1. What is "Lucy" and how did it get its name?
Lucy is a fossil of the A. afarensis species and shows some of the earliest human ancestors. It got its name from the song "Lucy in the Sky with Diamonds" which was a song that was playing.
2. Which hominid species does this activity focus on?
A. afarensis
3. Why do scientists believe these species all belong to the same family?
Found various fossils and were known as the First Family. They were the remains of 13 individuals and had characteristics that showed they were similar from one another species.
4. How old is each set of fossils shown in this activity?
Both the First Family fossil set and Lucy are 3.2 million years old, the Hadar Skull is 3.0 million years old & the Laetoli Footprints are 3.6 million years old.
5. Based on the description of each set of bones and the footprints, did this species live in trees or on land? Explain and defend your answer by referencing the evidence in your explanation.
I believe land, because Lucy's leg bones showed it being angular inwards as in humans
6. How did males and females of this species differ?
Males have larger muscle scars and females have a wider pelvic inlet.
7. How did the brains of this species compare to modern humans? What evidence supports this?
Small-sized brains about the size of chimps
Friday, April 30, 2010
Humans: Babies By Design
There are always pros and cons especially for creating babies by design. It would be quite fortunate if all babies were genetically modified so that they wouldn't have an inevitable death because of a disease, but parents on their own should be aware of any genetic diseases that might affect them in creating a baby. However, I would most likely support the should not create babies by design, because our genetic code creates our own individualism and that's something I find as aesthetic.
Humans: Origins of Humankind
Species that lead to humans:
Orrorin tugensis
Australopithecus anamensis
Kenyanthropus platyops
Homo habilis
Homo erectus
Homo sapiens
Orrorin tugensis
Australopithecus anamensis
Kenyanthropus platyops
Homo habilis
Homo erectus
Homo sapiens
Survival: Microbe Clock
A) Describe in detail how Streptococcus pneumoniae has developed antibiotic resistance over the past century.
Streptococcus pneumonia has developed resistance over time against antibiotics and over drugs. Those bacteria that remain rapidly evolve and replicate leaving those that are susceptible to die out, and leaving the ones which are resistant to survive.
B) Start the clock. The one minute of division here represents 186 days of actual division. How many times did the cells divide in this time? How many total cells resulted at the end of this time? How many mutations occcurred in the population during this time?
Replicated 13,391 million times; population of 313, 753 million; 1,326 mutations
Streptococcus pneumonia has developed resistance over time against antibiotics and over drugs. Those bacteria that remain rapidly evolve and replicate leaving those that are susceptible to die out, and leaving the ones which are resistant to survive.
B) Start the clock. The one minute of division here represents 186 days of actual division. How many times did the cells divide in this time? How many total cells resulted at the end of this time? How many mutations occcurred in the population during this time?
Replicated 13,391 million times; population of 313, 753 million; 1,326 mutations
Change: Deep Time
1. Atmosphere forms: Precambrian Eon; Hadean 4,500 mya
2. Earth's core forms: Precambrian Eon; Hadean 4,400 mya
3. First living organisms evolve(prokaryotic cells): Precambrian Eon; Hadean 3,850 mya
4.First eukaryotic cells evolve: Precambrian Eon; Archaean 2,700 mya
5. First multicellular organisms evolve(algae): Precambrian Eon; Proterozoic 1,200 mya
6. Ozone layer forms: Precambrian Eon; Proterozoic 600 mya
7. First Chordates evolve: Paleozoic Era; Cambrian 535 mya
A chordate are any of the numerous animals belonging to the the family Chordata having at some stage of development a dorsal nerve cord.
8. First land plants evolve: Paleozoic Era; Ordovician 480 mya
9. First land animals (bugs) evolve: Paleozoic Era; Carboniferons 420 mya
10. First land vertebrates evolve: Paleozoic Era; Devonian 375 mya
A vertebrate is an animal having a backbone or spinal column.
11. First flowering plants evolved: Paleozoic Era; Devonian 360 mya
12. First reptiles evolve: Paleozoic Era; Permian 275 mya
13. Pangaea forms: Paleozoic Era; Permian 280 mya
The Pangaea is a theory that states that all present continents were once together and collectively known as a "supercontinent" called Pangaea.
