Animal Reproduction Questions
Bring on the tough stuff
1) What are three differences in sexual and asexual reproduction?
2) Name two differences in sperm and egg production.
3) Why would an animal travel to a special breeding ground?
4) Animal A is iteroparous. Animal B is semelparous. Who will produce more offspring in their lifetime?
5) Why would a polyspermy block be more important in external fertilization?
6) Draw out the stages of embryo development.
7) What are the benefits of marsupial birth?
8) What might happen if a human found a bird egg, hatched it, and raised it?
9) If there were no recombination during meiosis, how would the gametes be different?
10) What is the benefit of a long peacock tail?
Possible Solutions
1) What are three differences in sexual and asexual reproduction?
Sexual reproduction requires a union of gametes and provides a unique diploid individual. It produces diversity and allows for more than one offspring at a time.
Asexual reproduction requires one parent. There is not a union of gametes. The diploid parents create a diploid offspring through fission, regeneration, parthenogenesis, or budding. It usually creates only one offspring at a time.
2) Name two differences in sperm and egg production.
Sperm production is called spermatogenesis. It happens in males. It creates many sperm continuously. Egg production is called oogenesis. In mammals it produces less eggs at a time according to a hormone cycle. It also has an arrest period between birth and puberty and it creates polar bodies.
3) Why would an animal travel to a special breeding ground?
An animal would travel to a special breeding ground to meet mates who it does not see the rest of the year. It might also go there to use the great resources for feeding its young or building its den or its nest. It also might go for the weather like some turtles who need warm sand for their eggs to develop.
4) Animal A is iteroparous. Animal B is semelparous. Who will produce more offspring in their lifetime?
It is impossible to tell. Animal B might produce millions of offspring only one time. Animal A may produce 10 offspring a hundred times. That would mean Animal B still produces more even though it only reproduces one time. Unless we know how many offspring each animal gives birth to each time, then we do not know.
5) Why would a polyspermy block be more important in external fertilization?
A block to polyspermy is important in external fertilization because there are many animals with access to the gametes in the water. In internal fertilization it is less likely that different species will be copulating (although it happens).
6) Draw out the stages of embryo development.
They should look something like this picture. If you got 1-cell, 2-cell, morula, blastula, and gastrula then give yourself full credit.
7) What are the benefits of marsupial birth?
Marsupials give birth when their young are super young. This means that they give birth really easy compared to other mammals. Imagine how easy human birth would be if the baby came out the size of a jellybean? Of course, they still keep them close and safe, but the tight squeeze happens so soon that it is not really a tight squeeze at all!
8) What might happen if a human found a bird egg, hatched it, and raised it?
The bird might imprint on the human. It might not learn how to properly be a bird. It might think the human is its mother. There are many stories of birds that have been raised by humans since they were hatchlings and have become quite attached to them.
9) If there were no recombination during meiosis, how would the gametes be different?
The gametes would be less diverse. Certain traits from the mother that are on the same chromosome will always be packaged together. It will be impossible to pass on one trait and not the other. There would still be diversity because of the combining of mother and father gametes, but it would not be nearly as diverse as it is now. Recombination is important for diversity.
10) What is the benefit of a long peacock tail?
A long peacock tail does not help a peacock survive, but it helps him to be more sexy. Female peacocks like a long tail. Usually, traits that help survival and health are the same traits that are favored…but not this tail. It helps them find a mate so much that it is naturally selected for. It gets even longer every year.