Questions to Ponder Exam 1
Key: Purple = My initial thoughts Red = Vigna's answer
1. What are the main parts of a cell and what are their jobs?
Nucleus: holds the genetic information, control center of the cell
ER: Rough - Covered by Ribosomes that produce proteins for the cell.
Smooth - Transports proteins to the Golgi
Golgi Apperatus: Puts a tag of proteins to tell them what to do and sends them out to do their specific job
Ribosomes: make proteins from RNA that has copied the genetic code from the DNA in the nucleus.
Mitochondria: Powerhouse, Makes ATP which powers the cell and thus powers the entire organism.
Cell Membrane: Semipermeable, double lipid layer membrane protecting the cell as well as keeping good stuff in and bad stuff out.
Centrioles: Split apart the cell and help in the miotic process as well.
Lysosomes: Digests food and breaks down cell when it dies
Cytoplasm: the fluid inside a cell. Helps keep the shape of the cell. In constant motion to aid in organelle interaction.
Cytoskeleton: Holds the structure of the cell as well as protects the cell. Also it helps with intercellular transportation.
Proxisomes: break down toxins
1a) What might happen if there is a mutation in a gene that codes for the cytoskeleton protein that supports a muscle cell during contraction?
Depending on the mutation would change what would happen.
If the mutations makes the cytoskeleton of the muscle cell tougher, then when the cell is contracted it would be harder to break the cell. This could be beneficial and not helpful to someone. This sort of mutation would be helpful to someone when playing a sport so that it would be harder to tear or strain a muscle during competition. On the other hand it would be harder to get stronger when in a lifting program because the only way to grow more muscles is for your muscles to tear and then regrow stronger. If it is hard to tear those muscles it would be harder to get stronger.
It the mutation makes the cytoskeleton of a muscle cell weaker then it would be easier to tear muscles. Therefore, along the same context of the first situation, it would be easier to get stronger weightlifting but also easier to get injured in competition.
1b) Or a mutation in a gene that codes for a protein in the cell membrane that normally allows Chloride ions to pass through.
This mutation would mess up the cells ability to have chloride ions at work in the cell. Chloride ions are needed in the cell to regulate the fluids moving in and out of the cell. Therefore, if no chloride ions can pass through the cell then the cell would have all sorts of trouble regulating fluids and not have all the fluids and nutrients in the cell or have far too much.
1c) How do these DNA changes affect the function of the cell? Of the organism?
So, the defect is at the cellular/molecular level, but the functions of the cells contribute to the health of the overall organism.
2. When discussing cell function, how might the genes of a Paramecium differ from those of a frog? How might they be similar?
Well, they both have to do the basic work of the cell, or of any living thing – make energy out of food (metabolism), sense and respond to the environment, build cell structures, etc. So, they are similar in life’s basic requirements. But, a single-celled organism and a multi-celled organism have big differences in how they reproduce, move, find food, coordinate cellular activity/communication, etc. etc etc.
3. What does your breathing (oxygen in, carbon dioxide out) have to do with the function of a mitochondria? How might your body function differently if one of the genes that contribute to aerobic respiration doesn’t code for a functional enzyme?
The mitochondria needs oxygen to complete cellular respiration and make ATP (energy) for the cell. Without energy for the body you would not be able to do anything and eventually die.
a. Oxygen is required for ATP formation in mitochondria. Carbon dioxide is made in the process. So, you need to breathe in oxygen and out CO2 for mitochondria to make ATP from sugar.
b. A defect in an important enzyme will cause less ATP to be made. What are the ramifications of this during development? During adulthood?
4. What is the goal of cell cycle with mitosis vs. meiosis? How does the cell achieve its goal?
Mitosis: The goal of the cell cycle with mitosis is reproduction and growth. The goal is achieved because in the beginning there is one cell and then by the end there are two cells.
a. Mitosis – make new cells identical to the original
i. Every single chromosome needs to be copied and placed in daughter cell
Meiosis: The goal of meiosis is to great haploid cells with great genetic variation.
a. Meiosis – half the chromosome number. Randomly choose which of each chromosome pair to put in each sperm or egg.
i. Every chromosome needs to be copied. Two rounds of cell division. First round separates homologous
chromosome pairs – halves chromosome number, randomly assorts each homol pair into new cells, crossing
over creates additional shuffling of alleles. Round two separates sisters
5. What are sister chromatids? How do they differ from Homologous chromosomes?
Sister chromatids are genetically identical. Connected by a centromere during S phase.
