chapter 13 meiosis & sexual life cycles
Overview
This chapter includes information on a type of cellular division. Mitosis!? Nope, meiosis. Meiosis is the division of germ cells into four haploid (n) gametes, which can go on to form zygotes in sexual reproduction. This process differs from mitosis in more ways than one. Beyond some obvious distinctions concerning the purpose of each kind of cellular division, meiosis also results in genetic variation and includes two stages, meiosis I and meiosis II. During the first round of division crossing over occurs, in which two duplicated chromosome pairs exchange gene segments. In this way, meiosis produces genetic variation and offspring can inherit unique genes from their parents. Also, meiosis reduces the number of chromosome sets from diploid in the 'parent' cell to haploid in the daughter cells. As a result, the sex cells will combine to form a diploid organism after fertilization.
A section of this chapter also mentions the alternation of generations that occurs in the sexual life cycles of some plants (and algae). The gametophyte generation consists of a multicellular haploid stage in which mitosis takes place, which eventually gives rise to the sporophyte generation, a multicellular diploid stage, which eventually gives rise again to the gametophyte generation in a continuous cycle.
Big Ideas
3.A.2 In eukaryotes, heritable information is passed to the next generation via processes that include the cell cycle and mitosis, or meiosis plus fertilization.
3.C.2 Biological systems have multiple processes that increase genetic variation.
Artifact
Click HERE to view the lab report on mitosis and meiosis.
Reflection
This laboratory experiment proved to be extremely helpful while studying mitosis and meiosis. Viewing the slide of plant cells in various stages of mitosis allowed students to get an idea of what the process looks like in reality. Also, due to the fact that the amount of cells in each stage of division had to be counted, we could learn what stages took the most versus the least time to complete. Also, the pre-lab and post-lab questions encouraged me to think about specific details of cell division, but more importantly, about what could go wrong as well. If chromosomes do not separate correctly during meiosis, then an incorrect and often detrimental amount of chromosomes may develop in offspring. Not to mention the often devastating effects of uncontrolled division, namely cancer, as mentioned in Chapter 12.
This chapter includes information on a type of cellular division. Mitosis!? Nope, meiosis. Meiosis is the division of germ cells into four haploid (n) gametes, which can go on to form zygotes in sexual reproduction. This process differs from mitosis in more ways than one. Beyond some obvious distinctions concerning the purpose of each kind of cellular division, meiosis also results in genetic variation and includes two stages, meiosis I and meiosis II. During the first round of division crossing over occurs, in which two duplicated chromosome pairs exchange gene segments. In this way, meiosis produces genetic variation and offspring can inherit unique genes from their parents. Also, meiosis reduces the number of chromosome sets from diploid in the 'parent' cell to haploid in the daughter cells. As a result, the sex cells will combine to form a diploid organism after fertilization.
A section of this chapter also mentions the alternation of generations that occurs in the sexual life cycles of some plants (and algae). The gametophyte generation consists of a multicellular haploid stage in which mitosis takes place, which eventually gives rise to the sporophyte generation, a multicellular diploid stage, which eventually gives rise again to the gametophyte generation in a continuous cycle.
Big Ideas
3.A.2 In eukaryotes, heritable information is passed to the next generation via processes that include the cell cycle and mitosis, or meiosis plus fertilization.
3.C.2 Biological systems have multiple processes that increase genetic variation.
Artifact
Click HERE to view the lab report on mitosis and meiosis.
Reflection
This laboratory experiment proved to be extremely helpful while studying mitosis and meiosis. Viewing the slide of plant cells in various stages of mitosis allowed students to get an idea of what the process looks like in reality. Also, due to the fact that the amount of cells in each stage of division had to be counted, we could learn what stages took the most versus the least time to complete. Also, the pre-lab and post-lab questions encouraged me to think about specific details of cell division, but more importantly, about what could go wrong as well. If chromosomes do not separate correctly during meiosis, then an incorrect and often detrimental amount of chromosomes may develop in offspring. Not to mention the often devastating effects of uncontrolled division, namely cancer, as mentioned in Chapter 12.
chapter 14 Mendel & the gene idea
Overview
The chapter on "simple" Mendelian genetics does not usually turn out to be as simple as expected. However, the experiments that Gregor Mendel performed and the laws he discovered are pivotal to the history of genetics in biology and engaging to learn about.
