2010 Biology STAAR Bootcamp
Welcome to your 2012 Biology STAAR bootcamp! Please start at the station of the number that you received when you walked in. The reason you are here this morning is to get ready for your STAAR test on May 9th, 2012. This packet should be used as a study guide to help you prepare for your upcoming test. You can use it as a reference as you go to each station. Take notes and star anything you may be unsure of and would like to discuss with your biology teacher during class. We all here to help so please don’t be afraid to ask questions!!!
Station 1: Cell Structure and Function
Biological Organization
Atomsà biological moleculesà cellsà tissuesà organsà organ systemsà organismà populationà communityà ecosystemà biosphere
Atoms of different elements (such as carbon, hydrogen, oxygen, nitrogen and phosphorus), join together to form: Biological Molecules. Biological molecules join together to form cells. The cell is the basic unit of living organism. Cells join together to form Tissues. Tissues join together to form organs. Organs join together to form Systems. Systems join together to form an organism.
Organisms join together to form populations.
Populations join together to form a community. A community is several interacting populations that live in a common environment. Communities join together to form an Ecosystem. An ecosystem is the living and nonliving parts of an environment. Ecosystems join together to form the biosphere. The biosphere is the portion of the earth that supports life.
Biomolecules- Large organic molecules that make up living things. Organic molecules are CARBON based.
4 types of biomolecules:
Carbohydrates – made of carbon, hydrogen and oxygen Living organisms use carbohydrates such as ______and starches as a source of energy.
Plants store energy in the form of STARCH. Starch is a carbohydrate. Glucose and fructose are simple sugars, the smallest units of a carbohydrate.
Lipids- Store energy and make up cell membranes
1. Fats, oils and waxes
2. Phospholipids - lipids that form cell membranes.
Proteins- Made up of amino acids linked together by peptide bonds. Proteins have many important functions.
Example: Hemoglobin is a protein in red blood cells that carries oxygen.
There are 20 common amino acids that make up proteins. You don’t need to know the names of the amino acids, just know that they are joined together to make proteins.
Proteins are needed for:
• Growth
• Repair
• Moving substances in and out of the cell
• Regulating chemical reactions
• Enzymes are usually proteins. They speed up the rate of chemical reactions. Enzymes are found in all living cells.
Nucleic acids - DNA and RNA-They store and transmit genetic (hereditary) information and are involved in making proteins. Animals get necessary biological molecules, or the components of biomolecules, from the foods they eat.
Plant and Animal Cells-
Plant cells have:
· A cell wall made of cellulose which gives the cell structure and support.
· Plant cells have organelles called chloroplasts that contain chlorophyll for photosynthesis.
· The chlorophyll in the chloroplasts captures solar energy for photosynthesis.
Both plant and animal cells have:
· Mitochondria for cellular respiration (harnessing energy)
· A plasma membrane that surrounds the cell.
· A nucleus that contains the DNA. DNA has the genetic code for making all the proteins in a cell.
Other cell organelles include:
· Lysosome – organelle that carries out the digestive processes in the cell.
· Rough Endoplasmic Reticulum – has ribosomes, makes proteins.
· Smooth Endoplasmic Reticulum – detoxifies and makes lipids. Has no attached ribosomes.
· Golgi apparatus – sorts and distributes proteins.
· Ribosomes- where proteins are made.
Cell Division-
Bacteria divide by binary fission. Bacteria do not have a nucleus.
Mitosis - Cell division in cells that have a nucleus (eukaryotes).
Mitosis produces cells that are identical to the parent cell.
· If the parent cell has 46 chromosomes… the daughter cells will have 46 chromosomes.
Meiosis- the production of sex cells or gametes. 4 new cells are produced with half the number of chromosomes.
· If the parent cell has 46 chromosomes, each of the daughter cells will have 23. Meiosis produces eggs and sperm.
· Egg cells and sperm cells must have half the number of chromosomes as the parent cell… so that the zygote has the proper # of chromosomes. A zygote is a fertilized egg.
The Plasma Membrane and Homeostasis
The plasma membrane (also called the cell membrane) is a membrane made up of phospholipid molecules. It serves as a boundary around the cell.
The plasma membrane is semi-permeable. It allows only certain things into and out of the cell. It helps to maintain the homeostasis of the cell.