14. First mammals evolve: Mesozoic Era; Triassic 220 mya
15. First birds evolv: Mesozoic Era; Jurassic 150 mya
16. First primates evolve: Cenozoic Era; Paleocene 60mya
17. Continents reach their present-day formation: Cenozoic Era; Eocene 40mya
18. First apes evolve from the primate lineage: Cenozoic Era; Oligocene 25 mya
19. Hominids evolve from the ape lineage: Cenozoic Era; Pliocene 5.2 mya
A hominid is any member of the biological primate family Hominidae.
20. First early humans evolve from the hominid lineage: Cenozoic Era; Pleistocene 0.16 mya
21. Modern humans evolve from the human lineage: Cenozoic Era; Pleistocene 0.1 mya
2. Earth's core forms: Precambrian Eon; Hadean 4,400 mya
3. First living organisms evolve(prokaryotic cells): Precambrian Eon; Hadean 3,850 mya
4.First eukaryotic cells evolve: Precambrian Eon; Archaean 2,700 mya
5. First multicellular organisms evolve(algae): Precambrian Eon; Proterozoic 1,200 mya
6. Ozone layer forms: Precambrian Eon; Proterozoic 600 mya
7. First Chordates evolve: Paleozoic Era; Cambrian 535 mya
A chordate are any of the numerous animals belonging to the the family Chordata having at some stage of development a dorsal nerve cord.
8. First land plants evolve: Paleozoic Era; Ordovician 480 mya
9. First land animals (bugs) evolve: Paleozoic Era; Carboniferons 420 mya
10. First land vertebrates evolve: Paleozoic Era; Devonian 375 mya
A vertebrate is an animal having a backbone or spinal column.
11. First flowering plants evolved: Paleozoic Era; Devonian 360 mya
12. First reptiles evolve: Paleozoic Era; Permian 275 mya
13. Pangaea forms: Paleozoic Era; Permian 280 mya
The Pangaea is a theory that states that all present continents were once together and collectively known as a "supercontinent" called Pangaea.
14. First mammals evolve: Mesozoic Era; Triassic 220 mya
15. First birds evolv: Mesozoic Era; Jurassic 150 mya
16. First primates evolve: Cenozoic Era; Paleocene 60mya
17. Continents reach their present-day formation: Cenozoic Era; Eocene 40mya
18. First apes evolve from the primate lineage: Cenozoic Era; Oligocene 25 mya
19. Hominids evolve from the ape lineage: Cenozoic Era; Pliocene 5.2 mya
A hominid is any member of the biological primate family Hominidae.
20. First early humans evolve from the hominid lineage: Cenozoic Era; Pleistocene 0.16 mya
21. Modern humans evolve from the human lineage: Cenozoic Era; Pleistocene 0.1 mya
Darwin: An Origin of Species activity
Overview: Hurricane hits the mainland and forces many pollenpeepers offshore islands and struggle to survive. The birds that are well adapted will survive will pass their genes, while those that aren't will wither out.
5mya: Hurricane hits and blows off the pollenpeepers to 3 other offshore lands - Windsor Island, Norcross Island, and Warwick Archipelago.
4mya: Population grows on all 4 lands.
3mya: In mainland, a beak suited better for the environment grows. Food abundance rises and predators (lizards) come ashore on the Norcross.
2mya: Mainland habitat becomes more lush, providing more food for the environment. On Windsor Island, some move back mainland. On the Warwick Archipelago, population diversifies
1mya: Mainland - mainland and Windsor birds interbreed. Warwick Archipelago - lowland forest population begins feeding on nectar. Immigrants come to the Windsor Island and Norcross.
Present: Windor Island - short blunt beaks become obsolete. Norcross - some specialize in seedeaters.
5mya: Hurricane hits and blows off the pollenpeepers to 3 other offshore lands - Windsor Island, Norcross Island, and Warwick Archipelago.
4mya: Population grows on all 4 lands.
3mya: In mainland, a beak suited better for the environment grows. Food abundance rises and predators (lizards) come ashore on the Norcross.