This famous scientist identified two laws of inheritance: (1) the law of segregation, which states that two alleles for a heritable character separate during gamete formation and end up in different gametes, and (2) the law of independent assortment, which states that each pair of alleles in a dihybrid cross segregate independently of each other pair of alleles during gamete formation. Furthermore, the laws of probability (the addition and multiplication rules) determine the likelihood of various crosses occuring in succession or simultaneously.
Thankfully, the authors of the textbook do warn students about the complexity of genetics that goes further than Mendel's rules. Different degrees of dominance, pleiotropy (one gene having multiple phenotypic effects), epistasis, and polygenic inheritance (multiple genes affect one character) all have an influence on the increasingly sophisticated world of heredity. Lastly, section 14.4 discusses a fraction of genetic illnesses that can occur due to mutation, abnormal allele function, or recessive disorders.
Big Ideas
3.A.3 The chromosomal basis of inheritance provides an understanding of the pattern of passage of genes from parent to offspring.
4.C.2 Environmental factors influence the expression of the genotype in an organism.
4.C.4 The diversity of species within an ecosystem may influence the stability of the ecosystem.
Artifact
The chapter on "simple" Mendelian genetics does not usually turn out to be as simple as expected. However, the experiments that Gregor Mendel performed and the laws he discovered are pivotal to the history of genetics in biology and engaging to learn about.
This famous scientist identified two laws of inheritance: (1) the law of segregation, which states that two alleles for a heritable character separate during gamete formation and end up in different gametes, and (2) the law of independent assortment, which states that each pair of alleles in a dihybrid cross segregate independently of each other pair of alleles during gamete formation. Furthermore, the laws of probability (the addition and multiplication rules) determine the likelihood of various crosses occuring in succession or simultaneously.
Thankfully, the authors of the textbook do warn students about the complexity of genetics that goes further than Mendel's rules. Different degrees of dominance, pleiotropy (one gene having multiple phenotypic effects), epistasis, and polygenic inheritance (multiple genes affect one character) all have an influence on the increasingly sophisticated world of heredity. Lastly, section 14.4 discusses a fraction of genetic illnesses that can occur due to mutation, abnormal allele function, or recessive disorders.
Big Ideas
3.A.3 The chromosomal basis of inheritance provides an understanding of the pattern of passage of genes from parent to offspring.
4.C.2 Environmental factors influence the expression of the genotype in an organism.
4.C.4 The diversity of species within an ecosystem may influence the stability of the ecosystem.
Artifact
Click on the document to the right to view the reading guide.
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Reflection
Completing the reading guide and practicing with Punnett squares allowed me to learn the rules of multiplication and addition in relation to basic genetic inheritance patterns. The reading guide, like all other reading guides, was quite helpful in considering the information of the chapter in a targeted way. It required me to apply the information from the textbook to actual problems and questions. The practice with monohybrid and dihybrid crosses made me understand how the genotypic and phenotypic ratios work, as well as why the multiplication and addition rules turn out to have the same answer as if I had counted by hand. Knowing how to construct a Punnett square was very helpful and necessary when completing genetics problems.
Completing the reading guide and practicing with Punnett squares allowed me to learn the rules of multiplication and addition in relation to basic genetic inheritance patterns. The reading guide, like all other reading guides, was quite helpful in considering the information of the chapter in a targeted way. It required me to apply the information from the textbook to actual problems and questions. The practice with monohybrid and dihybrid crosses made me understand how the genotypic and phenotypic ratios work, as well as why the multiplication and addition rules turn out to have the same answer as if I had counted by hand. Knowing how to construct a Punnett square was very helpful and necessary when completing genetics problems.
chapter 15 the chromosomal basis of inheritance
Overview
This topic can pose a challenge to some students as genetics gets much more complicated than simple dominant and recessive genes. Chapter 15 elaborates on unique aspects of heredity that are not covered by Mendelian genetics, such as sex-linked genes, chromosome behavior, recombination with linked genes, gene maps, and chromosomal genetic disorders.