Homologous chromosomes carry identical genes but have different alleles. One is from mom and one is from dad.
6. When and why does DNA need to replicate?
DNA needs to replicate in the S phase of interphase in order to split into two cells there needs to be two sets of DNA. (one for each)
6a) If one strand of a double-stranded DNA chromosome has the sequence:
?
7. How is a stem cell genetically (DNA sequence) different from other cells in your body? How is it otherwise different from other cells?
Stem cells are genetically identical to other cells in the body. They turn certain genes on and off in a particular order in order to
differentiate into specialized cell types. Specialized cells do specialized jobs because they express a particular collection of genes. Stem
cells have the ability to decide which of these collections to turn on. Specialized cells already have those genes on and can’t turn them off
or use a different collection.
8. What are the specific functional differences (what they can become) between embryonic stem cells, umbilical cord stem cells and adult stem cells?
Embryonic stem cells are totipotent
Umbilical cord stem cells are pluripotent
Adult stem cells are multipotent
An embryo can specialize into any cell type.
Umbilical cord stem cells in general can become any type of blood cell.
Adult stem cells can become only cell types that are present in the organ from which they come.
9. Cell division and apoptosis are normal parts of every individual's fetal development. For what reasons do we need cell death when we're mainly trying to make more cells to grow an individual? Why is it crucial to balance the mechanisms of cell division and apoptosis?
Cell death is important if major mistakes occur during DNA replication. In order to shape complex body structures, sometimes cells are
created as part of an overall structure and then some are killed to shape
10. What separates during Mitosis?
Nucleus
Sister Chromatids
11. What separates during Meiosis I? Meiosis II?
Meiosis I - Homologous Chromosomes
Meiosis II - Sister Chromatids
12. I start with a cell that has 23 pair (46 total) of chromosomes. The cell divides during Mitosis. How many pair of chromosomes do I have in each of the new “daughter” cells?
46
13. What is a gene? A gene is a segment of a chromosome that codes for a protein.
Picture link for gene below
http://www.google.com/imgres?q=gene&um=1&hl=en&sa=N&biw=1151&bih=718&tbm=isch&tbnid=AJg7DtkII6nANM:&imgrefurl=http://www.accessexcellence.org/AB/GG/genes.php&docid=6po6lD9qxgkobM&imgurl=http://www.accessexcellence.org/RC/VL/GG/images/genes.gif&w=450&h=415&ei=LRNlUOLxH4nEyQH0xoDYAg&zoom=1&iact=hc&vpx=636&vpy=77&dur=244&hovh=216&hovw=234&tx=119&ty=126&sig=115790456818182860432&page=1&tbnh=125&tbnw=135&&ndsp=16&ved=1t:429,r:3,s:0,i:161
What is an allele?
An allele is a version of a gene – it has a similar but slightly different sequence than other alleles and results in the production of a slightly different protein.
Picture link for allele below
http://1.bp.blogspot.com/-2-MwfZJPxp8/UD4tqJRqyBI/AAAAAAAABF4/4AweUu3BW1g/s1600/allele.jpg
14. If during Meiosis, the sister chromatids separated first, and then the homologous chromosomes, would it make a difference in the genetic diversity of the gametes?
There would be no crossing over making genetic diversity based solely on independent assortment limiting the possibilities of differences.
Multiple Choice
1. Which of the following stem cell types would be easiest use if you needed to treat liver disease?
a. umbilical cord stem cells. These are best for growing liver cells.
b. Embryonic stem cells. Since I can’t get any stem cells from my liver, I need to start over with the most powerful stem cells, embryonic.
c. Adult stem cells. Liver tissue has adult stem cells that could be stimulated to help repair liver damage.
d. Embryonic stem cells. These are the only stem cells that will really ever work.
