Inheritance
II. Connections
a. Gene Locus & Disulfide Bridge: A disulfide bridge is a bond between sulfur atoms in neighboring cysteine amino acids. This bond occurs in protein folding to create different proteins. DNA in the nucleus code for the making of proteins. DNA strands are very long and can code for various genes. A gene locus is the specific location of certain genes.
b. Non-disjunction & 9-triplet Pattern: Non-disjunction is the failure of sister chromatids or homologous chromosomes to separate in meiosis or mitosis. This results in daughter cells having too many or too few chromosomes. The microtubules that form the spindle fibers that attach to the kinetochores of the chromosomes are made in a 9-triplet pattern.
c. Autosome & Steroid: Autosomes are the other chromosomes in body cells that are the same in both sexes. This is similar to the steroids all people have in common, such as cholesterol. Steroids, such as estrogen and testosterone, that are gender specific are similar to the sex chromosomes are specific chromosomes that determine gender.
d. Polygenic & Glycocalyx: Polygenic inheritance is the inheritance of multiple genes that affect the same trait. This helps influence genetic variations in DNA, that leads to the evolution of cells, similar to the evolution of eukaryotic cells. Because eukaryotic cells are more developed than prokaryotic cells, they do not have a glycocalyx, which is a ,eshlike capsul around the prokaryotic cell wall.
III. Few Essentials
a. Mendel's law of segregation states that genes of homologous chromosomes are separated from each other during meiosis, so that one version of each ends up in different gametes. Mendel's law of independent assortment states that genes are sorted individually from other genes during meiosis. Both laws give rise to genetic variations of traits. The law of segregation during meiosis, when the chromosomes are being pulled apart to opposite poles of the cell so that they end up in different gametes. The law of independent assortment occurs after meiosis, when the chromosomes have already been sorted for distribution, and occur independently from other types of genes.
Sunday, February 13, 2011
Friday, February 4, 2011
Ch. 10
Cell Reproduction
II. Connections
1. Homologous chromosome & Duplicated chromosome
At the beginning of a cell's life cycle, a cell has 23 pairs of homologous chromosomes. A homologous chromosome is one chromosome in a pair that have the same genes, but one version given from the mom and the other version given from the dad. A duplicated chromosome is a pair of chromosomes that are completely identical to each other. A cell has duplicated chromosomes after S-phase, when all the DNA in a cell is copied.
2. Kinetochore & Microtubule Organizing Center (MTOC)
In an animal cell, the MTOC is a centrosome. This is the place where microtubule spindle fibers develop and grow. They connect to the kinetochores attached to the centromeres of the chromosomes during the prophase stage. The spindle fibers shorten starting from the centrosomes, pulling the chromosomes apart.
3. Haploid & Somatic
A somatic cell is any cell in the body that is not a germ cell. The only cells in the body that are haploid are gametes, or reproductive cells. Haploid cells only have half of the DNA a normal cell, or diploid cell, has. This is because the reproductive cells from the mom and from the dad will come together during reproduction and fertilize a zygote, a diploid cell.
4. Nucleosome & Dehydration Reaction
A nucleosome is a small stretch of DNA wound twice around a spool of proteins called a histone. Proteins are made up of amino acids linked together by peptide bonds. They form in a dehydration reaction because the OH molecule on the carboxyl group and the H atom in the amino group bond together forming water, which is lost during this processs
III. Few Essentials
1. Chromosomes during Meiosis
A. Prophase 1: chromosomes are in thread-like form; homologous pairs are together; swap segments
B. Metaphase 1: homologous chromosomes line up next to each other along the midway line of the cell
C. Anaphase 1: spindle fibers pull apart homologous chromosomes
D. Telophase 1: homologous chromosomes are now in different ends of the cell; all chromosomes are still duplicated
E. Prophase 2: no new DNA replication has occurred; spindle fibers attach to each chromosome
F. Metaphase 2: all chromosomes line up along the midway of the cell
G. Anaphase 2: attachment between sister chromatids of each chromosome breaks; one of each type of chromosome is moving towards the ends of the cell
H. Telophase 2: 4 cells result with a haploid number of chromosomes
2. Outline 10.4
I. Crossing Over in Prophase 1
A. All chromosomes in a germ cell condense in the same way
1. drawn close to its homologue
2. chromatids of 1 become stitched to chromatids of another
a. favors crossing over
3. 2 "nonsister" chromatids swap genes
B. Genes come in different forms- alleles
1. crossing over: chance to swap slightly different versions of information on gene products
2. crossing over leads to recombinations among genes of homologous chromosomes, and eventually to variation in traits among offspring
II. Metaphase 1 Alignments
A. major shufflings of chromosomes: transition from prophase 1 to metaphase 1
1. no particular pattern to the metaphase 1 positions of chromosomes
2. either homologous partner can end up at either spindle pole
3. 8,388,608 possible combinations of chromosomes
3. Similarities & Differences
Similarities
II. Connections
1. Homologous chromosome & Duplicated chromosome
At the beginning of a cell's life cycle, a cell has 23 pairs of homologous chromosomes. A homologous chromosome is one chromosome in a pair that have the same genes, but one version given from the mom and the other version given from the dad. A duplicated chromosome is a pair of chromosomes that are completely identical to each other. A cell has duplicated chromosomes after S-phase, when all the DNA in a cell is copied.