One of the most difficult and important concepts in this chapter is the idea of linked genes, since they cause disparities in the expected genotypic and phenotypic ratios of a cross. Linked genes are usually inherited together, since they are near each other on a chromosome. However, recombination can occur, which causes a portion of the offspring to exhibit phenotypes unlike either parent. Crossing over accounts for this recombination of linked genes, resulting in a different combination of alleles than either parent possess. Linkage maps are based on these recombination frequencies. The farther apart two genes are, the more likely it is that they will separate during crossover and recombine. *See the videos under the "Artifact" section to learn more about the application and process of this concept. Linked genes cover only one aspect that accounts for unique inheritance patterns mentioned in this chapter. The various ways in which traits are passed on to offspring demonstrate how singular and significant each individual organism comes to be.
Big Ideas
3.A.4 The inheritance pattern of many traits cannot be explained by simple Mendelian genetics.
3.C.1 Changes in genotype can result in changes in phenotype.
Artifact
This topic can pose a challenge to some students as genetics gets much more complicated than simple dominant and recessive genes. Chapter 15 elaborates on unique aspects of heredity that are not covered by Mendelian genetics, such as sex-linked genes, chromosome behavior, recombination with linked genes, gene maps, and chromosomal genetic disorders.
One of the most difficult and important concepts in this chapter is the idea of linked genes, since they cause disparities in the expected genotypic and phenotypic ratios of a cross. Linked genes are usually inherited together, since they are near each other on a chromosome. However, recombination can occur, which causes a portion of the offspring to exhibit phenotypes unlike either parent. Crossing over accounts for this recombination of linked genes, resulting in a different combination of alleles than either parent possess. Linkage maps are based on these recombination frequencies. The farther apart two genes are, the more likely it is that they will separate during crossover and recombine. *See the videos under the "Artifact" section to learn more about the application and process of this concept. Linked genes cover only one aspect that accounts for unique inheritance patterns mentioned in this chapter. The various ways in which traits are passed on to offspring demonstrate how singular and significant each individual organism comes to be.
Big Ideas
3.A.4 The inheritance pattern of many traits cannot be explained by simple Mendelian genetics.
3.C.1 Changes in genotype can result in changes in phenotype.
Artifact
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Reflection
I finally understood linked genes! The videos above helped me immensely in actually grasping the concept of linked genes and how to construct gene maps. Though these two videos are 10 and 17 minutes long, I watched them a couple of times over the course of the year for review because the slow and detailed explanation gave me a very clear image of the material. I had already been introduced to the subject while reading the chapter and listening to the lecture in class, but I never quite got it until these two videos gave me that light-bulb moment. Once I practiced mapping the genes and watched Mr. Anderson's careful explanation, I felt much more secure with this topic. Some things are just harder than others to feel comfortable with, but now I can safely say that I understand the main ideas in Chapter 15.
I finally understood linked genes! The videos above helped me immensely in actually grasping the concept of linked genes and how to construct gene maps. Though these two videos are 10 and 17 minutes long, I watched them a couple of times over the course of the year for review because the slow and detailed explanation gave me a very clear image of the material. I had already been introduced to the subject while reading the chapter and listening to the lecture in class, but I never quite got it until these two videos gave me that light-bulb moment. Once I practiced mapping the genes and watched Mr. Anderson's careful explanation, I felt much more secure with this topic. Some things are just harder than others to feel comfortable with, but now I can safely say that I understand the main ideas in Chapter 15.
chapter 16 molecular basis of inheritance
Overview
The 16th chapter in the textbook covers the replication of DNA, also called deoxyribonucleic acid, or genetic information, or the molecular basis for inheritance. DNA has specific a sugar, phosphate, and sequences of A-T base pairs and G-C base pairs in the form of an antiparallel double helix, which almost looks like a twisty ladder.
