Organisms inherit genetic information in a variety of ways that result in continuity of structure and function between parents and offspring.
All living things have a set of instructions (genes) that determine their characteristics.
These instructions are passed down from parent to offspring during reproduction.
These instructions can be changed through recombination, mutations and genetic engineering.
The code of the directions is in the DNA molecules. It must be copied accurately in order to contain the correct information to make proteins that the organism needs and will be expressed as traits.
Genes are inherited BUT their EXPRESSION can be effected by the ENVIRONMENT.
Heredity is the passage of coded instructions for specific traits that is passed on to offspring, from one generation to the next.
DNA makes up genes (a section of DNA with specific information), genes are found on chromosomes and chromosomes are in the nucleus.
Asexual reproduction does not have variations (differences) since all genes came from one parent cell. Daughter cells are identical to parent cell.
Sexual reproduction new individual receives half of the genetic information from its mother (egg) and half from father (sperm).
Sexual reproduction leads to offspring that resemble but are not identical to the parents.
DNA carries the coded information for inheritance. Traits are coded for the by the arrangement of four bases in DNA - A,T,C,G.
The arrangement of bases determines the structure and folding of the protein they produce.
For reproduction, coded instructions must be copied by a process called replication.
Genes are segments of DNA and any change in a base (A,T,C,G) results in a mutation.
Offspring resemble their parents because they inherit similar genes which code for similar proteins which produce similar structures and functions in the cells.
All cells in the body have the same chromosomes! In different cells different genes are turned on and off so the cell can perform its job.
Review: Mitosis, Cell Regulation, Cancer, Stem Cells
Every organism requires a set of coded instructions for specifying its traits. For offspring
to resemble their parents, there must be a reliable way to transfer information
from one generation to the next. Heredity is the passage of these instructions from one
generation to another.
Hereditary information is contained in genes, located in the chromosomes of each
cell. An inherited trait of an individual can be determined by one or by many genes, and
a single gene can influence more than one trait. A human cell contains many thousands
of different genes in its nucleus.
Offspring resemble their parents because they inherit similar genes that code for
the production of proteins that form similar structures and perform similar functions.
Some organisms reproduce asexually with all the genetic information coming from
one parent. Asexual reproduction is the process of mitosis. It produces 2 identical daughter cells which are exact copies of each other and the original cell. It is used as reproduction for single celled organisms and growth and repair in multicelled organisms.
Stem cells are cells that have not been given a job yet - all the DNA is still turned on. They can become any type of cell at which point the DNA not needed for the job will be turned off. Many possible applications for disease treatment.
Cancer is the uncontrolled mitosis of cells.
The stages of mitosis and the main activity that takes place in each: I - PMAT - Cytokinesis, replication is the copying of the DNA in a cell which ensures that the proper number of chromosomes will be passed on to the next generation of cells.
Hereditary information stored on genes which are on chromosomes which are in the nucleus which is in the cell.
Examples of mitosis: binary fission, budding (yeast and hydra), vegetative growth
Review materials for Mitosis/Meiosis/Inheritance of traits Test
Organisms inherit genetic information in a variety of ways that result in continuity of structure and function between parents and offspring.
All living things have a set of instructions (genes) that determine their characteristics.
These instructions are passed down from parent to offspring during reproduction.
These instructions can be changed through recombination, mutations and genetic engineering.
The code of the directions is in the DNA molecules. It must be copied accurately in order to contain the correct information to make proteins that the organism needs and will be expressed as traits.
Genes are inherited BUT their EXPRESSION can be effected by the ENVIRONMENT.
Heredity is the passage of coded instructions for specific traits that is passed on to offspring, from one generation to the next.
DNA makes up genes (a section of DNA with specific information), genes are found on chromosomes and chromosomes are in the nucleus.
Asexual reproduction does not have variations (differences) since all genes came from one parent cell. Daughter cells are identical to parent cell.
Sexual reproduction new individual receives half of the genetic information from its mother (egg) and half from father (sperm).
Sexual reproduction leads to offspring that resemble but are not identical to the parents.
DNA carries the coded information for inheritance. Traits are coded for the by the arrangement of four bases in DNA - A,T,C,G.
The arrangement of bases determines the structure and folding of the protein they produce.
For reproduction, coded instructions must be copied by a process called replication.
Genes are segments of DNA and any change in a base (A,T,C,G) results in a mutation.
Offspring resemble their parents because they inherit similar genes which code for similar proteins which produce similar structures and functions in the cells.
All cells in the body have the same chromosomes! In different cells different genes are turned on and off so the cell can perform its job.
Human Impact on the environment:
Earth has finite resources - increased consumption stresses natural processes that may renew these resources, may deplete the resources that cannot be renewed
Natural ecosystems - maintain the quality of the atmosphere, generate soils, control the water cycle, remove wastes, maintain the energy flow and recycle nutrients.
Humans can alter the equilibrium in ecosystems as a result of: population growth, consumption and technology. This may be caused by: direct harvesting, pollution, atmospheric change
If ecosystems are degraded: loss of diversity may occur, land use decreases space and resources for other species
Humans alter ecosystems by adding or removing species
Increased industrialization increases demand for energy and resources included fossil and nuclear fuels.