2mya: Mainland habitat becomes more lush, providing more food for the environment. On Windsor Island, some move back mainland. On the Warwick Archipelago, population diversifies
1mya: Mainland - mainland and Windsor birds interbreed. Warwick Archipelago - lowland forest population begins feeding on nectar. Immigrants come to the Windsor Island and Norcross.
Present: Windor Island - short blunt beaks become obsolete. Norcross - some specialize in seedeaters.
Sunday, April 4, 2010
1. Which regulatory mechanisms occur at the DNA-level, which occur at the protein-level?
DNA level - transcription, chromosome remodeling, acetylation/methylation, activators/repressors, siRNA
protein level - feedback inhibition; allosteric/competitive inhibition
2. How do acetylation, methylation, repressors, activators, and siRNA control gene expression? What role do inducers play?
Acetylation loosens the DNA, allowing transcription factors to bind
Methylation is the opposite of acetylation, it crams the DNA close together to that it denies access
Repressor binds to regulatory sites blocking attachment of transcription factors
Activators binds to the regulatory sites
Inducers are crucial since they have the ability to control repressors and activators
3. What is an enhancer and how does it help control how much of a particular protein is made?
An enhancer is a short region of DNA that can bind to activators - are far from the promoter site. Enhancers increase the transcription process, therefore increasing amount of protein to be made.
4. How do allosteric inhibition and competitive inhibition differ in the ways they accomplish feedback inhibition?
Allosteric inhibition binds, changing the shape of the enzyme, while competitive inhibition gets in the way by blocking the entrance to an enzyme
5. What are the three phases of the cell cycle? What occurs at each phase?
G1, S, and G2 phase. G1 and G2 is similar in that they are the phase were the cell is given time to grow to its stable size, and in the S phase, DNA synthesis occurs
6. What are the four phases of mitosis? What occurs at each phase?
Prophase - DNA condenses and mitotic spindles start to develop
Metaphase - Linear alignment of chromatids at the center of the cell
Anaphase - Mitotic spindles pull the sister chromatids apart so that they are on each side of the cell
Telophase/Cytokinesis - Nuclear envelop reforms and the cell is divided by the cell membranes separating
7. What are cell cycle checkpoints? Why are they important?
Cell cycle checkpoints are areas where the enzymes examine whether or not the cell cycle is progressing properly to prevent mutations or problems that can occur.
8.What is apoptosis? What role does it play in the cell cycle?
Apoptosis is when a cell "suicides" or kills itself, it helps in the cell cycle so that it prevents further cell division in mutated cells
9. What is the difference between chromatin and chromosomes?
Chromosomes are condensed versions of chromatin.
10. What is the role of the centromere? (What would happen without it?)
Centromere holds the sister chromatids together, without it anaphase would most likely not correctly separate to each side of the cell (the whole chromosome might go to one side).
11. What is the difference between a chromatid and a chromosome?
Two strands of chromatid forms a chromosome
12. What events must happen in order for two sister chromatids to separate from one another and move to opposite sides of the cell? (What happens at the centromere? What happens to the centromere? What is the role of the mitotic spindle?)
The kinetochore microtubules connect to the sister chromatids and line up during metaphase. During Anaphase, the sister chromatids are pulled apart, and the centromere that hold them together are actually proteins that deactivate allowing, the separation of them. The mitotic spindles are shortened and are turned into centrioles and conserved for future mitosis processes
13. What would happen if two sister chromatids moved to the same side of the cell?
Of the pair of cell through mitosis, one will have an abundance of chromosomes, while the other cell will be lacking.
14. What happens to the mitotic spindle after mitosis?
Forms into the cytoskeleton and returns back into shape of microtubules and centrioles
15. What are gametes? Where are they made in the body? How are they made?
Sex cells; eggs in females made in the ovaries, or sperm in the male made in the testes; made by meiosis
16. What are the eight phases of meiosis? What occurs during each phase? How does meiosis differ from mitosis?
Prophase I - DNA condenses and microtubles start to assembles.