2. A genetic mutation in a gene that influences ribosome function would cause a person to have which of the following problems?
a. Cancer
b. Vomiting
c. Reduced protein production
d. Fatigue
e. Memory loss
3. Cystic fibrosis is a disease cause by a faulty ion channel protein. To find a cure for this disease, why would geneticists be looking at a person’s genes if the real problem is a protein?
a. genes and proteins are the same thing, so it doesn’t matter which one you look at
b. genes hold the instructions for making protein, so genes are the cause of the protein problem.
c. genes fold up to become proteins, so looking at the genes is essential so figure out how the CF protein folds incorrectly
d. cystic fibrosis is a very complex disease involving the ion channel protein, as well as unrelated genes.
4. Some algae have 148 chromosomes total. At the end of Mitosis each new daughter cell contains ___ chromosomes.
a. 74
b. 37
c. 6
d. 148
e. 296
5. The genes my muscle cells contain are different than the genes my nerve cells contain.
a. True. Muscle cells and nerve cells need different genes to do different functions.
b. True. All cells in the body contain slightly different genes as a result of meiosis.
c. False. They both have the same genes, but muscle cells make different proteins than nerve cells do.
d. False. Nerve cells don’t even have a nucleus.
6. When your crazy professor tells you that you are very similar to an amoeba, what does she mean?
a. you have very little intellect
b. you move slowly, like a blob
c. chemically, you are similar, using the same molecules of life to make your cells
d. you eat paramecium for dinner
7. It is theoretically possible that an alternative mechanism for generating sex cells could have evolved (it didn’t, but it could have). If meiosis evolved in a cell such that S phase of interphase was skipped, which of the following would no longer be required? Why?
a. Meiosis I
b. Meiosis II b/c there would be no sister chromatids to split
8. During independent assortment, what is assorting independently in a cell performing meiosis I?
a. sister chromatids
b. homologous chromosomes
c. linked genes
d. centromeres
9. If during Meiosis, the sister chromatids separated first, and then the homologous chromosomes, would it make a difference in the genetic diversity of the gametes?
This is totally a hypothetical question so don’t stress J But we can speculate that if sister chromatids separate in Meiosis I you would have two identical cells, each with 24 pair of chromosomes. So, in each cell the homologous chromosomes could potentially pair and cross over before they separate in Meiosis II. In this case, all of the chromosomes in the original cell get to cross over, which might actually increase diversity over the way cells actually do it. Brain teaser. .
Nucleus: holds the genetic information, control center of the cell
ER: Rough - Covered by Ribosomes that produce proteins for the cell.
Smooth - Transports proteins to the Golgi
Golgi Apperatus: Puts a tag of proteins to tell them what to do and sends them out to do their specific job
Ribosomes: make proteins from RNA that has copied the genetic code from the DNA in the nucleus.
Mitochondria: Powerhouse, Makes ATP which powers the cell and thus powers the entire organism.
Cell Membrane: Semipermeable, double lipid layer membrane protecting the cell as well as keeping good stuff in and bad stuff out.
Centrioles: Split apart the cell and help in the miotic process as well.
Lysosomes: Digests food and breaks down cell when it dies
Cytoplasm: the fluid inside a cell. Helps keep the shape of the cell. In constant motion to aid in organelle interaction.
Cytoskeleton: Holds the structure of the cell as well as protects the cell. Also it helps with intercellular transportation.
Proxisomes: break down toxins
1a) What might happen if there is a mutation in a gene that codes for the cytoskeleton protein that supports a muscle cell during contraction?
Depending on the mutation would change what would happen.
If the mutations makes the cytoskeleton of the muscle cell tougher, then when the cell is contracted it would be harder to break the cell. This could be beneficial and not helpful to someone. This sort of mutation would be helpful to someone when playing a sport so that it would be harder to tear or strain a muscle during competition. On the other hand it would be harder to get stronger when in a lifting program because the only way to grow more muscles is for your muscles to tear and then regrow stronger. If it is hard to tear those muscles it would be harder to get stronger.
It the mutation makes the cytoskeleton of a muscle cell weaker then it would be easier to tear muscles. Therefore, along the same context of the first situation, it would be easier to get stronger weightlifting but also easier to get injured in competition.
1b) Or a mutation in a gene that codes for a protein in the cell membrane that normally allows Chloride ions to pass through.
