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96 Cards in this Set
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- Back
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Two brown-haired, brown-eyed parents can't have a child with blonde hair and blue eyes. The child must have been adopted. True or False.
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True.... Actually it is possible.
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What did Lamarkian biologists believe?
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They thought characteristics like the height, strength, and weight of an offspring were determined by the activities of the parents. For instance, if parents spent a lot of time in strenuous activity, their children would be born stronger. Somehow, they thought that the parents' activities would send “messages” to their reproductive systems, telling them what kind of offspring to produce.
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Who is Gregor Mendel, what was he credited for, and why did it take so long for his work to be known?
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The beginning of a real explanation for how traits are passed on from generation to generation was developed by a monk name Gregor Mendel in the mid 1800s. He did careful experiments with peas, determining how pea plants reproduced and passed on characteristics to their offspring. Unfortunately, this magnificent work was tucked away in a monastery for more than 50 years! When it was finally discovered, it laid the groundwork for all of our modern studies of genetics.
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How does DNA determine your eye color?
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Your eye color is completely dependent upon what proteins are produced in some of the cells in your eyes. Thus, by coding for the production of certain proteins in your eyes, your DNA determines your eye color.
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There is some inherent limit set up by your DNA that makes it so that you are limited to how strong you can become. True or False?
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True. A person might lift weights and work out every day but never become as strong as another individual who really does not exercise seriously at all. In the case of muscle strength, your DNA determines a general range of how strong your muscles can become.
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There are three factors in determining the characteristics of a person. What are they?
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genetic factors,
environmental factors, and spiritual factors. (spiritual factors only apply to humans) |
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DNA alone does not determine who you are or what you will become. There are some traits (blood type, for example) that are completely determined by your DNA. DNA just sets up a general framework. True or False?
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True.
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Two identical twins have exactly the same set of genes. They are separated at birth and grow up in different households. If a scientist were to study the twins as adults, would he find them to be identical in every way, since they have the same genes? Why or why not?
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No, they will not be identical in every way. Because they have the same genes, they will have the same genetic tendencies and traits. Any characteristic that is determined completely by genetics will be the same in each twin. However, any characteristics in which environmental and spiritual factors play a role (weight, personality, strength, etc.) will most likely be at least somewhat different in each, since they grew up in different environments.
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How do cells perform such radically different tasks like skin cells versus retina cells?
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The answer is simple: they produce different types of proteins.
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Like DNA, RNA is also made up of nucleotides, but the individual structure of the nucleotides is a bit different. How is it different?
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1. First of all, the sugar that makes up the foundation of the nucleotides is ribose, not deoxyribose (as is the case with DNA).
2. Unlike DNA, the RNA nucleotides do not form a double helix. Instead, RNA is usually a single strand of joined nucleotides. 3. Like DNA, RNA has four nucleotide bases. While three of them are the same as DNA's (adenine, cytosine, and guanine), one of them is different (uracil). RNA has uracil in place of thymine. |
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Why is DNA more chemically stable than RNA? Why is that important in terms of genetics?
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DNA is much more chemically stable than RNA because DNA uses thymine and deoxyribose instead of uracil and ribose.
This means it is unlikely to undergo major changes with time, making it the ideal molecule for storing information from generation to generation, so that each organism reproduces after its kind. |
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Why are the differences in RNA important in the process of how the cell makes proteins?
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The main portion of a cell's DNA is in its nucleus, but proteins are made in the ribosomes, which are outside the nucleus. In order to get information from the nuclear DNA to the ribosomes, one type of RNA makes a “snapshot” of the DNA and takes that information out of the nucleus to the ribosome.
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How does RNA act like a camera???