Humans must create proposals which involve new technology and make decisions assessing risks, costs, benefits and trade-offs.
One generations decisions may provide or limit possibilities for the next generation.
Fossil fuels: are not renewable, alternative sources of energy must be discovered and utilized - wind, solar, decreased use of automobiles - more efficient cars-
To produce and use energy
perform respiration, digestion, excretion, synthesis, circulation, reproduction,
adaptation, maintain homeostasis
Scientific Method:
Steps: Question, research, hypothesis, experiment, data collection/analysis,
conclusion, recommendations for further study
Hypothesis: Makes a prediction about the effect of an independent variable
Independent variable: the variable the experimenter decides to change
Dependent variable: the change that is measured as a result of the independent
variable
Controlled experiment: and experiment where there are at least two test groups:
Control group - you do not change the group, you use it for comparison
it does not get the independent variable
Experimental group - it is treated with the independent variable
Circulatory System
Circulation: This system moves materials around in the body. It has two types of fluid - blood and lymph.
The system consists of the:
Heart - for pumping
*right side receives blood high in carbon dioxide from the body and pumps it to the lungs
*left side receives blood from the lungs which is high in oxygen and pumps it to the body
Blood vessels - for moving the blood around in a closed system
* arteries take blood away from the heart
-they are thick and muscular
-they have a pulse
-they carry blood high in oxygen
*capillaries
-they are only one cell thick
-they have very thin walls to allow diffusion to take place
-they are the only place in the circulatory system where exchange of materials takes place
-they drop off oxygen and nutrients and pick up carbon dioxide and wastes
*veins return blood to the heart
-they have thinner walls than arteries
-they do not have any blood pressure
-they have valves to prevent the blood from flowing backwards
-they carry blood high in carbon dioxide
Genetic engineering and Evolution:
Genetic engineering
Man has worked to change organisms
Selective breeding: humans choose traits in cultivated plants and domestic animals they desire and cross-breed organisms with desired traits
Genetic Engineering or Recombinant DNA:
1 - Humans choose traits from organisms, identify the gene that produces these traits and insert the gene into the new organism - can be done across species. Requires the use of biotechnology
2 - New varieties of farm plants and animals have been engineered by moving genes between species to produce new characteristics
3 - In order to move and relocate genes enzymes are used to cut, copy and move segments of DNA. '
4 - When these genes are inserted into new organisms the proteins may be expressed by the new organism - like bacteria and human insulin
5 - Genes can be altered by adding, deleting or inserting DNA segments. Every cell that develops from this cell will express this new altered gene.
Technology makes it possible to have new fields of health care:
1 - finding genes that have mutations that can cause disease will aid in the development of preventative measures to fight disease
2 - Hormones and enzymes produced from genetically engineered organisms may reduce the cost and side effects of replacing missing body chemicals (insulin, human growth hormone)
Evolution
Evolution states that present day organisms came from earlier, distinctly different species
New traits come from genetic recombination (meiosis, crossing over, sperm and egg union) and from mutations in sex cells
Mutations are:
random events, can be caused by radiation and chemicals, if in sex cells will be passed on to offspring
Natural selection and the evolutionary consequences explain:
*the fossil record
*molecular and structural similarities observed among the diverse species of living organisms
Species evolve over time, evolution occurs due to:
*the potential for a species to increase its numbers
*the genetic variability of offspring due to mutation and recombination of genes
*finite supply of the resources required for life
*the selection by the environment of those organisms with the best adaptations to survive and leave offspring.
Advantageous traits:
*give organisms an better change at surviving and reproduction
*offspring inherit the new trait and have increased survival rates
*the rate of individuals with the new trait will increase
Variations in species:
species with variations will have an increased chance of survival in changed environment conditions
Behaviors of species:
*behaviors are inherited and passed on to offspring.
Evolutionary trees - cladograms
evolution does not always move in one set direction
Changes look like the branches of a tree - some continue to grow with no change, some die out all together and others branch many time giving rise to more complex organisms
Extinction
occurs when the environment changes and the adaptive characteristics of a species are not enough to allow it to survive
fossil records show that many organisms that lived long ago are extinct
most species that have lived on the Earth no longer exist
Review for Evolution test
Why do we have such a wide variety of organisms today?
1 - life started out as simpler, less complex organisms
Most organisms that were are earth are now extinct.
2 - mutations and genetic variations produced organisms more and more complex
3 - Those with the best adaptations survived, reproduced and increased the occurrence of their traits
4 - Classification schemes have been used to identify organisms
* Most common method of classification created by Linnaeus
*Uses binomial nomenclature - two names: genus and species
example: Canis lupus
5 - Variations arise from either mutations or genetic variations
#mutations - changes in the DNA due to mutagenic agents
*radiation, UV rays, benzene, asbestos, formaldehyde, tobacco
*mutations are random and usually neutral or harmful
genetic variations - from sexual reproduction
*recombinations of genes during fertilization, crossing over of genes during meiosis
Darwin's Theory of Evolution
1 - Can also be called the theory of Natural Selection
2 - Three parts to his theory:
*organisms have variations that can give them advantages over other members of their species
*organisms overproduce in order that some of the species will survive
*there is competition for finite resources and the best adapted will survive
If you have an advantageous trait that others in the species do not have you will get more food, have more mates, reproduce more and increase the occurance of the trait.