2. Kinetochore & Microtubule Organizing Center (MTOC)
In an animal cell, the MTOC is a centrosome. This is the place where microtubule spindle fibers develop and grow. They connect to the kinetochores attached to the centromeres of the chromosomes during the prophase stage. The spindle fibers shorten starting from the centrosomes, pulling the chromosomes apart.
3. Haploid & Somatic
A somatic cell is any cell in the body that is not a germ cell. The only cells in the body that are haploid are gametes, or reproductive cells. Haploid cells only have half of the DNA a normal cell, or diploid cell, has. This is because the reproductive cells from the mom and from the dad will come together during reproduction and fertilize a zygote, a diploid cell.
4. Nucleosome & Dehydration Reaction
A nucleosome is a small stretch of DNA wound twice around a spool of proteins called a histone. Proteins are made up of amino acids linked together by peptide bonds. They form in a dehydration reaction because the OH molecule on the carboxyl group and the H atom in the amino group bond together forming water, which is lost during this processs
III. Few Essentials
1. Chromosomes during Meiosis
A. Prophase 1: chromosomes are in thread-like form; homologous pairs are together; swap segments
B. Metaphase 1: homologous chromosomes line up next to each other along the midway line of the cell
C. Anaphase 1: spindle fibers pull apart homologous chromosomes
D. Telophase 1: homologous chromosomes are now in different ends of the cell; all chromosomes are still duplicated
E. Prophase 2: no new DNA replication has occurred; spindle fibers attach to each chromosome
F. Metaphase 2: all chromosomes line up along the midway of the cell
G. Anaphase 2: attachment between sister chromatids of each chromosome breaks; one of each type of chromosome is moving towards the ends of the cell
H. Telophase 2: 4 cells result with a haploid number of chromosomes
2. Outline 10.4
I. Crossing Over in Prophase 1
A. All chromosomes in a germ cell condense in the same way
1. drawn close to its homologue
2. chromatids of 1 become stitched to chromatids of another
a. favors crossing over
3. 2 "nonsister" chromatids swap genes
B. Genes come in different forms- alleles
1. crossing over: chance to swap slightly different versions of information on gene products
2. crossing over leads to recombinations among genes of homologous chromosomes, and eventually to variation in traits among offspring
II. Metaphase 1 Alignments
A. major shufflings of chromosomes: transition from prophase 1 to metaphase 1
1. no particular pattern to the metaphase 1 positions of chromosomes
2. either homologous partner can end up at either spindle pole
3. 8,388,608 possible combinations of chromosomes
3. Similarities & Differences
Similarities
- starting cell is a diploid cell
- all chromosomes are duplicated from interphase
- both use spindles to sort and move chromosomes
Differences
- mitosis ends with 2 diploid cells; meiosis ends with 4 haploid cells
- mitosis happens in any part of the body; meiosis only occurs in the reproductive organs
- mitosis: basis of asexual reproduction and growth and tissue repair; meiosis: required step before the formation of gametes or sexual spores
Sunday, January 23, 2011
Ch. 45 & 47 & 48
Ecology II
II. Connections
a. Carrying Capacity & Biotic Potential
The biotic potential, which is the maximum rate of increase per individual for nay population that is growing under ideal conditions, will eventually lead to the carry capacity of a population. The carry capacity is the maximum number of individuals of a population that a given environment can sustain indefinitely. If the biotic potential reaches 100%, it will fulfill the entire carrying capacity.