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When RNA does its job, it produces a “negative” of the DNA section that it is copying. Everywhere the DNA has a cytosine, the RNA will have a guanine. Everywhere the DNA has a guanine, the RNA will have a cytosine. Everywhere that DNA has a thymine, the RNA will have an adenine, and everywhere DNA has an adenine, the RNA will have a uracil. This is much like what happens when film is developed. During the developing process, the first thing to appear is a negative. This negative is dark everywhere that the picture is supposed to be light, and it is light everywhere that the picture is supposed to be dark. Based on this negative, then, a picture can be made. Based on the “negative” produced by RNA, a protein can be made.
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Why would DNA "unwind" a section of the double helix?
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When it is time for the cell to manufacture a protein, DNA "unwinds the section of the double helix that codes for the production of that protein.
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After the DNA "unwinds" the section of the double helix that codes for the production of a certain protein, what happens then?
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Individual RNA nucleotides begin bonding to the exposed DNA nucleotides.
They bond with their partners: cytosine with guanine and urasil with adenine. This builds a strand of RNA. |
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An RNA strand has the following sequence of nucleotides:
uracil, adenine, adenine, guanine, cytosine, cytosine What was the nucleotide sequence in the DNA that it transcribed? |
Guanine can bond to cytosine and vice-versa. Thus, when the RNA has guanine, the DNA must have had cytosine. When the RNA has cytosine, the DNA must have had guanine. Adenine bonds with uracil and vice-versa. Thus, when you see a uracil in RNA, there must have been an adenine in the DNA. Now, when you see an adenine in RNA, you might think that there was a uracil in the DNA. However, DNA has no uracil. It has thymine instead. Thus, when you see an adenine in RNA, there was a thymine in DNA. Therefore, the DNA sequence must have been:
adenine, thymine, thymine, cytosine, guanine, guanine |
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A DNA strand has the following sequence of nucleotides:
thymine, thymine, thymine, adenine, guanine, cytosine What will the RNA sequence be when this DNA section is transcribed? |
The same rules apply here, realizing that RNA has uracil. Thus, when DNA has cytosine, RNA will have guanine. When DNA has guanine, RNA will have cytosine. When DNA has thymine, RNA will have adenine. When DNA has adenine, RNA will have uracil.
adenine, adenine, adenine, uracil, cytosine, guanine |
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What happens to the RNA after transcription?
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After transcription, the RNA leaves the nucleus and moves to the ribosome.
This carries the negative image of the gene that was transcribed to the organelle that produces the protein. |
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Why is it called "messenger RNA?"
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Because the RNA that performs transcription is essentially a messenger (sending instructions from the nuclear DNA to the ribosome.)
Remember, that in order to get the DNA's instructions from the nucleus to the ribosome, RNA produces a negative image of the DNA's nucleotide sequence and takes it to the ribosome. |
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In addition to this anticodon, tRNA is bonded to .... what?
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an amino acid
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The amino acid bonded to the tRNA is determined by the three nucleotide bases in the anticodon. Explain this by giving examples...
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For example, when the anticodon is made up of uracil, uracil, and cytosine (in that order), the tRNA is bonded to the amino acid lysine. If, instead, the anticodon is made up of uracil, cytosine, and cytosine, the tRNA is bonded to the amino acid arginine. This bond means that everywhere the tRNA goes, the amino acid goes as well.
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When an mRNA molecule comes to the ribosome, the tRNA strands are attracted to the three nucleotide bases that will bond with the three nucleotide bases in their anticodon. What does this mean? Give examples of which bonds with which...
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If a tRNA strand has guanine, cytosine, and adenine, it will be attracted to a section of the mRNA that has cytosine, guanine, and uracil in succession. If such a sequence exists, the tRNA will go and link up with it, carrying the amino acid to which it is bonded the whole way.
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Okay, here is a new form of question in flashcard form...
Fill in the blanks!!! :o) A strand of ______ can be thought of as a bunch of three-nucleotide sequences. Each three-nucleotide base sequence is called a ______. A strand of ________ contains a three-nucleotide base sequence called an ________ . A certain _______ on _______ results in a certain amino acid bonded to the ______ . Since the _______ _______ are attracted by the mRNA codons, the net result is that a codon on mRNA attracts a specific amino acid. Hint: vocab terms are used more than once. |
1. mRNA
2. codon 3. tRNA 4. anticodon 5. anticodon 6. tRNA 7. tRNA 8. tRNA 9. anticodons |
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What is a protein?
