonflies Go to Extreme Lengths to Avoid Sex (By Sandhya Sekar)

Females Stop Sneaky Males From Fertilizing Their Eggs

Ultimate sacrifice: Spider's post-sex cannibalism aids offspring (By National Science Foundation)

Flatworm Penis Fencing | World's Weirdest (By Nat Geo WILD)