Metaphase I - Homologous chromosomes alignment at center of cell; crossing over occurs
Anaphase I - Separation of homologous chromosomes
Telophase/Cytokinesis I - Cell is divided, both daughter cell gets 23 pairs of chromatids each; results in two haploids
Prophase II - Microtubules prepare for Metaphase II
Metaphase II - 23 chromatid pairs line up at the center
Anaphase II - Centromere divide and split the the 46 chromosomes; sister chromatids by mitosis
Telophase/Cytokinesis II - Divides both cells into halves, making four haploids (gametes)
17. How do crossing over and random assortment “mix up” genes so that children are genetically different from their parents?
Crossing over occurs on any part of the chromosome and since there are so much DNA in the chromosome, there are a number of possibilities where crossing over can occur. Random assortment further helps but most of the genetic variation is due to crossing over.
18. Why are insertion and deletion mutations usually more harmful than substitution mutations?
Insertion and deletion mutations is more harmful because substitution is more likely to an equivalent condon since there are 20 codons for 64 different combinations.
19. How does nondisjunction affect the genes present in an organism? Specifically, why does it cause deformities?
Nondisjunction affects cells undergoing division and result in an extra or missing one chromosome.
20. What “super powers” must a cell acquire to become cancerous? How does it acquire these powers?
Active oncogenes and inactive tumor suppressor genes; by mutation which can alter these gene's control of activation and deactivation.
21. Compare and contrast oncogenes and tumor suppressor genes. What are they? How are they similar? How are they different?
Oncogenes and tumor suppressor genes both play a role in controlling cell division. Oncogenes tells cells to keep dividing while tumor suppressor genes halt or slow the process of cell division. Oncogenes help cancer, tumor suppressors help against cancer.
22. Why is cancer primarily a disease of old age?
In old age, the wear in the body's immune system and all the regulatory functions can allow a cancerous to take advantage by "cheating the system."
23. How do mutations cause genetic variation? Is this good or bad for the organism?
Mutations can create new alleles which is expressed as a new genotype. Normally it is bad, since it can cause a defect in the organism, but if it's good, it's considered evolution
24. How do genetic diseases caused by point mutations differ from those caused by chromosomal mutations like nondisjunction?
Chromosomal mutations affect a large number of DNA vs point mutations which cause a frame change in the DNA sequence
25. What causes spontaneous mutations? What causes induced mutations?
Spontaneous mutations are caused by point mutations or nondisjunction incurred during mitosis. Induced mutations are caused by mutagens.
26. How accurate is DNA replication? (That is, how often do point mutations occur?)
Errors from point mutations occur in about every 1 in 100,000 nucleotides; when an enzyme tries to fix the problem, the error rate drops to about 1 in 10 billion nucleotides in humans.
27. What type of mutation is shown here? AGTGCCGTAAC
___________________________________TCACGGCCAGTG
Point mutations (both frameshift - a nucleotide was added - and substitution)
DNA level - transcription, chromosome remodeling, acetylation/methylation, activators/repressors, siRNA
protein level - feedback inhibition; allosteric/competitive inhibition
2. How do acetylation, methylation, repressors, activators, and siRNA control gene expression? What role do inducers play?
Acetylation loosens the DNA, allowing transcription factors to bind
Methylation is the opposite of acetylation, it crams the DNA close together to that it denies access
Repressor binds to regulatory sites blocking attachment of transcription factors
Activators binds to the regulatory sites
Inducers are crucial since they have the ability to control repressors and activators
3. What is an enhancer and how does it help control how much of a particular protein is made?
An enhancer is a short region of DNA that can bind to activators - are far from the promoter site. Enhancers increase the transcription process, therefore increasing amount of protein to be made.
4. How do allosteric inhibition and competitive inhibition differ in the ways they accomplish feedback inhibition?
Allosteric inhibition binds, changing the shape of the enzyme, while competitive inhibition gets in the way by blocking the entrance to an enzyme
5. What are the three phases of the cell cycle? What occurs at each phase?
G1, S, and G2 phase. G1 and G2 is similar in that they are the phase were the cell is given time to grow to its stable size, and in the S phase, DNA synthesis occurs
6. What are the four phases of mitosis? What occurs at each phase?
Prophase - DNA condenses and mitotic spindles start to develop
Metaphase - Linear alignment of chromatids at the center of the cell
Anaphase - Mitotic spindles pull the sister chromatids apart so that they are on each side of the cell
Telophase/Cytokinesis - Nuclear envelop reforms and the cell is divided by the cell membranes separating
7. What are cell cycle checkpoints? Why are they important?
Cell cycle checkpoints are areas where the enzymes examine whether or not the cell cycle is progressing properly to prevent mutations or problems that can occur.
