Bio 114
A general, unifying explanation of observations is a Hypothesis
When biologists wish to study the VERY small internal organelles in cells, they most likely would use a transmission electron microscope.
When biologists wish to see just the cell membrane & possibly the nucleus in a cell, they most likely would use a light microscope.
When calculating the total magnification of an image, multiply the objective power times the ocular power. Their ocular power is always 10.
The Coarse Adjustment is NEVER use while viewing a specimen under high power
The advantage of light microscopy over electron microscopy is that light microscopy allows one to view processes in living cells.
Magnification & resolution are inversely related (as the magnification increases, the resolution decreases).
All living things are composed of 1 or more Cells.
Homeostasis is the Process by which an individual keeps internal conditions within tolerable ranges.
Both Asexual & Sexual Reproduction transmit genetic information from 1 generation to the next.
The Characteristics of Life include: Organization, Energy & Metabolism to Maintain Homeostasis, Growth & Development, Adaptation, Response to stimuli, Movement, Reproduction
The sugar in a glass of Kool Aid is the Solute. The water is the Solvent. The Kool Aid is the Solution.
Prokaryotic cells have No Nucleus but have Nucleoid Regions. They have no organelles but have Ribosomes. They have a Cell Membrane & can have Cell Walls. Examples are Bacteria Cells.
Eukaryotic cells have a Nucleus. They have organelles. They have a Cell Membrane & can have Cell Walls. Examples are Animal cells (including human), Plant Cells, Fungi Cells, Protist Cells
A key problem faced by a very large cell is that it has too much volume for its surface area. As a result, it would run short on food and wastes would build up inside the volume of the cell.
The plasma membrane of a cell is fluid & semi-permeable
Enzymes speed up chemical reactions by lowering Activation energy. They are specific to their substrate & are not consumed (used up)
Anatomy of a Phospholipid is that the tails are Hydrophobic so they have to be protected from the water outside the cell & inside the cell
Diffusion is a passive process in which molecules move from a region of higher concentration to a region of lower concentration. It doesn’t require an expenditure of energy by the cell because it’s moving down the concentration gradient. It occurs until Equilibrium is reached but then the particles can keep moving. There is just not NET change in movement.
Osmosis is a type of Passive Transport that moves water from an area of high concentration to an area of low concentration without using cellular energy.
Hypotonic means there is more solute inside the cell than outside. They have more water molecules tied up with solute inside the cell than out. There are more free water molecules outside the cell than inside. The water wants to move into the cell
Hypertonic means there is more solute outside the cell than inside. They have water molecules tied up with solute outside the cell than out. There are more free water molecules inside the cell than outside. The water wants to move out of the cell
Isotonic means there are equal amounts of solute both inside & outside.
Endocytosis is a type of Active Transport that takes material into cells. Examples are Pinocytosis which is taking in liquids & Phagocytosis which is taking in solids
Organisms that make their own food are called Autotrophs.
When we look at a plant, we see green because the green light is reflected by the chlorophyll
Animal cells go through Cellular Respiration. Plant cells go through Photosynthesis & Cellular Respiration.
Aerobic Reactions require Oxygen. Anaerobic Reactions do not.
Glycolysis is anaerobic and occurs in the cytoplasm
The Kreb’s cycle is aerobic and occurs in the mitochondria
The electron transport chain is aerobic and occurs in the mitochondria
The Electron Transport Chain in Cellular Respiration makes the most ATP
Photosynthesis releases oxygen, uses energy to drive the dark reactions, creates glucose, and takes place in the chloroplast
cellular respiration consumes oxygen, generates energy in the form of ATP, uses glucose, and takes place in the mitochondria
In each of your body cells you have two copies of each Chromosome. One of them you inherited from your father, the other from your mother. These matching (but not exactly identical) chromosomes are called Homologous Chromosomes
In humans, sex determination is controlled by the SRY gene on the Y-Chromosome.
When the cell is NOT preparing to divide, the genetic material is found in the form of Chromatin
46 is the number of Chromosomes in Diploid, 2N, Zygote Cell
To determine the number of Chromosomes in a Haploid, N, Gamete, Egg, or Sperm Cell, divide the number in the chart in ½
In humans, there are 46 total Chromosomes & 23 pairs
In humans, there are 44 Autosomes & 22 pairs
In humans, there are 2 Sex Chromosomes & 1 pair
XX is female & XY is male
The Dad’s sperm determines the sex of the baby
Mitosis conserves the chromosome number, makes Diploid Cells, is used for growth & repair, and forms 2 Daughter Cells, the daughter Cells are identical to parent cells, and the daughter Cells are identical to each other.
Meiosis reduces/halves the chromosome number, makes haploid cells, creates gametes, and forms 4 daughter cells, the daughter cells are different from parent cells, and the daughter cells are different from each other.
During Prophase Chromosomes Condense
During Metaphase Chromosomes line up on the Equator of the Cell
During Anaphase Chromosomes split at the Centromere and separate the Sister Chromatids.