b. Biological Magnification & Trophic Level
Biological magnification occurs in trophic levels. The concentration of a slowly degradable or non-degradable substance in body tissues increases as it passes along food chains. If a primary producer has a concentration of x1 pollution, that number will consistently increase as it is eaten by a primary consumer, increasing to x2. This increase remains constant as secondary and tertiary consumers eat their prey in the lower trophic level.
c. Detritivores & Autotrophs
Detritivores are organisms that obtain their energy by consuming dead plants and animals. Autotrophs are primary producers who convert the sunlights energy into chemical energy. The autotrophs are the first trophic level because they are the source of all chemical energy for other organisms to consume. Detritivores are the last trophic level because they consume all the energy that was consumed by the other trophic levels.
d. Mitochondria & Greenhouse Gases
Wavelengths in rays from the sun warm the surface of the Earth. The surface radiates heat, infrared wavelengths, to the atmosphere. Greenhouse gases and water vapor absorb some infrared energy and radiate a portion of it toward back toward Earth. Increased concentrations of greenhouse gases, for example, the increases concentration of carbon dioxide in the winter when photosynthesis rates decrease but aerobic respiration in the mitochondria still occurs, trap more heat near Earth's surface causing the temperature to rise.
III. Few Essentials
a. 45.4 Outline
I. Limits on the Growth of Populations
A. Density-Dependent Limiting Factors
1. environmental circumstances keep population from fulfilling biotic potential
2. limiting factors affect population growth
B. Carry Capacity and Logistic Growth
1. sustainable supply of resources will determine population growth
2. pattern of logistic growth can show the effects of carrying capacity
3. when overcrowding occurs: density-dependent controls
C. Density-Independent Limiting Factors
1. can cause more deaths or fewer births
2. regardless of population density
b. 3 Survivorship Curves
Type 1: reflect high survivorship until fairly later in life, then a large increase in deaths.
ie: large mammals, such as elephants, have one or a few large-bodied offspring at a time, then engage in an extended parental care
Type 2: reflect a fairly constant death rate at all ages
ie: organisms just as likely to be killed of die of disease at any age, such as lizards
Type 3: reflect a death rate that is highest early in life
ie: species that produce many small offspring and do little parenting, such as sea stars
c. Age Structure Diagrams
1. A population undergoing negative growth: The base of the diagram representing pre-reproductive years is much smaller than the top of the diagram representing post-reproductive years. The maximum population growth is at the early post-reproductive years, around age 45.
2. A population with nearly no growth: The base of the diagram stays almost the same width all the way up towards the start of the post-reproductive years. It starts to decline after that showing a consistent death rate in those ages.
3. A population growing rapidly: The base of the diagram is way more than twice the size of the rest of the diagram. It consistently decreases its width towards the top, resembling almost nothing at the highest ages.
4. A population growing slowly: It shows a steady decrease in width going from the base of the diagram to the top. There is a very small difference between the number of pre-reproductive year people than post-reproductive year people.
d. The Nitrogen Cycle
Nitrogen in abundant in the atmosphere in its gaseous form of N2. This form of nitrogen is useless to plants and animals, so it needs to be converted to a solid form. Nitrogen fixing bacteria convert the N2 into NH4. Nitrifying bacteria convert the NH4 to NO2, nitrites, and NO3, nitrates. Plants can then absorb the NO3 and pass it to animals who consume the plants. After the animals and plants die, detritivores break down their matter and release the nitrogen back to the soil through ammonification.
II. Connections
a. Carrying Capacity & Biotic Potential
The biotic potential, which is the maximum rate of increase per individual for nay population that is growing under ideal conditions, will eventually lead to the carry capacity of a population. The carry capacity is the maximum number of individuals of a population that a given environment can sustain indefinitely. If the biotic potential reaches 100%, it will fulfill the entire carrying capacity.
b. Biological Magnification & Trophic Level
Biological magnification occurs in trophic levels. The concentration of a slowly degradable or non-degradable substance in body tissues increases as it passes along food chains. If a primary producer has a concentration of x1 pollution, that number will consistently increase as it is eaten by a primary consumer, increasing to x2. This increase remains constant as secondary and tertiary consumers eat their prey in the lower trophic level.
c. Detritivores & Autotrophs
Detritivores are organisms that obtain their energy by consuming dead plants and animals. Autotrophs are primary producers who convert the sunlights energy into chemical energy. The autotrophs are the first trophic level because they are the source of all chemical energy for other organisms to consume. Detritivores are the last trophic level because they consume all the energy that was consumed by the other trophic levels.
d. Mitochondria & Greenhouse Gases
Wavelengths in rays from the sun warm the surface of the Earth. The surface radiates heat, infrared wavelengths, to the atmosphere. Greenhouse gases and water vapor absorb some infrared energy and radiate a portion of it toward back toward Earth. Increased concentrations of greenhouse gases, for example, the increases concentration of carbon dioxide in the winter when photosynthesis rates decrease but aerobic respiration in the mitochondria still occurs, trap more heat near Earth's surface causing the temperature to rise.