In DNA replication each half of the "ladder" gets a new second half, which is called the semi-conservative model. Helicase is the enzyme that separates the original strands at the replication fork and allows the primer to signal DNA polymerase to synthesize a new strand. Since DNA is antiparallel, a leading strand that can be continuously elongated and a lagging strand that replicates in the opposite direction in a series of fragments both exist. DNA ligase must then join these Okazaki fragments on the lagging strand. Then, voilà, two strands exist where one used to be.
Mechanisms to check the accuracy of replication must also exist to check for mistakes. Nucleotide excision repair and telomeres protect the DNA strand from mutations and excessive shortening of the strand.
The 16th chapter in the textbook covers the replication of DNA, also called deoxyribonucleic acid, or genetic information, or the molecular basis for inheritance. DNA has specific a sugar, phosphate, and sequences of A-T base pairs and G-C base pairs in the form of an antiparallel double helix, which almost looks like a twisty ladder.
In DNA replication each half of the "ladder" gets a new second half, which is called the semi-conservative model. Helicase is the enzyme that separates the original strands at the replication fork and allows the primer to signal DNA polymerase to synthesize a new strand. Since DNA is antiparallel, a leading strand that can be continuously elongated and a lagging strand that replicates in the opposite direction in a series of fragments both exist. DNA ligase must then join these Okazaki fragments on the lagging strand. Then, voilà, two strands exist where one used to be.
Mechanisms to check the accuracy of replication must also exist to check for mistakes. Nucleotide excision repair and telomeres protect the DNA strand from mutations and excessive shortening of the strand.
Big Ideas
3.A.1 DNA, and in some cases RNA, is the primary source of heritable information.
3.C.1 Changes in genotype can result in changes in phenotype.
Artifact
View the file below to learn more about the details of DNA replication.
3.A.1 DNA, and in some cases RNA, is the primary source of heritable information.
3.C.1 Changes in genotype can result in changes in phenotype.
Artifact
View the file below to learn more about the details of DNA replication.
ch16_readingguide.pdf | |
File Size: | 1371 kb |
File Type: |
Reflection
The reading guide for Chapter 16 was very helpful to me for reviewing important vocabulary and learning the process of replication, as well as important facts about DNA in general. The various steps and enzymes involved in the process became more clear to me through the completion of these questions. Labeling diagrams and filling out charts always helped me to organize the information as well as my thoughts about the concepts. Coming up with short explanations that fit in the given space and make sense supports the learning process greatly.
The reading guide for Chapter 16 was very helpful to me for reviewing important vocabulary and learning the process of replication, as well as important facts about DNA in general. The various steps and enzymes involved in the process became more clear to me through the completion of these questions. Labeling diagrams and filling out charts always helped me to organize the information as well as my thoughts about the concepts. Coming up with short explanations that fit in the given space and make sense supports the learning process greatly.
chapter 17 from gene to protein
Overview
The central dogma of biology: DNA --> RNA --> PROTEIN
The arrows symbolize two key processes of life, which are transcription and translation. Transcription allows for the synthesis of mRNA from DNA, while translation allows for the synthesis of a polypeptide from mRNA. Both processes have an initiation, elongation, and termination phase.
RNA polymerase acts as the main enzyme in transcription and attaches to the promoter sequence of the DNA strand. Trancription factors mediate intiation. In elongation, RNA polymerase elongates the RNA strand in the 5' to 3' direction. The process terminates when the polyadenylation signal is transcribed and the mRNA is cut free by proteins. Before translation can occur in eukaryotes, mRNA processing must occur. The 5' cap and poly-A tail are added to protect the RNA strand and introns are spliced from the molecule by spliceosomes. The single stranded piece of genetic information can then exit the nucleus and find a ribosome for the next step.
Translation occurs in the cytoplasm after the mRNA, ribosome, and transferRNA come together. The initiation stage completes after the first tRNA molecule with the correct amino acid to match the AUG start codon binds. In elongation, new tRNAs bring amino acids to match the codons and the polypeptide gets longer. The process ends when the stop codon of the mRNA strand reaches the A site of the ribosome and no more amino acids join the polypeptide. The unfinished protein then goes on to become modified and targeted to specific locations.