Evidence for evolution
Fossil Record - shows organisms as they have changed,
- an actual visual record of changes
- found in sedimentary rock
- oldest organisms on the bottom in undisturbed layers
Comparative Studies - comparative anatomy, embryology, biochemistry, genetics
anatomy - look at structures like bones to see if organisms had a common ancestor
embryos - look at embryos at early stages to see if similarities indicate a common ancestor
biochemistry - look at similarities of proteins, hemoglobin, other chemical found in organisms to see how similar they are - indications of a common ancestor
genetics -look at DNA to see similarities or differences in base order to look for common ancestor
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Genetics, Protein Synthesis and Replication
Organisms inherit genetic information in a variety of ways that result in continuity of structure and function between parents and offspring.
Genes - a set of instruction that determines characteristics.
Pass from parent to offspring during reproduction.
DNA - the molecular basis for inheritance
Genes - can be changed through *recombination, *mutation and *genetic engineering.
Inheritance code - DNA molecules
Replication - code must be copied before it can be inherited
Code is used to produce proteins that determine traits
Genes can be inherited - traits can be affected by the environment
Heredity - passing on of coded instructions for traits
Asexual reproduction - all genes from one parent
offspring identical to each other and parents
Sexual reproduction - half genes from each parent
offspring resemble but are not identical to parents
Nucleus - stores and uses DNA code to produce proteins
Genes - segments of DNA, any change in DNA produces a mutation
Mutations - passed on if present in gametes (sperm or eggs) only
Body cells - have same DNA in each cell, but only genes turned on are ones used to produce proteins needed for the function of the cell
Below this line is review information for later in the year
Review for Human Systems test
RB pages 72-95
Respiration: Remove carbon dioxide and take in oxygen
Air flows from oral cavity/mouth/nose to pharynx past epiglottis through trachea into bronchi to the bronchioles to the alveoli/air sacs.
In the alveoli the oxygen moves into the capillaries by diffusion and the carbon dioxide moves into the air sac from the capillaries by diffusion.
The diaphragm is directly under the lungs and makes respiration possible. When the diaphragm contracts it pulls down which expands the lungs. The air rushes in to fill the new space created. When the diaphragm relaxes it pushes up on the lungs which pushes the air out.
External respiration provides the oxygen that cell use in cellular respiration to produce ATP for
Nervous system - maintains homeostasis together with the endocrine system
Functional unit is the neuron:
Signal or stimulus is picked up by the dendrites, passes through the cell body and the axon and is passed on to the next neuron by the neurotransmitters.
The second neuron must have the correct shape receptors to match the neurotransmitter molecules or the message will not be passed on.
They use electrical energy to pass the message along the neuron and chemical energy to transfer the energy to the next neuron.
The nervous system has two parts:
Central nervous system - the brain and the spinal cord.
Peripheral nervous system - the neurons in the rest of the body
A reflex - an automatic response to a stimulus that involves a receptor neuron, an interneuron and a motor neuron.
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Review Materials for DNA Replication/Protein Synthesis Test/Quiz
Organisms inherit genetic information in a variety of ways that resutl in continuity of structure and function between offspring and parents.
DNA must be accurately replicated (copied) in order to pass on traits through heredity.
DNA must be accurately copied to produce identical cells during mitosis.
DNA is a large molecule formed from subunits arranged in a sequence with bases of four kinds - A, T, C, G.
These subunits determine the chemical and strutural properties of substances produced from the genes (the string of moleculer bases with directions to make proteins) and replicated by means of a template.
Cells both store and use the coded information. It synthesizes thousands of proteins needed by the cell.
Nucleotides make up DNA which make up genes which are found on chromosomes in the nucleus of a eukaryotic cell.
A mistake in a base in the strand of DNA may lead to a change in the amino acid which may lead to a protein which is not able to function properly.
Proteins are made up of strands of amino acids joined by peptide bonds. The order of the amino acids comes from the DNA and determines the folding, shape and function of the protein.
20 amino acids are needed to produce all the proteins needed by organisms.
All cells in an organism have the same DNA - even though they have different jobs and may look and act differently. Only parts of the DNA,needed for the job of the cell, are turned on in each cell.
Directions for protein synthesis are sent to the ribosome by mRNA.
mRNA is read in groups of 3 bases - codons - by the ribosome.
tRNA molecules match up to the codons with anticodons and gather amino acids from the cytoplasm.
Amino acids are defined by 3 bases.
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Review materials for Mitosis/Meiosis/Inheritance of traits Test
Wednesday or Thursday 2/13 0r 2/14
Wednesday or Thursday 2/13 0r 2/14