Ch. 13 SA

I would not want to invest in this way. It is assumed that the prize bull and cow will be reproducing sexually. Because of this, there is no way that the offspring will be the same as their parents. With sexual reproduction, the offspring always has a unique combination of DNA. Some of the award winning gene combinations could be the same, but there is a big chance that the offspring may not receive these award winning genes.

A cattle breeder claims that the future offspring from a prize bull and cow will be identical to the award winning offspring they've already produced. In fact, he's willing to sell you an investment opportunity on their next offspring. Assuming you had the money, discuss why you would or would not invest it this way.

The plants should be cloned asexually. This is because cloning asexually provides more of a chance of identical offspring to the parent plant. There are only 45 chromosomes too, so there will be an uneven match with the chromosomes if reproduced sexually.

A check of the genetics of a new African Violet plant shows that it has 45 chromosomes. (African violets are listed in the literature as 2N=30). To reproduce more award winning plants in the future, should it be breed sexually or clone it asexually? Explain.

Mitosis: - one division Synapses does not occur 2. Each diploid is identical Produces cells for growth and tissue repair Meiosis: - two divisions Synapses does occur 4. Each haploid is nonidentical Produces gametes Both: - DNA replication occurs in interphase

Contrast and compare meiosis to mitosis. Be sure to include several factors of similar/differences in your discussion. (hint - this question will be worth several points and could be set up in a table format)

The advantages of asexual reproduction is that you only need one parent, offspring are identical to the parent, and good genetic traits are conserved and reproduced. The disadvantages of asexual reproduction are that there are no DNA combinations for evolution to work on and clones may become extinct if attacked by a disease or pest. The advantages of sexual reproduction are that offspring has a unique combination of DNA which may be an improvement over both parents and there will be a new combination of DNA for evolution to work with. The disadvantages of sexual reproduction are that you need 2 parents, good gene combinations can be lost, offspring may not be an improvement over the parents.

Contrast and compare the advantages and disadvantages of asexual and sexual reproduction.

The karyotype of a human female differs from a male because it contains 2 X chromosomes. Males have 1 X and 1 Y chromosome.

Discuss how the karyotype of a human female differs from that of a human male.

I would choose a random assortment because the randomization of the genes is 3^23. That randomization allows for thousands of different genes. This allows for many more different traits to be expressed, which can bring evolutionary advantages.

The Genetic Genie in the DNA bottle has granted you just one wish for hybridizing mice. You can create variation in your mice by random assortment of chromosomes, random fertilization, or crossing-over. Which method do you choose? Explain.

Because crossing over cannot be used, we could use independent assortment. With independent assortment, we could generate 2 gamete cells. Because the diploid number for fruit flies is only 8 compared to the diploid number of 32 for pillbugs, pillbugs will produce a greater variety of zygotes.

The diploid number for fruit flies is 8 while that for pillbugs is 32. If no crossing over took place, would the genetic variation among offspring from a given pair of parents be greater in fruit flies or pillbugs? Explain.

The chromosomes in a cell at metaphase of mitosis are similar to the chromosomes in a cell at metaphase of meiosis 2. During metaphase in mitosis, the chromosomes are attached with spindle fibers and are lined up in the middle of the cell. During metaphase of meiosis 2, the chromosomes are attached with spindle fibers in the middle of the metaphase plate as well. In metaphase of meiosis 2, it seems as there are 2 pairs of chromosomes on opposite sides of the cell, so they are able to readily split.

Describe how the chromosomes in a cell at metaphase of mitosis are similar to and/or different from the chromosomes in a cell at metaphase of meiosis II.

Crossing over during meiosis would not contribute to the genetic variation among daughter cells because the DNA from the mom and dad may be identical. If this happens, when the chromosomes recombine, they will be equal when the different alleles are rearranged.

Describe under what circumstances crossing over during meiosis would NOT contribute to the genetic variation among daughter cells.

I have learned from this chapter that children should not always look just like their parents. This is because there are so many different gene combinations through mitosis, like billions and billions. This makes it almost impossible to look like your parents.

Discuss the statement "children should always look just like their parents" from what you know from this chapter.

Sexual reproduction would be the "best" strategy for continuing a species through time. This is because sexual reproduction provides a unique combination of new DNA for evolution to work with. Asexual reproduction has the same genes with no variation, and there is a potential for the good genes to be lost. There can be more evolutionary advantages with sexual reproduction compared to asexual reproduction.

Discuss which type of reproduction is the "best" strategy for continuing a species through time. Be sure to defend and explain your logic.