Of course, this process can not always work perfectly, so substitutions, deletions, insertions, and frameshift mutations can result and sometimes cause significant damage. Nobody's perfect, you live and you learn it (even DNA strands :).
Big Ideas
3.A.1 DNA, and in some cases RNA, is the primary source of heritable information.
3.C.1 Changes in genotype can result in changes in phenotype.
Artifact
View the video below for an explanation of transcription and translation:
The central dogma of biology: DNA --> RNA --> PROTEIN
The arrows symbolize two key processes of life, which are transcription and translation. Transcription allows for the synthesis of mRNA from DNA, while translation allows for the synthesis of a polypeptide from mRNA. Both processes have an initiation, elongation, and termination phase.
RNA polymerase acts as the main enzyme in transcription and attaches to the promoter sequence of the DNA strand. Trancription factors mediate intiation. In elongation, RNA polymerase elongates the RNA strand in the 5' to 3' direction. The process terminates when the polyadenylation signal is transcribed and the mRNA is cut free by proteins. Before translation can occur in eukaryotes, mRNA processing must occur. The 5' cap and poly-A tail are added to protect the RNA strand and introns are spliced from the molecule by spliceosomes. The single stranded piece of genetic information can then exit the nucleus and find a ribosome for the next step.
Translation occurs in the cytoplasm after the mRNA, ribosome, and transferRNA come together. The initiation stage completes after the first tRNA molecule with the correct amino acid to match the AUG start codon binds. In elongation, new tRNAs bring amino acids to match the codons and the polypeptide gets longer. The process ends when the stop codon of the mRNA strand reaches the A site of the ribosome and no more amino acids join the polypeptide. The unfinished protein then goes on to become modified and targeted to specific locations.
Of course, this process can not always work perfectly, so substitutions, deletions, insertions, and frameshift mutations can result and sometimes cause significant damage. Nobody's perfect, you live and you learn it (even DNA strands :).
Big Ideas
3.A.1 DNA, and in some cases RNA, is the primary source of heritable information.
3.C.1 Changes in genotype can result in changes in phenotype.
Artifact
View the video below for an explanation of transcription and translation:
Reflection
The videos about biology from the Bozeman Science channel on YouTube helped me very much while studying for quizzes and exams in AP Bio. The slow and detailed explanations were exactly what I needed to listen to so I could understand various processes. Of course, the clever analogies made in the videos were fun and supported memorization of the information. Looking back, I know that the combination of lectures, textbook reading, animations, videos, experiments, and reading guides all worked together to help me understand info. For visual learners, teaching videos can be extremely beneficial while learning and studying.
The videos about biology from the Bozeman Science channel on YouTube helped me very much while studying for quizzes and exams in AP Bio. The slow and detailed explanations were exactly what I needed to listen to so I could understand various processes. Of course, the clever analogies made in the videos were fun and supported memorization of the information. Looking back, I know that the combination of lectures, textbook reading, animations, videos, experiments, and reading guides all worked together to help me understand info. For visual learners, teaching videos can be extremely beneficial while learning and studying.
chapter 18 Regulation of gene expression
Overview
Bacteria respond to environmental change by regulating gene transcription through operons, which consist of an operator, promoter, and the genes they control. The operator acts as a switch for the transcription and synthesis of certain proteins. Two types of operons exist: repressible and inducible. In a repressible operon, transcription is repressed when the repressor is activated. In an inducible operon, transcription is activated when the repressor is subdued. (View the image below for an example of an operon.)
Eukaryotic gene expression is regulated in a more complicated way. Transcription factors, histone acetylation and DNA methylation, distal control elements, enhancers, and activators all act together to coordinate the control of genes. Of course, regulation can also occur after transcription. Alternative RNA splicing, timing of mRNA degradation, initiation of translation, and protein processing as well as degradation serve as ways to manage the activity of proteins.
This chapter also explained how noncoding RNAs play roles in regulating gene expression, not a very simple concept to understand. MicroRNAs (miRNAs), RNA interference (RNAi), and small interfering RNAs (siRNAs) can regulate the activity of mRNA and regulate gene expression.