III. Few Essentials
a. 45.4 Outline
I. Limits on the Growth of Populations
A. Density-Dependent Limiting Factors
1. environmental circumstances keep population from fulfilling biotic potential
2. limiting factors affect population growth
B. Carry Capacity and Logistic Growth
1. sustainable supply of resources will determine population growth
2. pattern of logistic growth can show the effects of carrying capacity
3. when overcrowding occurs: density-dependent controls
C. Density-Independent Limiting Factors
1. can cause more deaths or fewer births
2. regardless of population density
b. 3 Survivorship Curves
Type 1: reflect high survivorship until fairly later in life, then a large increase in deaths.
ie: large mammals, such as elephants, have one or a few large-bodied offspring at a time, then engage in an extended parental care
Type 2: reflect a fairly constant death rate at all ages
ie: organisms just as likely to be killed of die of disease at any age, such as lizards
Type 3: reflect a death rate that is highest early in life
ie: species that produce many small offspring and do little parenting, such as sea stars
c. Age Structure Diagrams
1. A population undergoing negative growth: The base of the diagram representing pre-reproductive years is much smaller than the top of the diagram representing post-reproductive years. The maximum population growth is at the early post-reproductive years, around age 45.
2. A population with nearly no growth: The base of the diagram stays almost the same width all the way up towards the start of the post-reproductive years. It starts to decline after that showing a consistent death rate in those ages.
3. A population growing rapidly: The base of the diagram is way more than twice the size of the rest of the diagram. It consistently decreases its width towards the top, resembling almost nothing at the highest ages.
4. A population growing slowly: It shows a steady decrease in width going from the base of the diagram to the top. There is a very small difference between the number of pre-reproductive year people than post-reproductive year people.
d. The Nitrogen Cycle
Nitrogen in abundant in the atmosphere in its gaseous form of N2. This form of nitrogen is useless to plants and animals, so it needs to be converted to a solid form. Nitrogen fixing bacteria convert the N2 into NH4. Nitrifying bacteria convert the NH4 to NO2, nitrites, and NO3, nitrates. Plants can then absorb the NO3 and pass it to animals who consume the plants. After the animals and plants die, detritivores break down their matter and release the nitrogen back to the soil through ammonification.
Saturday, January 15, 2011
Ch. 46 & 49
Ecology 1
2. Connections
2. Connections
a. Co-evolution & Commensalism
Co-evolution refers to species that evolve jointly when their interaction produces selection pressure on each other. A gene mutation may occur causing a prey to increase defense mechanisms, or a predator to catch its prey more efficient. Commensalism is the interaction between two species, where one benefits and one is not affected. If co-evolution occurs, it could disrupt the commensalism between the species, causing the neutral one to become harmed or to benefit.
b. Mimicry & Aposematic Coloration
In mimicry, a mimic organism resembles a model organism very closely in form and behavior. An organism develops aposematic coloration after eating its prey and associating its appearance to the toxins and foul taste it receives. An organism can develop aposematic coloration on either a mimic or a model involved in mimicry and become now confused on what it is supposed to eat. Its prey may be the model organism, but if the mimic is eaten, the predator will not eat its real prey because it has developed an aposematic coloration on it.
c. Altruism & Allele
Altruism is a self-sacrificing behavior, where an individual helps a population by reducing its own chance of producing offspring. An allele is a molecular form of a gene normally developing from a mutation. An organism who experiences altruism may gain an allele that reduces its reproduction chances.
d. Species & Population & Niche
A niche is the sum of its activities and interactions a species acquires to use the resources it must have to survive and reproduce. The niche of a species and how well the species can adapt its niche to work with its environment will determine how will it will survive among its population.
3. Few Essentials
a. Examples of the following concepts and interactions
1. Commensalism: The sparrow, a small bird, builds its nest under the nest of the osprey. The osprey is a larger bird that protects the sparrow's nest without knowing its there.