8.What is apoptosis? What role does it play in the cell cycle?
Apoptosis is when a cell "suicides" or kills itself, it helps in the cell cycle so that it prevents further cell division in mutated cells
9. What is the difference between chromatin and chromosomes?
Chromosomes are condensed versions of chromatin.
10. What is the role of the centromere? (What would happen without it?)
Centromere holds the sister chromatids together, without it anaphase would most likely not correctly separate to each side of the cell (the whole chromosome might go to one side).
11. What is the difference between a chromatid and a chromosome?
Two strands of chromatid forms a chromosome
12. What events must happen in order for two sister chromatids to separate from one another and move to opposite sides of the cell? (What happens at the centromere? What happens to the centromere? What is the role of the mitotic spindle?)
The kinetochore microtubules connect to the sister chromatids and line up during metaphase. During Anaphase, the sister chromatids are pulled apart, and the centromere that hold them together are actually proteins that deactivate allowing, the separation of them. The mitotic spindles are shortened and are turned into centrioles and conserved for future mitosis processes
13. What would happen if two sister chromatids moved to the same side of the cell?
Of the pair of cell through mitosis, one will have an abundance of chromosomes, while the other cell will be lacking.
14. What happens to the mitotic spindle after mitosis?
Forms into the cytoskeleton and returns back into shape of microtubules and centrioles
15. What are gametes? Where are they made in the body? How are they made?
Sex cells; eggs in females made in the ovaries, or sperm in the male made in the testes; made by meiosis
16. What are the eight phases of meiosis? What occurs during each phase? How does meiosis differ from mitosis?
Prophase I - DNA condenses and microtubles start to assembles.
Metaphase I - Homologous chromosomes alignment at center of cell; crossing over occurs
Anaphase I - Separation of homologous chromosomes
Telophase/Cytokinesis I - Cell is divided, both daughter cell gets 23 pairs of chromatids each; results in two haploids
Prophase II - Microtubules prepare for Metaphase II
Metaphase II - 23 chromatid pairs line up at the center
Anaphase II - Centromere divide and split the the 46 chromosomes; sister chromatids by mitosis
Telophase/Cytokinesis II - Divides both cells into halves, making four haploids (gametes)
17. How do crossing over and random assortment “mix up” genes so that children are genetically different from their parents?
Crossing over occurs on any part of the chromosome and since there are so much DNA in the chromosome, there are a number of possibilities where crossing over can occur. Random assortment further helps but most of the genetic variation is due to crossing over.
18. Why are insertion and deletion mutations usually more harmful than substitution mutations?
Insertion and deletion mutations is more harmful because substitution is more likely to an equivalent condon since there are 20 codons for 64 different combinations.
19. How does nondisjunction affect the genes present in an organism? Specifically, why does it cause deformities?
Nondisjunction affects cells undergoing division and result in an extra or missing one chromosome.
20. What “super powers” must a cell acquire to become cancerous? How does it acquire these powers?
Active oncogenes and inactive tumor suppressor genes; by mutation which can alter these gene's control of activation and deactivation.
21. Compare and contrast oncogenes and tumor suppressor genes. What are they? How are they similar? How are they different?
Oncogenes and tumor suppressor genes both play a role in controlling cell division. Oncogenes tells cells to keep dividing while tumor suppressor genes halt or slow the process of cell division. Oncogenes help cancer, tumor suppressors help against cancer.
22. Why is cancer primarily a disease of old age?
In old age, the wear in the body's immune system and all the regulatory functions can allow a cancerous to take advantage by "cheating the system."
23. How do mutations cause genetic variation? Is this good or bad for the organism?
Mutations can create new alleles which is expressed as a new genotype. Normally it is bad, since it can cause a defect in the organism, but if it's good, it's considered evolution
24. How do genetic diseases caused by point mutations differ from those caused by chromosomal mutations like nondisjunction?