Furthermore, differential gene expression is also what leads to different kinds of cell types in developing multicellular organisms. The textbook goes into some detail about cell differentiation and determination, as well as what mechanisms control the development of cells and the entire organ (and limb) system.
Bacteria respond to environmental change by regulating gene transcription through operons, which consist of an operator, promoter, and the genes they control. The operator acts as a switch for the transcription and synthesis of certain proteins. Two types of operons exist: repressible and inducible. In a repressible operon, transcription is repressed when the repressor is activated. In an inducible operon, transcription is activated when the repressor is subdued. (View the image below for an example of an operon.)
Eukaryotic gene expression is regulated in a more complicated way. Transcription factors, histone acetylation and DNA methylation, distal control elements, enhancers, and activators all act together to coordinate the control of genes. Of course, regulation can also occur after transcription. Alternative RNA splicing, timing of mRNA degradation, initiation of translation, and protein processing as well as degradation serve as ways to manage the activity of proteins.
This chapter also explained how noncoding RNAs play roles in regulating gene expression, not a very simple concept to understand. MicroRNAs (miRNAs), RNA interference (RNAi), and small interfering RNAs (siRNAs) can regulate the activity of mRNA and regulate gene expression.
Furthermore, differential gene expression is also what leads to different kinds of cell types in developing multicellular organisms. The textbook goes into some detail about cell differentiation and determination, as well as what mechanisms control the development of cells and the entire organ (and limb) system.
Big Ideas
2.E.1 Timing and coordination of specific events are necessary for the normal development of an organism, and these events are regulated by a variety of mechanisms.
3.B.1 Gene regulation results in differential gene expression, leading to cell specialization.
3.B.2 A variety of inter-cellular and intracellular signal transmissions mediate gene expression.
4.A.3 Interactions between external stimuli & regulated gene expression result in specialization of cells, tissues, & organs.
Artifact
2.E.1 Timing and coordination of specific events are necessary for the normal development of an organism, and these events are regulated by a variety of mechanisms.
3.B.1 Gene regulation results in differential gene expression, leading to cell specialization.
3.B.2 A variety of inter-cellular and intracellular signal transmissions mediate gene expression.
4.A.3 Interactions between external stimuli & regulated gene expression result in specialization of cells, tissues, & organs.
Artifact
Click here to view the reading guide for Chapter 18:
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Click here to view some notes on gene regulation:
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Reflection
This chapter was quite difficult for me to grasp. Gene regulation posed a substantial challenge to me and I had to review and listen to the material multiple times. The reading guide helped some, however the idea of repressible and inducible operons and regulatory genes still confused me somewhat. After going over my notes and listening to the teacher's explanation, however, I did feel more secure. The picture that we copied down (in the file above) as we were being taught about gene regulation was very helpful in clearing up misconceptions and other confusing ideas. Now enhancers, activators, and negative control seem so much more manageable and clear in my mind.
This chapter was quite difficult for me to grasp. Gene regulation posed a substantial challenge to me and I had to review and listen to the material multiple times. The reading guide helped some, however the idea of repressible and inducible operons and regulatory genes still confused me somewhat. After going over my notes and listening to the teacher's explanation, however, I did feel more secure. The picture that we copied down (in the file above) as we were being taught about gene regulation was very helpful in clearing up misconceptions and other confusing ideas. Now enhancers, activators, and negative control seem so much more manageable and clear in my mind.
chapter 19 Viruses
Overview
Viruses are infectious particles that consist of genetic information surrounded by a capsid. Millions of them can fit on the head of a pin. Bacteriophages infect a host range of bacterial cells and then replicate there. The viral DNA is copied and transcribed into proteins. This assembles into new virus particles which lyse the cell and exit to infect more cells. This process is called the lytic cycle, in which the cell dies (see image below). In contrast, the lysogenic cycle allows for replication of the phage without host destruction because of a prophage, when viral DNA integrates into the bacterial chromosome.
Some viruses exhibit other qualities such as genetic information in the form as RNA and formation of viral envelopes when entering the host cell. Retroviruses, such as HIV, exhibit complicated replication since reverse transcriptase transcribes the RNA template into DNA with can then be used in the cell. HIV evolves rapidly, making it hard to treat, and is also a provirus, which integrates and never leaves the host's genome. Scary stuff.