2. Mutualism: Lichen is a half plant half fungus. The plant provides food for the fungus, while the fungus provides protection from radiation and water absorption.
3. Parasitism: Tapeworms enter the human body and live in the intestines. It feeds off of the nutrients the human eats, causing the human to keep eating but not gain any nutritional support. The human dies from malnutrition.
4. Resource Partitioning: The bristly foxtail and the smartweed plant live in the same field, but need to gain the same requirements, such as sunlight, water, and minerals. The bristly foxtail has a shallow root system, allowing it to grow where moisture shifts daily. The smartweed has a taproot system, allowing it to grow where soil is perpetually moist.
5. Predator-prey Co-evolution: The snowshoe hare, due to its predation, constantly looks over its shoulder with alert and in fear.
6. Camouflage: A caterpillar can look like birds droppings if it has special color patterns.
7. Mimicry: Beetles and flies can mimic the appearance of the model yellowjacket to avoid being eaten.
8. Aposematic Coloration: A bird can develop aposematic coloration after eating a certain orange-and-black butterfly. The bird will associate the butterfly's color to the toxins and foul taste it had.
9. Pioneer Species: Douglas firs started to grow in the Cascade area at the bottom of the Mount St. Helen volcano a decade after the volcano erupted.
10. Keystone Species: Periwinkles, algae-eating snails, help maintain the number of algal species in tidepools, but reduce it on exposed rock surfaces.
11. Instinctive Behavior: A human baby imitates the facial expressions of adults out of experience before learning them.
12. Imprinting: Baby geese follow their mom around during their short, sensitive period after hatching.
13. Altruism: Zebras are eaten by lions to help the lion population grow.
14. Chemical Communication: The honeybee sends chemical alarms to call action against potential threats.
15. Tactile Communication: When a honeybee finds a source of pollen or nectar, it performs a dance, keeping close contact to the other bees to signal to them the information about about the food source.
16. Courtship ritual/display: King penguins tilt their necks towards each other as a sign of affection.
d. Species & Population & Niche
A niche is the sum of its activities and interactions a species acquires to use the resources it must have to survive and reproduce. The niche of a species and how well the species can adapt its niche to work with its environment will determine how will it will survive among its population.
3. Few Essentials
a. Examples of the following concepts and interactions
1. Commensalism: The sparrow, a small bird, builds its nest under the nest of the osprey. The osprey is a larger bird that protects the sparrow's nest without knowing its there.
2. Mutualism: Lichen is a half plant half fungus. The plant provides food for the fungus, while the fungus provides protection from radiation and water absorption.
3. Parasitism: Tapeworms enter the human body and live in the intestines. It feeds off of the nutrients the human eats, causing the human to keep eating but not gain any nutritional support. The human dies from malnutrition.
4. Resource Partitioning: The bristly foxtail and the smartweed plant live in the same field, but need to gain the same requirements, such as sunlight, water, and minerals. The bristly foxtail has a shallow root system, allowing it to grow where moisture shifts daily. The smartweed has a taproot system, allowing it to grow where soil is perpetually moist.
5. Predator-prey Co-evolution: The snowshoe hare, due to its predation, constantly looks over its shoulder with alert and in fear.
6. Camouflage: A caterpillar can look like birds droppings if it has special color patterns.
7. Mimicry: Beetles and flies can mimic the appearance of the model yellowjacket to avoid being eaten.
8. Aposematic Coloration: A bird can develop aposematic coloration after eating a certain orange-and-black butterfly. The bird will associate the butterfly's color to the toxins and foul taste it had.
9. Pioneer Species: Douglas firs started to grow in the Cascade area at the bottom of the Mount St. Helen volcano a decade after the volcano erupted.
10. Keystone Species: Periwinkles, algae-eating snails, help maintain the number of algal species in tidepools, but reduce it on exposed rock surfaces.
11. Instinctive Behavior: A human baby imitates the facial expressions of adults out of experience before learning them.
12. Imprinting: Baby geese follow their mom around during their short, sensitive period after hatching.
13. Altruism: Zebras are eaten by lions to help the lion population grow.
14. Chemical Communication: The honeybee sends chemical alarms to call action against potential threats.
15. Tactile Communication: When a honeybee finds a source of pollen or nectar, it performs a dance, keeping close contact to the other bees to signal to them the information about about the food source.
16. Courtship ritual/display: King penguins tilt their necks towards each other as a sign of affection.
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