During Telophase there are two Nuclei are located in one Cell
The Cell Plate separates plant cells in cytokinesis. In animal cells, this is accomplished by the Cleavage Furrow.
Checkpoint Proteins make sure that cells divide only when and where it is helpful for the whole organism. They also prevent cells with damaged DNA or abnormal chromosome numbers from making daughter cells.
Metastasis occurs when cells break away from an initial tumor, enter blood or lymph vessels, and establish new tumors elsewhere
Prophase I of Meiosis I is where crossing over can occur.
Meiosis II is a lot like Mitosis; it separates sister chromatids to produce cells where each chromosome is represented by only one strand of DNA.
After Interphase, Cells have duplicated copies of Chromosomes. This means each Chromosome looks like an “X” instead of a line.
A segment of DNA that transmits information from parent to offspring is called a Gene.
In DNA A pairs with T & C pairs with G
When one DNA molecule is copied to make two DNA molecules, the new DNA contains 50% of the parent DNA. This is because each new strand contains 1 copy of old DNA & 1 copy of new DNA.
Any permanent change in the nucleotide sequence of DNA is called a mutation.
The structure of all DNA (it can be plant, animal, protist, fungi etc….) is the same except for the order of the Nitrogen Bases.
DNA Nucleotides are made of a 5-Carbon Sugar called Deoxyribose, a Phosphate Group & a Nitrogen Base
All cells in your body have exactly the same DNA. The cells are different; your muscle cells express only their genes to make muscle-specific proteins; a different set of genes is “turned on” in brain cells.
The flow of genetic information being expressed is DNA → RNA → protein
RNA has Uracil instead of Thymine
In Eukaryotic organisms, Transcription happens in the Nucleus and Translation happens in the Ribosomes of the Rough ER that is in the Cytoplasm
The tRNA has Anticodons that match up to the Codons on the mRNA & transfer the appropriate Amino Acid to make a Protein
When using this chart be sure to look up the mRNA to find the Amino Acids. A chain of Amino Acids is a Protein
A Cloned animal has the same genetic information as the Somatic Cell Donor
A Mutation is a naturally occurring process that can happen anytime DNA is copied or damaged, but it happens more often if the DNA is exposed to synthetic chemicals or radiation. It can have a range of effects on organisms.
A plant with purple flowers is allowed to self-pollinate. Generation after generation, it produces purple flowers. This is an example of True-Breeding
An individual’s observable traits (physical appearance) are called the Phenotype
A Genotype that has 2 identical Alleles for a given characteristic is known as Homozygous. 2 Different Alleles are Heterozygous
If a trait is Dominant, this means that individuals Homozygous Dominant for the Allele producing this trait have the same Phenotype as Heterozygotes; only Homozygous Recessive individuals look different.
Punnett squares are used for predicting the result of genetic crosses between organisms of known Genotypes
Sex Linked Traits are found on the X Sex Chromosomes. Males are more often affected by sex-linked traits than females because only have 1 of the X chromosome.
Down Syndrome is caused by an error in meiosis which produces an egg or sperm with two copies of a chromosome
Most inherited disorders (those that run in families) are Recessive because Heterozygotes successfully reproduce, passing along the Allele that can cause the disorder in Homozygous Recessives.
In inherited recessive disorder, if the parents are Heterozygous carriers they do not have the disorder but can have a child with the disorder if they both pass on the Recessive Allele.
Plants, Algae & Bacteria are examples of Autotrophs which are also called Producers
Organisms that eat only animals are called Carnivores. Organisms that obtain energy by eating only plants are called Herbivores.
A group of organisms that can breed & produce fertile offspring is part of the same Species.
Disease, Death & Emigration will all decrease population size__.__
An organism’s habitat is destroyed so it moves to a different area and joins that population is an example of immigration
A Limiting Factor is a factor that causes population growth to decrease.
Food, Disease & Predation are all density-dependent factors. Droughts, hurricanes, and Deforestations are all density-independent factors.
When organisms attempt to use an ecological resource in the same place at the same time it is called Competition
An example of Mutualism is when insects help pollinate the flowers and the flowers provide the insects with food.
An example of Parasitism is when tapeworms live in the intestine of humans and steal nutrients is called
An example of Commensalism is when barnacles attach to a whale and benefit from the constant movement of water and the barnacles don’t help or hurt the whale
A Habitat is where an organism carries out its life.
Humans are burning fossil fuels more quickly than the earth can replenish them and this has altered the Carbon Cycle.
Cellular Respiration & Combustion (burning) are 2 processes that release carbon into the atmosphere.
Most (97%) of the water on Earth is stored in the ocean.
The Nitrogen Cycle requires bacteria to convert atmospheric forms into forms that are useful to the environment
Phosphorus does not travel through the atmosphere at some point in the cycle
The 1st species (in secondary succession) is called the Pioneer Species.
The final, most stable species (in secondary succession) is called the Climax Community
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