This mutation would mess up the cells ability to have chloride ions at work in the cell. Chloride ions are needed in the cell to regulate the fluids moving in and out of the cell. Therefore, if no chloride ions can pass through the cell then the cell would have all sorts of trouble regulating fluids and not have all the fluids and nutrients in the cell or have far too much.
1c) How do these DNA changes affect the function of the cell? Of the organism?
So, the defect is at the cellular/molecular level, but the functions of the cells contribute to the health of the overall organism.
2. When discussing cell function, how might the genes of a Paramecium differ from those of a frog? How might they be similar?
Well, they both have to do the basic work of the cell, or of any living thing – make energy out of food (metabolism), sense and respond to the environment, build cell structures, etc. So, they are similar in life’s basic requirements. But, a single-celled organism and a multi-celled organism have big differences in how they reproduce, move, find food, coordinate cellular activity/communication, etc. etc etc.
3. What does your breathing (oxygen in, carbon dioxide out) have to do with the function of a mitochondria? How might your body function differently if one of the genes that contribute to aerobic respiration doesn’t code for a functional enzyme?
The mitochondria needs oxygen to complete cellular respiration and make ATP (energy) for the cell. Without energy for the body you would not be able to do anything and eventually die.
a. Oxygen is required for ATP formation in mitochondria. Carbon dioxide is made in the process. So, you need to breathe in oxygen and out CO2 for mitochondria to make ATP from sugar.
b. A defect in an important enzyme will cause less ATP to be made. What are the ramifications of this during development? During adulthood?
4. What is the goal of cell cycle with mitosis vs. meiosis? How does the cell achieve its goal?
Mitosis: The goal of the cell cycle with mitosis is reproduction and growth. The goal is achieved because in the beginning there is one cell and then by the end there are two cells.
a. Mitosis – make new cells identical to the original
i. Every single chromosome needs to be copied and placed in daughter cell
Meiosis: The goal of meiosis is to great haploid cells with great genetic variation.
a. Meiosis – half the chromosome number. Randomly choose which of each chromosome pair to put in each sperm or egg.
i. Every chromosome needs to be copied. Two rounds of cell division. First round separates homologous
chromosome pairs – halves chromosome number, randomly assorts each homol pair into new cells, crossing
over creates additional shuffling of alleles. Round two separates sisters
5. What are sister chromatids? How do they differ from Homologous chromosomes?
Sister chromatids are genetically identical. Connected by a centromere during S phase.
Homologous chromosomes carry identical genes but have different alleles. One is from mom and one is from dad.
6. When and why does DNA need to replicate?
DNA needs to replicate in the S phase of interphase in order to split into two cells there needs to be two sets of DNA. (one for each)
6a) If one strand of a double-stranded DNA chromosome has the sequence:
?
7. How is a stem cell genetically (DNA sequence) different from other cells in your body? How is it otherwise different from other cells?
Stem cells are genetically identical to other cells in the body. They turn certain genes on and off in a particular order in order to
differentiate into specialized cell types. Specialized cells do specialized jobs because they express a particular collection of genes. Stem
cells have the ability to decide which of these collections to turn on. Specialized cells already have those genes on and can’t turn them off
or use a different collection.
8. What are the specific functional differences (what they can become) between embryonic stem cells, umbilical cord stem cells and adult stem cells?
Embryonic stem cells are totipotent
Umbilical cord stem cells are pluripotent
Adult stem cells are multipotent
An embryo can specialize into any cell type.
Umbilical cord stem cells in general can become any type of blood cell.
Adult stem cells can become only cell types that are present in the organ from which they come.
9. Cell division and apoptosis are normal parts of every individual's fetal development. For what reasons do we need cell death when we're mainly trying to make more cells to grow an individual? Why is it crucial to balance the mechanisms of cell division and apoptosis?
Cell death is important if major mistakes occur during DNA replication. In order to shape complex body structures, sometimes cells are
created as part of an overall structure and then some are killed to shape
10. What separates during Mitosis?
Nucleus
Sister Chromatids
11. What separates during Meiosis I? Meiosis II?
Meiosis I - Homologous Chromosomes
Meiosis II - Sister Chromatids
12. I start with a cell that has 23 pair (46 total) of chromosomes. The cell divides during Mitosis. How many pair of chromosomes do I have in each of the new “daughter” cells?