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It is a bunch of amino acids linked together in a particular sequence. This happens again and again and again, so that many, many amino acids link up together. When all the amino acids called for by the codons on mRNA are linked together, the result is a protein!
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What happens in transcription?
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In transcription, mRNA makes its negative image in order to copy the nucleotide sequence in DNA. This is much like a transcriptionist “copying” a conversation by writing everything down.
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What happens during translation?
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The mRNA leaves the nucleus and goes to the ribosome, where tRNA strands carry amino acids to the mRNA and line them up in the order determined by the sequence of nucleotides. The amino acids then bond together, making a protein. This step is called translation because the “language” of nucleotide base sequences in RNA is translated into the “language” of amino acid sequences in a protein.
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What are the main steps in protein synthesis in cells?
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1. In the nucleus of the cell, DNA unwinds.
2. RNA nucleotides in the nucleus bond with the DNA nucleotides, forming a strand of RNA. 3. The mRNA then leaves the nucleus through a nuclear pore and goes to a ribosome, where there are plenty of tRNA molecules and the associated amino acids. 4. In the ribosome, tRNA strands are attracted to mRNA sections that have a codon with which their anticodon can bond. They bond to that section of the mRNA, dragging their amino acids with them. This results in amino acids sitting next to each other. The amino acids bond, and after this happens many, many times.... a protein if formed. |
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True or False? A single codon cannot call for more than one amino acid, but a single amino acid can have many codons that call for it.
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True. A given amino acid can be called for by several different codons. For example, the amino acid cysteine can be called for by a sequence of uracil, guanine, and cytosine or by a sequence of uracil, guanine, and uracil.
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In order for the ribosome to have the proper instructions, the mRNA must be “processed” before it gets to the ribosome. What happens to the introns during this processing?
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During this “processing,” the introns are removed and the exons are spliced together, so that by the time it gets to the ribosome, the mRNA has the information necessary to make the protein (the exons) and nothing more (no introns).
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A scientist is studying a nucleic acid, but her notes are sketchy. You do not know whether she is studying DNA or RNA. You can make out the following nucleotide sequence, however:
guanine, cytosine, cytosine, uracil, guanine, adenine Is the scientist studying DNA or RNA? |
The scientist must be studying RNA, because only RNA has uracil.
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A protein has alanine as its first amino acid. One codon that calls for alanine has the following sequence of nucleotide bases:
guanine, cytosine, adenine a. If a portion of DNA instructs a cell to make this protein, what will be the first three nucleotide bases of that DNA portion? |
a. Now remember, if this is a codon, then it must be on the mRNA. Thus, the sequence given is the sequence made by mRNA during transcription. The DNA, then, must have the complement of this sequence. We can therefore use the same reasoning that we did in question 7.2. Thus, the DNA must have had:
cytosine, guanine, thymine |
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A protein has alanine as its first amino acid. One codon that calls for alanine has the following sequence of nucleotide bases:
guanine, cytosine, adenine b. What will be the sequence of nucleotide bases on the tRNA that responds to the mRNA codon given above? |
b. The tRNA must also have the complement to this sequence. Unlike DNA, however, RNA uses uracil rather than thymine. Thus, the tRNA must have:
cytosine, guanine, uracil |
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Now as you might expect, it takes a lot of DNA to carry all of the genes necessary to code for the proteins of a living organism. Thus, there are several different chromosomes in the nucleus of the cell. What you might not expect, however, is that the number of chromosomes is dependent on the organism studied. The more complex organisms have more chromosomes than less complex organisms.
Is this entire paragraph true or false? |
It is false. The first part is true, but the part about how more complex organisms have more chromosomes than less complex organisms is utterly false!!!! (If it were true, it would mean crayfish were more complex than humans!)