Homeostasis is maintaining a balance, or regulating internal conditions in an organism.
· Ex. All living organisms must have the proper balance of temperature, water, energy, etc.
Cell Transport-
Passive- When substances pass across the membrane without requiring cellular energy.
· Osmosis is the diffusion of water across a membrane from an area of high water concentration to an area of low water concentration.
· The membrane is usually the plasma membrane.
· Osmosis does not require cellular energy, so it is a form of passive transport.
Active- When cell energy is required for substances to pass across the plasma membrane.
Cell Respiration
Cell Respiration-The process of transferring stored energy from glucose to energy for the cell (ATP).
When animals eat food their digestive systems break it down into molecules like glucose.
One minor problem! Glucose is not used directly for energy.
ATP is the molecule that the cell can directly use for energy.
To make ATP in the mitochondria the cell needs: glucose and oxygen.
This is the reason we breathe! Our cells must have oxygen to make ATP (energy) for the cell.
What are the products of cellular respiration?
· ATP (energy for the cell)
· Carbon dioxide
· Water
(You exhale carbon dioxide because it’s a waste product of the cell.)
The reaction for cellular respiration is:
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
Glucose + Oxygen carbon dioxide + water + energy
Photosynthesis
Photosynthesis is the process by which plants make their own food (glucose).
The cell organelle where photosynthesis takes place is called the chloroplast.
Photosynthesis builds glucose molecules. The formula for glucose is- C6H12O6
For photosynthesis to take place the plant cell must have: sunlight, carbon dioxide, and water.
The formula for photosynthesis is:
6CO2 + 6H2O + sunlight C6H12O6 + 6O2
Carbon Dioxide + water + energy glucose + oxygen
Compare the formulas for photosynthesis and cellular respiration.
Photosynthesis- 6CO2 + 6H2O + sunlight C6H12O6 + 6O2
Cellular respiration- C6H12O6 + 6O2 6CO2 + 6H2O + ATP
They are the opposite!
Viruses- are made up of a nucleic acid (DNA or RNA) in protein coat. They are considered to be non-living because they don’t respire, grow, metabolize nutrients or develop. They can only reproduce by invading a cell.
Bacteriophage- a virus that attacks bacterial cells.
Before the virus can replicate, it must attach to and enter a host cell. The virus is shaped to lock on to a receptor site of a specific host cell.
The virus injects its nucleic acid (DNA or RNA) into the host cell. The host cell makes copies of the viral genes and proteins and the new viruses are assembled.
The new viruses burst out of the host cell, killing it. They can now attack and kill other host cells.
Not all viruses immediately kill the cells they infect. After the viral nucleic acid is injected into the host cell, it may remain inactive for a period of time.
Viruses cause diseases such as smallpox, AIDS, influenza (flu), warts and the common cold.
The HIV virus (which causes AIDS) attacks a type of white blood cell called helper T cells. Helper T cells help the body fight infection.
Viruses have a specific receptor sites that will only fit a certain type of cell.
Antibiotics are used to kill bacterial infections, but will not kill viral infections.
Vaccines are made of a weaker or similar virus that triggers the body to make antibodies to fight off the viral infection.
Station 2: Mechanisms of Genetics
DNA- (deoxyribonucleic acid) is found in the nucleus of cells. It contains the hereditary information for making proteins.
DNA is made up of building blocks called nucleotides. Each nucleotide is made up of
1. Sugar (deoxyribose)
2. Phosphate
3. One of the following nitrogen bases: adenine, thymine, cytosine, or guanine
The nucleotides are bonded in a specific way.
Adenine always bonds with Thymine.
Cytosine bonds with Guanine.
The shape of DNA is described as a double helix or a twisted ladder.
The sequence of the nitrogen bases determines the traits of an organism.
DNA is the molecule that determines an organism’s eye color, body structure and cellular enzyme production.
The components that make up the genetic code are common to all organisms.
Terms that relate to DNA: genes, chromatin, chromatid, chromosomes, genetic material, allele, deoxyribonucleic acid, genome, and nucleic acid.
DNA Replication
Before the cell can divide, the DNA must replicate or make a copy of itself.
The sides of the DNA molecule separate.
New nucleotides bond with the existing nucleotides.
Two identical strands of DNA are formed.