Big Ideas
3.A.1 DNA, and in some cases RNA, is the primary source of heritable information.
3.C.3 Viral replication results in genetic variation, and viral infection can introduce genetic variation into the hosts.
Artifact
Viruses are infectious particles that consist of genetic information surrounded by a capsid. Millions of them can fit on the head of a pin. Bacteriophages infect a host range of bacterial cells and then replicate there. The viral DNA is copied and transcribed into proteins. This assembles into new virus particles which lyse the cell and exit to infect more cells. This process is called the lytic cycle, in which the cell dies (see image below). In contrast, the lysogenic cycle allows for replication of the phage without host destruction because of a prophage, when viral DNA integrates into the bacterial chromosome.
Some viruses exhibit other qualities such as genetic information in the form as RNA and formation of viral envelopes when entering the host cell. Retroviruses, such as HIV, exhibit complicated replication since reverse transcriptase transcribes the RNA template into DNA with can then be used in the cell. HIV evolves rapidly, making it hard to treat, and is also a provirus, which integrates and never leaves the host's genome. Scary stuff.
Big Ideas
3.A.1 DNA, and in some cases RNA, is the primary source of heritable information.
3.C.3 Viral replication results in genetic variation, and viral infection can introduce genetic variation into the hosts.
Artifact
Reflection
The image above was particularly helpful in understanding how bacteriophages infect and control a cell. The steps of this process needed to be outlined by students in the reading guide, which certainly aided the learning process. Connecting the different steps of infection to the images was very useful in learning about the lytic and also the lysogenic cycle. Visualizing the phases that the phage goes through inside of a cell allowed me to understand how the entire process works and clearly figure out the development and spread of a virus.
The image above was particularly helpful in understanding how bacteriophages infect and control a cell. The steps of this process needed to be outlined by students in the reading guide, which certainly aided the learning process. Connecting the different steps of infection to the images was very useful in learning about the lytic and also the lysogenic cycle. Visualizing the phases that the phage goes through inside of a cell allowed me to understand how the entire process works and clearly figure out the development and spread of a virus.
chapter 20 biotechnology
Overview
This chapter goes into detail on the manipulation of organisms and their components to make "useful" products. DNA cloning is used to make multiple copies of a gene which may amplify one gene of interest or produce a needed protein product. Restriction enzymes can cut up DNA at restriction sites to produce restriction fragments with sticky ends, which can form bonds with complementary sticky ends on other DNA molecules. This process can be very practical when using cloning vectors, such as plasmids that carry foreign DNA into a host cell.
A genomic library is made up of a set of cell clones that have plasmids with particular gene fragments from another organism, while a cDNA library has cloned cDNAs (made from mRNA) with a collection of genes that only represent part of the genome. There are a few methods used in biotechnology to screen, amplify, and analyze clones.
Big Ideas
3.A.1 DNA, and in some cases RNA, is the primary source of heritable information.
Artifact
Click here for the DNA fingerprinting experiment.
Reflection
The experiment in which we used gel electrophoresis and nucleic acid hybridization to identify the suspect that committed a crime was a great way to apply what we learned in Chapter 20 to a practical use of the methods of biotechnology. In this lab, I learned how restriction enzymes and gel electrophoresis work together to create an individual's DNA fingerprint, their unique pattern of DNA strands. Nucleic acid hybridization with a radioactive probe allowed us to analyze the DNA and compare the suspect DNA to the evidence more closely. The intricate method of comparing, analyzing, and creating DNA fingerprints can be used for important situations, like clearing up crimes.
This chapter goes into detail on the manipulation of organisms and their components to make "useful" products. DNA cloning is used to make multiple copies of a gene which may amplify one gene of interest or produce a needed protein product. Restriction enzymes can cut up DNA at restriction sites to produce restriction fragments with sticky ends, which can form bonds with complementary sticky ends on other DNA molecules. This process can be very practical when using cloning vectors, such as plasmids that carry foreign DNA into a host cell.