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Why is mitosis also called "cellular division?"
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Asexual reproduction results in offspring that have exactly the same genetic code as that of the parent. Since this is the case, we often call mitosis “cellular division,” because, in the end, the process makes two duplicate cells from a single cell.
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When it is time to for the cell to asexually reproduce, two things happen. What are they?
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1. First, the chromosomes must duplicate by making copies of themselves.
2. The centrioles, which are outside the nucleus, duplicate themselves so that there are two sets of centrioles. |
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When the sister chromatids join together at the centromere, they form a certain shape . This is the common representation of a chromosome. What is the shape they form?
(chromosomes only look like this because they have been duplicated) |
an “X” shape
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The condensed form of an unduplicated chromosome is what type of shape?
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the dumbbell shape
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What happens at the conclusion of metaphase?
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At the conclusion of metaphase, the microtubules on the spindle pull the chromosomes towards the centrioles. Since each of the sister chromatids has a microtubule pulling on it from opposite centrioles, the sister chromatids separate from one another. One gets pulled to one side of the cell, and the other gets pulled to the opposite side of the cell.
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Explain what happens during telophase.
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During this time, the spindle begins to disintegrate, and the plasma membrane begins to constrict along the equatorial plane, eventually forming two cells where there was once only one. A nuclear membrane begins to form around each group of chromosomes, and the chromosomes uncoil from their condensed form, forming the chromatin material of the nucleus. At this point, there are two daughter cells where there was just one mother cell before.
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the division of organelles between the two daughter cells is regulated during the process of mitosis. Each daughter gets at least one of each organelle. If there was only one of a given organelle prior to mitosis, it is divided between the two daughters.
Explain why getting only half of the organelles or even part of them isn't a problem. |
the DNA in each of the cells has all of the information necessary to construct any organelles that the cell needs. Thus, the cells can build more of each organelle, and they can also complete any partial organelles that they have. In fact, since mitochondria have their own DNA, they can actually replicate themselves. As a result, if there is only one mitochondrion in a cell during interphase, it can actually replicate during mitosis so that each daughter gets one.
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How does mitosis relate to human cells?
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When you grow from a baby to an adult, your cells go through mitosis. Even after you are fully grown, your cells must continually go through mitosis in order to replace cells that have died. For example, millions of red blood cells die every minute in your body. If they weren't replaced, you would soon run out of them. How are they replaced? By mitosis, of course.
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The major difference between plant and animal mitosis is found in telophase. What is that difference?
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Because of the rigid cell wall in a plant cell, the plasma membrane cannot just constrict as we learned in animal cell mitosis. Instead, once the chromosomes have been pulled to the centrioles, vesicles containing the building blocks for the plasma membrane line up along the equatorial plane. These vesicles begin fusing together, forming a new plasma membrane. As the new plasma membrane forms, cellulose is formed in the middle, forming a new cell wall that splits the plasma membrane in two. Eventually, even a middle lamella is formed, resulting in two cell walls, two plasma membranes, and thus, two cells
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The phases of a cell's life are listed below. Which one is not a part of mitosis? Take the remaining phases and order them according to when they occur in the mitosis process.
anaphase, prophase, interphase, telophase, metaphase |
Interphase is not a part of mitosis. This phase of a cell's life is defined as the time between reproduction cycles. The remaining phases occur in the following order: prophase, metaphase, anaphase, telophase.
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A cell uses vesicles to build the plasma membrane during the telophase of mitosis. Is it a plant cell or an animal cell?
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It must be a plant cell. In animal cells, the two new cells are created when the plasma membrane constricts. This can't happen in a plant cell because of the rigid cell wall. Thus, plant cells use vesicles to carry the components of the plasma membrane and cell wall between the two nuclei and build them there.
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In which phase of mitosis are the chromosomes separated from their duplicates?
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Chromosomes are separated from their duplicates during anaphase.
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How many chromosomes do humans have?
