|Cells||Cellular Growth and Development|
All living organisms are made up of cells.
Cells vary in structures and function.
A cell’s genetic information, housed in the DNA, determines the specific function of the cell.
Cell Membrane: flexible outer boundary of a cell made of a double layer of non-polar fatty acids, proteins, and other elements that float freely around; selectively permeable so it regulates what leaves/enters a cell
Cell Wall: rigid, outermost boundary that holds the cell’s shape; only found in plant cells
Central Vacuole: large membrane bound space used for storage; only in plant cells
Chloroplasts: organelles that converts light energy into carbohydrates to use as a food source; only in plant cells
Cilia: short hair-like fibers outside of the cell membrane used to move a cell or move objects along the cell’s membrane
Cytoplasm: the fluid within the cell membrane that houses all other organelles
Endoplasmic Reticulum (ER): system of internal membranes that moves proteins within a cell and produces membrane for other
Flagella: long threadlike fibers used to propel a cell for movement
Golgi Apparatus: “protein warehouse” that modifies and packages newly made proteins
Lysosomes: small organelles that breaks down material using digestive enzymes
Microfilaments: protein fibers used to hold the cell’s shape
Microtubules: hollow tubes made of protein that serve as “tracks” along which information from DNA can pass
Mitochondria: organelle which uses chemical potential energy from the breakdown of food to produce energy (in the form of ATP) that allows the cell to do work
Nucleus: membrane-bound organelle that contains the cell’s DNA
Organelle: unit within a cell that carries out a specific function
Ribosome: organelle that makes proteins using the instructions given by DNA; can be free-floating inside cell or bound to rough endoplasmic reticulum
Rough Endoplasmic Reticulum (RER): part of the endoplasmic reticulum with ribosomes attached to it; responsible for building proteins
Smooth Endoplasmic Reticulum (SER): part of the endoplasmic reticulum with no ribosomes; builds lipids and breaks down toxic substances
Vesicle: small, membrane bound sac used for transport
All cells are separated into two categories: Prokaryotic cells and Eukaryotic cells
Prokaryotes: single-cell organisms that do not have a nucleus or membrane bound organelles; includes most bacteria
Eukaryotes: : both single and multi cell organisms that have a nucleus and membrane bound organelles; includes all plant, animal, protest and fungi cells
Gene: part of a strand of DNA that codes for a specific characteristic; passed down from parents to offspring
Mutations: changes in a gene’s chemical structure; changes the information that the gene codes for; changes can help or hurt the organism.
– If mutations occur within a gamete, or sex cell, then the mutation will be passed from parent to offspring.
– If mutation occur within a somatic cell, or non-reproductive cell, the mutation will only be in the cells derived from the mutated cell.
Cancer: uncontrolled division of mutated cells
-Gregor Mendel (1822-1884) was an Augustinian monk was the first to document findings on inherited traits using pea plants
– Each organism has two copies of each gene; one from each parent
– Different genes can code for the same trait, but have different versions of the trait. Two genes could code for eye color, but one codes for blue, while the other codes for brown. These different versions are called alleles
Dominant trait: the version of the trait that is expressed; the dominate allele
Recessive trait: the version of the trait that is present but not expressed; the recessive allele
Homozygous: when both alleles of a trait in an individual are the same
Heterozygous: when both alleles of a trait in an individual are different; the dominate allele is expressed
Mendel’s Law of Segregation: Alleles separate when gametes are formed.
Mendel’s Law of Independent Assortment: The separation of alleles during the formation of gametes occurs independently for individual traits
Genes from parents can be arranged in a variety of ways.
Punnett squares can be used to predict the different combination of alleles for one trait, and the probability for each of these combinations.
In the example to the right, R is the dominant allele for red flowers, and r is the recessive allele for white flowers. There is a 50% chance for the offspring to be red, and 50% chance for the offspring to be white
Virtually all life forms are created through the assembling of proteins that follow instructions written by DNA.
All humans have 23 pairs of chromosomes. These chromosomes have genes that encode for the same traits. However, it is the different combination of alleles that make individual humans unique.
Each species has its known number of chromosomes and a unique pattern for the traits that the genes encode for.
Other forms of variation can be caused by changes in genes other than mutations, such as deleting genes, duplicating genes, crossing over, and jumping genes.
Crossing over: the exchange of genetic material between homologous, or a pair of identical, chromosomes
Jumping genes: when genes bind to or “jump” to another chromosome
Ecological Levels: Biosphere → Biomes → Ecosystems → Communities → Populations → Organisms
Biotic Factors: the living things that exist in and influence an environment
Abiotic Factors: the non-living things that exist in an influence an environment
Limiting Factors: any factor that restricts an organism’s ability to successfully thrive in an environment.
Energy Cycle: Sunlignt → Autotrophs → Heterotrophs → Decomposers
Autotrophs: organisms that use energy from the sun or chemicals to produce food
Heterotrophs: organisms that rely on the consumption of organisms for energy
Types of Heterotrophs
-Herbivores: organisms that consume only plants
-Carnivores: organisms that consume only other animals
-Omnivores: organisms that consume both plants and animals
-Detrivores: organisms that consume matter as it decomposes
-Decomposers: organisms that consume dead plant or animals and convert it into inorganic matter
Food Webs: a diagram showing the connections between energy cycle (trophic) levels for all organisms in an environment
|Types of Organisms|