RNA- Ribonucleic Acid
There are 3 types of RNA involved in making proteins:
mRNA = messenger RNA tRNA = transfer RNA rRNA = ribosomal RNA
mRNA is a copy of the DNA code.
tRNA carries amino acids to the ribosomes to assemble proteins.
rRNA makes up the ribosomes.
RNA is different from DNA in the following ways:
1. RNA is single stranded
2. RNA has the sugar ribose
3. The nitrogen bases in RNA are adenine, uracil, cytosine, and guanine. RNA has uracil instead of thymine
Adenine bonds with uracil. A-U
Cytosine bonds with Guanine. C-G
A sequence of 3 nucleotides of mRNA is called a codon. Each codon codes for an amino acid.
Example: The codon CCA codes for the amino acid proline
tRNA has an anticodon that compliments the mRNA codon.
Protein Synthesis
DNA has the instructions for making all the proteins needed by the cell. DNA is found in the nucleus of the cell.
(DNA makes up the chromosomes)
Protein synthesis is the process by which the cell makes proteins using the DNA code.
Protein synthesis occurs in two steps:
1. transcription – the DNA code is copied to make mRNA.
· The hydrogen bonds between the DNA molecule separate.
· mRNA nucleotides join one side of the DNA strand to make a copy.
· mRNA leaves the nucleus to take the copied DNA code to a ribosome.
2. Translation – tRNA brings amino acids to the ribosomes to make a protein.
Genetics - the study of heredity.
Humans have 23 pairs of chromosomes. Segments of chromosomes that code for specific traits are called genes. Genes come in pairs.
Genes control traits. Chromosomes are made up of DNA.
You received one set of chromosomes from your mother (23) and one set from your father (23) to make 23 pairs or 46 chromosomes.
Genes exist in alternative forms called alleles. Alleles are located on chromosome pairs.
Many gene pairs follow Mendel’s law of dominance and recessiveness.
A dominant gene will override or show up over a recessive gene.
A capital letter is used to represent a dominant gene and a lower case letter is used to represent a recessive gene.
For example, free earlobes (unattached) is dominant over attached earlobes.
The phenotype of an organism is the physical appearance, or what you see.
The genotype is the actual genetic makeup.
If both genes are the same, the individual is homozygous.
If the two genes are different, the individual is heterozygous for that trait.
The genetic makeup of organisms can be studied by: DNA fingerprinting, genetic modifications, and chromosomal analysis.
Punnett Squares- can be used to predict the possible genotypes and phenotypes of the offspring.
Before setting up your Punnett square you must first determine what genes can be in the parent’s gametes (sex cells).
During meiosis, the formation of sex cells, the gene pairs will separate and the gametes will receive one of each.
The allele for widow’s peak (W) is dominant. The gene for no widow’s peak (w) is recessive.
One parent is heterozygous for widow’s peak. The other parent has no widow’s peak. What are the possible genotypes of their offspring?
Heterozygous parent = Ww
Parent with no widow’s peak = ww
Ww x ww
Put the possible genotypes of one parent across the top of the Punnett square and the possible gametes of the other parent down the side.
Fill in the squares.
Set up and complete the Punnett square for this cross in the space below.
EeWW x eeWw
Genetics-Patterns of Inheritance
Genetic traits are not always dominant or recessive.
Some traits follow different patterns of inheritance.
Incomplete Dominance
Two different genes, when paired, blend together and produce a 3rd phenotype.
Red snapdragons and white snapdragons produce pink snapdragons.
Codominance – both alleles are expressed.
When a certain variety of black chicken is crossed with a white chicken, all of the offspring are checkered. Both feather colors are equally expressed.
Sex- Linked Traits
· Traits are found on the X sex chromosome.
· The Y chromosome does not have a gene for the trait.
· Males only have to inherit 1 recessive gene; more males will have the condition.
· Example is hemophilia (h) a recessive blood clotting disorder. The normal gene (H) codes for normal clotting.
Sex-Linked Traits
XhXh –female with hemophilia
XHXh – female carrier
XhY – male with hemophilia
XHY – normal male
XHXH – normal female, not a carrier
Multiple Alleles -traits controlled by more than two alleles in a population.
Each individual has two genes for blood type, but 3 alleles exist in our population.
The type A allele and the type B allele are codominant. Type 0 is recessive. This gives us 4 blood types.