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In a human cell, there are 23 chromosome pairs, for a total of 46 chromosomes. The two members of a chromosome pair are very similar, but they are not identical.
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If you compare the 23 chromosomes from a female against the 23 chromosomes from a male.... how can you tell which ones belong to the male?
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If a cell has similar chromosomes in its 23rd pair, the cell must be from a female. If not, it must be from a male.
The female will have two X shaped, and the male will have one X and one Y shaped. |
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What is the diploid number (2n) of a human cell?
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46
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What is the haploid number (n) of a human cell?
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23
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A haploid cell has only one chromosome from each pair. Thus, the haploid number is also the number of chromosomes in a haploid cell.
Is that true or false? |
true
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A pea plant has seven pairs of homologous chromosomes. What is its haploid number? What is its diploid number?
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The haploid number is the number of homologous pairs. Thus, the haploid number is seven. The diploid number is the total number of chromosomes in the nucleus. Since there are seven pairs and each pair has two, there are a total of 14 chromosomes in the nucleus. The diploid number, therefore, is 14.
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In a scientist's notebook, you find notes regarding a new species that is being studied. The notes say that the species is diploid, with a chromosome number of 17. Is this the haploid or diploid number? If this is the haploid number, give the diploid number. If this is the diploid number, give the corresponding haploid number.
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Since the number is odd, it cannot be a diploid number. Remember, diploid cells have chromosomes that come in pairs. Since there are two chromosomes in a pair, then the total number of chromosomes (the diploid number) will always be even. By virtue of the fact that this is an odd number, then, we know that it is a haploid number. Since the haploid number is 17, the diploid number will be twice that. Thus, the diploid number is 34.
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If a human has 46 chromosomes and each parent contributes to the DNA of the offspring, then how many chromosomes can each parent contribute?
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23
If the parents each contributed more than 23 chromosomes, the offspring would have more than 46 chromosomes. |
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the process of meiosis is split into two groups of phases, meiosis I and meiosis II. What phases are in each of these parts of meiosis?
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Each of these parts of meiosis involves prophase, metaphase, anaphase, and telophase.
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Which phase is the first step in what differentiates meiosis from mitosis? Explain how the two differ.....
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metaphase I
In mitosis, the microtubules attach so as to pull the chromosomes away from their duplicates. In meiosis, however, the microtubules attach so as to pull the homologous pairs apart while leaving the chromosomes attached to their duplicates. |
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Explain how in anaphase I the process is different between meiosis and mitosis.
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In the anaphase of mitosis, each chromosome is separated from its duplicate. Thus, the “X”-shape goes away, because the chromosome goes one way and its duplicate goes the other. Both chromosome homologues go one way while both duplicate homologues go the other. In anaphase I of meiosis, however, the chromosomes stay with their duplicates. Instead, the homologues are separated from one another, breaking up the homologous pairs.
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Summarize the three main differences between meiosis and mitosis.
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1. Mitosis takes one cell and makes an exact duplicate, resulting in two cells. If the original cell is diploid, the copy will be diploid as well. In contrast, meiosis takes a single cell and produces four cells. The cells produced are quite different from the original. The original is diploid, but the four cells produced are haploid. These haploid cells are called gametes.
2. meiosis has twice as many steps as mitosis 3. While the anaphase of mitosis keeps the homologous pairs of chromosomes together and separates the chromosomes from their duplicates, anaphase I of meiosis separates the homologous pairs, keeping the chromosomes and their duplicates together |
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True or False?
Two sister chromatids that form the “X” shape during mitosis and meiosis count as only one chromosome. Explain your answer. |
The two cells at the end of meiosis I have two chromosomes each. Both of those chromosomes are duplicated, but the chromosome and its duplicate count as only one chromosome, because they each carry exactly the same information. Since the duplicate adds no new information to the nuclear DNA, it does not count as a second chromosome.