46
13. What is a gene? A gene is a segment of a chromosome that codes for a protein.
Picture link for gene below
http://www.google.com/imgres?q=gene&um=1&hl=en&sa=N&biw=1151&bih=718&tbm=isch&tbnid=AJg7DtkII6nANM:&imgrefurl=http://www.accessexcellence.org/AB/GG/genes.php&docid=6po6lD9qxgkobM&imgurl=http://www.accessexcellence.org/RC/VL/GG/images/genes.gif&w=450&h=415&ei=LRNlUOLxH4nEyQH0xoDYAg&zoom=1&iact=hc&vpx=636&vpy=77&dur=244&hovh=216&hovw=234&tx=119&ty=126&sig=115790456818182860432&page=1&tbnh=125&tbnw=135&&ndsp=16&ved=1t:429,r:3,s:0,i:161
What is an allele?
An allele is a version of a gene – it has a similar but slightly different sequence than other alleles and results in the production of a slightly different protein.
Picture link for allele below
http://1.bp.blogspot.com/-2-MwfZJPxp8/UD4tqJRqyBI/AAAAAAAABF4/4AweUu3BW1g/s1600/allele.jpg
14. If during Meiosis, the sister chromatids separated first, and then the homologous chromosomes, would it make a difference in the genetic diversity of the gametes?
There would be no crossing over making genetic diversity based solely on independent assortment limiting the possibilities of differences.
Multiple Choice
1. Which of the following stem cell types would be easiest use if you needed to treat liver disease?
a. umbilical cord stem cells. These are best for growing liver cells.
b. Embryonic stem cells. Since I can’t get any stem cells from my liver, I need to start over with the most powerful stem cells, embryonic.
c. Adult stem cells. Liver tissue has adult stem cells that could be stimulated to help repair liver damage.
d. Embryonic stem cells. These are the only stem cells that will really ever work.
2. A genetic mutation in a gene that influences ribosome function would cause a person to have which of the following problems?
a. Cancer
b. Vomiting
c. Reduced protein production
d. Fatigue
e. Memory loss
3. Cystic fibrosis is a disease cause by a faulty ion channel protein. To find a cure for this disease, why would geneticists be looking at a person’s genes if the real problem is a protein?
a. genes and proteins are the same thing, so it doesn’t matter which one you look at
b. genes hold the instructions for making protein, so genes are the cause of the protein problem.
c. genes fold up to become proteins, so looking at the genes is essential so figure out how the CF protein folds incorrectly
d. cystic fibrosis is a very complex disease involving the ion channel protein, as well as unrelated genes.
4. Some algae have 148 chromosomes total. At the end of Mitosis each new daughter cell contains ___ chromosomes.
a. 74
b. 37
c. 6
d. 148
e. 296
5. The genes my muscle cells contain are different than the genes my nerve cells contain.
a. True. Muscle cells and nerve cells need different genes to do different functions.
b. True. All cells in the body contain slightly different genes as a result of meiosis.
c. False. They both have the same genes, but muscle cells make different proteins than nerve cells do.
d. False. Nerve cells don’t even have a nucleus.
6. When your crazy professor tells you that you are very similar to an amoeba, what does she mean?
a. you have very little intellect
b. you move slowly, like a blob
c. chemically, you are similar, using the same molecules of life to make your cells
d. you eat paramecium for dinner
7. It is theoretically possible that an alternative mechanism for generating sex cells could have evolved (it didn’t, but it could have). If meiosis evolved in a cell such that S phase of interphase was skipped, which of the following would no longer be required? Why?
a. Meiosis I
b. Meiosis II b/c there would be no sister chromatids to split
8. During independent assortment, what is assorting independently in a cell performing meiosis I?
a. sister chromatids
b. homologous chromosomes
c. linked genes
d. centromeres
9. If during Meiosis, the sister chromatids separated first, and then the homologous chromosomes, would it make a difference in the genetic diversity of the gametes?
This is totally a hypothetical question so don’t stress J But we can speculate that if sister chromatids separate in Meiosis I you would have two identical cells, each with 24 pair of chromosomes. So, in each cell the homologous chromosomes could potentially pair and cross over before they separate in Meiosis II. In this case, all of the chromosomes in the original cell get to cross over, which might actually increase diversity over the way cells actually do it. Brain teaser. .