A genomic library is made up of a set of cell clones that have plasmids with particular gene fragments from another organism, while a cDNA library has cloned cDNAs (made from mRNA) with a collection of genes that only represent part of the genome. There are a few methods used in biotechnology to screen, amplify, and analyze clones.
- Nucleic acid hybridization allows scientists to detect a gene's DNA sequence by using a nucleic acid probe with a known sequence.
- Polymerase chain reaction (PCR) allows a specific target segment to be amplified in a test tube, while gel electrophoresis is a technique that separates restriction fragments by length with an electric charge and agar gel.
- Southern blotting detects specific DNA nucleotide sequences with gel electrophoresis, membrane transfer, and nucleic acid hybridization, while Northern blotting allows specific sequences to be detected from mRNA.
- DNA microarray assays allow all genes of an organism to be represented on a single glass slide.
Big Ideas
3.A.1 DNA, and in some cases RNA, is the primary source of heritable information.
Artifact
Click here for the DNA fingerprinting experiment.
Reflection
The experiment in which we used gel electrophoresis and nucleic acid hybridization to identify the suspect that committed a crime was a great way to apply what we learned in Chapter 20 to a practical use of the methods of biotechnology. In this lab, I learned how restriction enzymes and gel electrophoresis work together to create an individual's DNA fingerprint, their unique pattern of DNA strands. Nucleic acid hybridization with a radioactive probe allowed us to analyze the DNA and compare the suspect DNA to the evidence more closely. The intricate method of comparing, analyzing, and creating DNA fingerprints can be used for important situations, like clearing up crimes.
chapter 21 Genomes and their evolution
Overview
Scientists apply computational methods that can store and analyze biological data to the study of genomes and their functions. The sheer amount of genes in a genome makes it very difficult to examine without the help of a computer. However, with the help of computer programs catalogs of genes and proteins can be made to study biological systems.
Furthermore, genomes evolve through duplications, rearrangements, and mutations of DNA. Duplication of chromosome sets leads to polyploidy, which rarely contributes to evolution of genes. Alterations of chromosome structure can lead to two different populations and species divergence. Duplication may also sometimes lead to novel genes and different functions. Exon shuffling permits the mixing and matching of exons within a gene or between two separate genes, which could produce new proteins with new functions. Genome evolution occurs slowly through rearrangements and mistakes, which contributes to the changes that allow for the progression and variation of organisms.
Big Ideas
4.C.1 Variation in molecular units provides cells with a wider range of functions
Scientists apply computational methods that can store and analyze biological data to the study of genomes and their functions. The sheer amount of genes in a genome makes it very difficult to examine without the help of a computer. However, with the help of computer programs catalogs of genes and proteins can be made to study biological systems.
Furthermore, genomes evolve through duplications, rearrangements, and mutations of DNA. Duplication of chromosome sets leads to polyploidy, which rarely contributes to evolution of genes. Alterations of chromosome structure can lead to two different populations and species divergence. Duplication may also sometimes lead to novel genes and different functions. Exon shuffling permits the mixing and matching of exons within a gene or between two separate genes, which could produce new proteins with new functions. Genome evolution occurs slowly through rearrangements and mistakes, which contributes to the changes that allow for the progression and variation of organisms.
Big Ideas
4.C.1 Variation in molecular units provides cells with a wider range of functions
Artifact
Click here to view an example of my personal notes on the chapter:
Click here to view an example of my personal notes on the chapter:
ch21_notes.pdf | |
File Size: | 1059 kb |
File Type: |
Reflection
The file above contains an example of my notes on the required reading for this chapter. This example is similar to all of my other notes about other chapters. I organize the information into sections that model the textbook. Taking notes on the information that I read helps to process the concepts and review later on. Notes can always serve as a resource for studying and helping to understand and create a compact version of chapters like the one on genome evolution.
The file above contains an example of my notes on the required reading for this chapter. This example is similar to all of my other notes about other chapters. I organize the information into sections that model the textbook. Taking notes on the information that I read helps to process the concepts and review later on. Notes can always serve as a resource for studying and helping to understand and create a compact version of chapters like the one on genome evolution.