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Although meiosis occurs in both the female and the male of an animal species, there are differences between the two. As mentioned before, in males, the gametes produced by meiosis are called sperm, while in females, the gametes are called eggs. It turns out that these gametes are quite different. As a result, the process of meiosis II is different in males and females.
Explain the differences and in which phase it occurs. |
1. Males ~ In male animals, once telophase II ends, the gametes produced grow flagella. This is accomplished by a centriole, which moves to the plasma membrane and grows a microtubule through the membrane and out into the surroundings. The sperm can then use these flagella to move about in search of an egg.
2. Females ~ At the end of telophase I, one of the two cells that are produced takes most of the cytoplasm as well as most of the organelles. Thus, this cell is much bigger than the other. Both cells go through meiosis II. However, since the small cell is so small, the two gametes it produces are quite small. In addition, when the big cell reaches telophase II, one of the two gametes once again takes most of the cytoplasm and organelles. As a result, meiosis II ends up producing three tiny gametes and one large gamete. |
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What are the differences between polar bodies and eggs?
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The three tiny gametes produced in meiosis II, often called polar bodies, are useless. If they are fertilized, the resulting zygote will quickly degenerate and die. Only the large gamete, called the egg, can produce a viable zygote through fertilization.
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Which phases of meiosis are essentially the same as the corresponding phases of mitosis? Which are different?
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Since meiosis II is essentially mitosis that occurs on two cells, the stages of meiosis II are all essentially the same as mitosis. Thus, prophase II, metaphase II, anaphase II, and telophase II are essentially the same as the corresponding stages of mitosis. In addition, prophase I is essentially the same as the prophase of mitosis.
Metaphase I is different from the metaphase of mitosis, because the microtubules attach so as to separate homologues in metaphase II. In the metaphase of mitosis, the microtubules attach so as to pull the chromosome duplicates apart from their originals. Anaphase I is also different from the anaphase of mitosis, because in anaphase I the homologues get pulled apart, whereas in the anaphase of mitosis, the chromosome duplicates get separated from their originals. Finally, telophase I is different from the telophase of mitosis because the former results in haploid cells while the latter results in diploid cells. |
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A cellular reproduction process results in four diploid cells. Is this mitosis or meiosis? How many cells underwent this process
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This must be mitosis. Meiosis always results in haploid cells. Since mitosis makes two cells for every one that goes through the process, two cells must have gone through mitosis to produce four cells in the end.
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A cellular reproduction process results in four haploid cells. Is this mitosis or meiosis? How many cells underwent this process?
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This was meiosis. Mitosis results in diploid cells. Since meiosis forms four cells for every one that undergoes the process, one cell must have undergone meiosis to get four cells in the end.
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A sperm cell finds a polar body and attempts to fuse with it. Will a viable zygote develop?
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A viable zygote will not develop. Polar bodies are so small that they cannot function properly.
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Do viruses have DNA as their genetic material, or do they have RNA as their genetic material?
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Some have RNA as their genetic material, and others have DNA.
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Explain how viruses infect their hosts.
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Since viruses cannot reproduce themselves, they rely on cells to do it for them. In order to do this, a virus will attach itself to a cell. The virus either enters the cell or injects its genetic material into the cell. The genetic material of the virus redirects the cell's reproductive machinery to reproduce the DNA or RNA of the virus, as well as the proteins that make up the virus. The cell's biosynthetic machinery is then directed to assemble these pieces into new viruses. This continues until there are so many viruses that the cell ruptures, destroying the cell and releasing new viruses to infect other cells.
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HIV, the virus that causes AIDS (acquired immune deficiency syndrome) doesn't cause sickness right away. Why not?
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Some viruses can inject their genetic material into a cell so that it lies dormant for as long as several years before beginning the lytic pathway. Thus, the time between a host receiving the virus and manifesting the symptoms of the malady caused by that virus can be several years.
Such is the case with HIV and AIDS. |
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True or false? Humans aren't the only ones affected by viruses. Plants and even bacteria can be infected as well.....
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True.