Chromosomal mutations affect a large number of DNA vs point mutations which cause a frame change in the DNA sequence
25. What causes spontaneous mutations? What causes induced mutations?
Spontaneous mutations are caused by point mutations or nondisjunction incurred during mitosis. Induced mutations are caused by mutagens.
26. How accurate is DNA replication? (That is, how often do point mutations occur?)
Errors from point mutations occur in about every 1 in 100,000 nucleotides; when an enzyme tries to fix the problem, the error rate drops to about 1 in 10 billion nucleotides in humans.
27. What type of mutation is shown here? AGTGCCGTAAC
___________________________________TCACGGCCAGTG
Point mutations (both frameshift - a nucleotide was added - and substitution)
Saturday, April 3, 2010
Tour of the Basics
http://learn.genetics.utah.edu/content/begin/tour/
What Is DNA?
DNA (deoxyribose nucleic acid) is double helix structured composed of two strands of A, T, G, and Cs that combine with each other in the complimentary strand, by specific pairs - A with T and G with C - and each collectively, are used in a gene.
What is a Gene?
Genes are made up of DNA and are specific in building proteins. If there is an error or mutation within the gene, it will cause a disorder and may be disadvantageous. Since genes contain instructions for building proteins, there are in fact many sorts of a proteins, which result in functions for all sorts of things.
What is a Chromosome?
A chromosome is a packaged fit of DNA into a cell. Depending on the organism, each cell holds a different number of chromosomes, for humans, a cell holds 46 chromosomes. By looking at chromosomes, you can observe something such as the sex of a human for example; you can see the difference between female chromosome (XX) and male chromosome (XY).
What is a Protein?
Each protein has a specific role such as receptor proteins, sending signals across the nerve cells into the brain, or structural to make the cell stay in it's shape. There are many types of proteins other than these two that play specific roles in the body. To make proteins, it uses genes as it's "blueprint" by making mRNA then travels with later is moved into the ribosomes to produce more.
What is Heredity?
Heredity is the set of traits that defined by our genes. It is both contributed by environmental factors (chemical exposure) and the chromosomes inherited from our parents, both father and mother. Because of random assortment, each child will never have the exact combination of chromosomes.
What is a Trait?
A trait is a unique feature that separates one person from another noticeably. There are three types, physical behavioral, or predisposition on medical condition. Each can be genetically or environmentally influenced. The genes or alleles passed on by both parents (one from each) determine what trait someone will have.
What Is DNA?
DNA (deoxyribose nucleic acid) is double helix structured composed of two strands of A, T, G, and Cs that combine with each other in the complimentary strand, by specific pairs - A with T and G with C - and each collectively, are used in a gene.
What is a Gene?
Genes are made up of DNA and are specific in building proteins. If there is an error or mutation within the gene, it will cause a disorder and may be disadvantageous. Since genes contain instructions for building proteins, there are in fact many sorts of a proteins, which result in functions for all sorts of things.
What is a Chromosome?
A chromosome is a packaged fit of DNA into a cell. Depending on the organism, each cell holds a different number of chromosomes, for humans, a cell holds 46 chromosomes. By looking at chromosomes, you can observe something such as the sex of a human for example; you can see the difference between female chromosome (XX) and male chromosome (XY).
What is a Protein?
Each protein has a specific role such as receptor proteins, sending signals across the nerve cells into the brain, or structural to make the cell stay in it's shape. There are many types of proteins other than these two that play specific roles in the body. To make proteins, it uses genes as it's "blueprint" by making mRNA then travels with later is moved into the ribosomes to produce more.
What is Heredity?
Heredity is the set of traits that defined by our genes. It is both contributed by environmental factors (chemical exposure) and the chromosomes inherited from our parents, both father and mother. Because of random assortment, each child will never have the exact combination of chromosomes.
What is a Trait?
A trait is a unique feature that separates one person from another noticeably. There are three types, physical behavioral, or predisposition on medical condition. Each can be genetically or environmentally influenced. The genes or alleles passed on by both parents (one from each) determine what trait someone will have.
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