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All phagocytic cells move to where they need to fight the virus. True or False?
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False. Some move, but others... like those in the lymph nodes... remain stationary.
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What happens after you are given a vaccine?
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When you are given a vaccine, a weakened or inactive version of the virus is injected into your body. This virus has been changed so that it cannot enter the lytic pathway very effectively. As a result, your body has plenty of time to figure out what antibodies to make in order to destroy it. Once your body produces the antibodies, it produces cells that remember how to do it. That way, when you are exposed to the real virus of the same type, those cells help the body produce the antibodies specific to the virus right away. This reduces the number of viruses that can enter the lytic pathway, making you less likely to get the disease that the virus causes.
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Why must vaccines be given before you get infected by the virus?
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Vaccines act like a wall of defense. If you do not build the wall before the attackers come, you will be too late.
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True or False? In order to protect you, a vaccine must have some of the virus in it.... whether it be dead or just weakend.
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False. some vaccines don't even contain a virus at all. For some viruses, medical scientists have been able to construct a chemical “mimic” that the body thinks is a virus. This kind of vaccine is ideal, of course, because it doesn't contain a pathogen at all.
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How is a new vaccine tested before it is given to the general public?
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Before a vaccine is approved for use in the United States, it must go through many tests on animals, and then it must go through three separate phases of testing on people. In each phase, the people that volunteer for the test are closely monitored for health problems. If the rate of health problems in the testing group is higher than that of those not getting the vaccine, the vaccine is not allowed to be used on the general public. By the end of this three-phase testing process, the vaccine has been tested on thousands of volunteers over a period of several years. If the vaccine were not safe for the vast majority of people, this three-phase testing system would demonstrate that, and the vaccine would not be approved for general use.
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What is the principal difference between viruses and pathogenic bacteria?
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A pathogenic bacterium is alive; a virus is not.
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The human body can produce the antibodies that destroy smallpox. If this is the case, why did so many people die from it? Why didn't their bodies just kill the virus?
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Even though the body can produce the antibodies, it cannot do so quickly enough to destroy the virus before many viruses reach the lytic pathway. As a result, the virus is reproduced so quickly that it overwhelms the body. The smallpox vaccine defended so well against the virus, however, that the smallpox virus has been wiped out. It now only exists in laboratories and, as a result, this vaccine is no longer necessary!
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A DNA strand has the following sequence of nucleotides:
guanine, cytosine, adenine, adenine, thymine, guanine a. What will the mRNA sequence be? b. How many amino acids will the mRNA code for? c. How many codons will the mRNA have? d. What are the anticodons on the tRNAs that will bond to the mRNA? |
Guanine and cytosine can bond together, as can adenine and thymine. In RNA, however, uracil
replaces thymine. Thus when DNA has an adenine, RNA will have a uracil. When DNA has a thymine, RNA will have an adenine. When DNA has a cytosine, RNA will have a guanine, and when DNA has a guanine, RNA will have a cytosine. This makes the mRNA sequence: a. cytosine, guanine, uracil, uracil, adenine, cytosine b. It takes three nucleotide bases to code for an amino acid. Since this has six, it will code for two amino acids. c. Each codon codes for one amino acid. Thus, there are two codons on the mRNA. d. When mRNA has an adenine, tRNA will have a uracil. When mRNA has a uracil, tRNA will have an adenine. When mRNA has a cytosine, tRNA will have a guanine, and when mRNA has a guanine, rRNA will have a cytosine. This makes the rRNA anticodons sequences: guanine, cytosine, adenine and adenine, uracil, guanine |
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DNA ----->RNA----->Protein
Fill in the blanks (arrows) with the words that describes what is happening. First blank = a and the second blank = b. |
a. transcription
b. translation |
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An RNA strand has an anticodon. Is it tRNA or mRNA?
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This is tRNA, because only tRNA has anticodons.
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Protein synthesis is occurring in a ribosome. Is this a part of transcription or translation?
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If it is occurring in the ribosome, the proteins is actually being assembled. This is translation
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Suppose scientists determine that a set of genes is significantly more prevalent in murderers than in
the population at large. Would that mean that murderers are not at fault for what they do? Why or why not? |
This would not mean that murders have no fault for what they do. Most genes only establish
genetic trends. Environmental and spiritual factors affect the extent to which you follow those trends. Even if you have a genetic tendency to murder, the choices that you make can keep you from following that tendency |
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If you look under a microscope and see distinct chromosomes in a cell, is the cell in interphase?
Why or why not? |
It is not in interphase. Chromosomes only pack into their condensed form during reproduction
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List (in order) the four stages of mitosis.
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Prophase,
metaphase, anaphase, telophase |
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The diploid number of a cell is 16. What is its haploid number?
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Diploid number is the total number of chromosomes in the cell. Haploid number is the number of
homologous pairs. If there are a total of 16 chromosomes, then there must be 8 pairs. The haploid number is 8. |
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The haploid number of a cell is 9. What is its diploid number?
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Since haploid number is the number of pairs, that tells us there are nine pairs. The diploid numbers
is the total number of chromosomes in a diploid cell, which has both members of each pair. Since there are nine pairs, the diploid number is 9x2, or 18. |
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What is the difference between a gamete and a regular animal cell?
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A gamete is haploid while a regular animal cell is diploid. This means that a gamete has only one
chromosome from each homologous pair. A regular cell always both members of each homologous pair. |
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List (in order) all of the stages of meiosis.
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prophase I, metaphase I, anaphase I, telophase I, prophase II,
metaphase II, anaphase II, telophase II. |
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Which is closer to mitosis: meiosis I or meiosis II?
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Meiosis II: It is essentially mitosis acting on two haploid cells.
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A single cell with seven pairs of homologous chromosomes goes through meiosis I. How many
cells result at the end of meiosis I? How many chromosomes exist in each cell? Are the chromosomes in each cell duplicated or not? |
In meiosis I, a single diploid cell splits into two haploid cells with duplicated chromosomes. Thus,
there are two cells. Since they are haploid, they have one chromosome from each pair. Since there are seven pairs, each cell has seven chromosomes. The chromosomes are duplicated, because the purpose of meiosis II is to separate the duplicates from the originals. |
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. Four cells that originally (prior to meiosis I) had seven pairs of homologous chromosomes go
through meiosis II. How many cells result? How many (total) chromosomes exist in each cell? Are the chromosomes in each cell duplicated or not? |
Before any meiosis started, these cells had seven pairs of chromosomes. When they went through
meiosis I, they became haploid, so they now have seven chromosomes in total. The chromosomes are duplicated. In meiosis II, the duplicate chromosomes are separated from the originals, producing haploid cells with no duplicated chromosomes. Since there are four cells going through meiosis II, there are eight cells produced, there are seven chromosomes in each, but the chromosomes are not duplicated. |
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What are gametes produced in male animals called? What are gametes produced in female
animals called? |
Male gametes are called sperm, while female gametes are called eggs.
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How many useful gametes are produced in the meiosis of male animals? What about female
animals? |
Male animals produce four useful gametes with each meiosis, while female animals produce only
one. |
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What is the difference between a polar body and an egg?
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. A polar body is a non-functional female gamete, because it is far too small to function properly.
An egg is the one female gamete produced by meiosis that is large enough to function properly. |
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Which gamete can move on its own: the male gamete or the female gamete?
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Sperm have flagella; thus, the male gamete can move on its own.
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What is the purpose of the lytic pathway?
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The lytic pathway is the way in which viruses reproduce, killing the cells of its host.
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If a virus uses DNA as its genetic material, is it alive? Why or why not?
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No virus is alive, because a virus cannot reproduce on its own.
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A person decides to wait until he contracts measles before getting the vaccine. What is wrong
with this strategy? |
A vaccine is only good if you take it before getting infected, because it is meant to build up the
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