Biology Lecture Notes Review

Flashcards on the characteristics of life, cell structures, biological organization, cell cycle, DNA replication, and genetics.

Characteristics of Life

Made of cells, heredity, maintain homeostasis, respond to stimuli, maintain metabolism, grow and develop, reproduce.

Prokaryotes

Lack organelles, contain ribosomes, lack a nucleus, single-celled.

Eukaryotes

Contain organelles, contain ribosomes, contain a nucleus, single and/or multi-celled.

Nucleus

Contains DNA, control cell's activities.

Nucleolus

Site of ribosome synthesis, found in nucleus.

Mitochondria

Breaks down carbohydrates to produce ATP (usable energy).

Rough Endoplasmic Reticulum

Transports proteins and other substances within cell.

Smooth Endoplasmic Reticulum

Creates lipids.

Ribosomes

Protein synthesis.

Chloroplast

Synthesis carbohydrates using light energy.

Golgi Apparatus

Protein packaging.

Cytoplasm

Supports and protects organelles.

Centrioles

Paired cylindrical organelles utilized in cell division.

Cytoskeleton/Microtubules

Supports cell, provides shape, and used in cell movement.

Lysosome

Breaks down food molecules, and old organelles.

Vacuoles

Storage, digestion and waste removal.

Contractile Vacuole

Pumps water out of cell.

Vesicle

Moves proteins, lipids, and carbohydrates through cell.

Cell Membrane

Protects contents of the cell, controls what enters and leaves cell.

Cell Wall

Protects contents of cell and prevents cells from bursting.

Levels of Biological Organization

Organelles → cells → tissues → organs → organ systems → multi-cellular organisms

G1 Phase

Cell grows.

S Phase

DNA is copied.

G2 Phase

Cell continues to grow, organelles are copied.

Prophase (Mitosis)

Spindle fibers form, nuclear envelope dissolves, chromosomes become visible.

Metaphase (Mitosis)

Chromosomes align at the cell's equator, spindle fibers attach to chromosomes.

Anaphase (Mitosis)

Spindle fibers pull chromatids apart at centromere, chromatids move to opposite poles.

Prophase I (Meiosis)

Chromosomes become visible, Nuclear envelope disappears, Crossover occurs

Metaphase I (Meiosis)

Homologous chromosomes move to equator

Anaphase I (Meiosis)

Homologous chromosomes move to opposite poles

Telophase I (Meiosis)

Cytoplasm divides

Prophase II (Meiosis)

New spindle fibers form around the chromosomes

Metaphase II (Meiosis)

Chromosomes align up at the equator

Anaphase II (Meiosis)

Centromeres divide, Chromatids move to opposite poles

Telophase II (Meiosis)

Nuclear envelope reforms around each set of chromosomes, Cytoplasm divides

Cytokinesis

Splitting of the cell membrane into two separate cells.

Mitosis

One division into two identical diploid cells.

Meiosis

Two divisions resulting in 4 haploid cells.

DNA replication

Process of making an exact copy of DNA; occurs in the S phase of the cell cycle.

Chromosomes

Long strands of DNA.

DNA

Genetic material that codes for the hereditary traits of organisms.

Genes

Segments of DNA that is located in a chromosome and that code for a specific hereditary trait.

Alleles

Alternative forms of a gene that governs a characteristic, such as hair color.

Adhesion

Attraction of water for a wettable surface.

Cohesion

Attraction of one water molecule for another water molecule.

Organic Compounds

Presence of both carbon and hydrogen.

Carbon Properties

Carbon atoms can share electrons with a wide veriety of elements.

Carbohydrates Building Blocks

Monosaccharides (Monomer) → Disaccharides → Polysaccharides (Polymer/Macromolecule)

Proteins Building Blocks

Amino Acid (Monomer) → Polypeptide Chains → Protein (Polymer/Macromolecule)

Nucleic Acid Building Blocks

Nucleotide (Monomer) → DNA/RNA (Polymer/Macromolecule)

Cellulose

Complex carbohydrate that provides structural support for plants.

Phospholipids

Make up the lipid bilayer of cell membranes.

Sterols

Perform as hormones or signaling molecules; include cholesterol, estrogen and testosterone.

Glycerol

Stores large amounts of energy.

Hormones

Messenger proteins which help to coordinate certain bodily activities.

Antibodies

Travel through the blood stream and are utilized by the immune system to identify and defend against bacteria, viruses, and other foreign intruders.

Enzymes

Referred to as catalysts because they speed up chemical reactions.

Structural Proteins

Provide support. Examples include keratin and collagen.

Transport Proteins

Move molecules from one place to another around the body.

DNA

Stores hereditary information; consists of two strands of nucleotides twisted around each other.

RNA

Used in the manufacturing of proteins; single strand of nucleotides that code for a specific protein to be made by the cell.

Substrate

Molecule that an enzyme acts on.

Genotype

Pair of alleles that an organism receives from its parents.

Homozygous genotype

Genotype that the alleles are the same.

Heterozygous genotype

Genotype that the alleles are different.

Phenotype

Physical expression of the pair of alleles for a specific trait.

Polygenic Traits

Traits that are determined by the combined effect of more than one pair of genes.

Incomplete Dominance

Results in an intermediate expression of a trait in heterozygous individuals.

Multiple Alleles

Genes with three or more alleles.

Codominance

Two dominant alleles are expressed at the same time.

Sex-linked Traits

Gene that is found only on the X chromosome and not the Y chromosome.

Crossing Over

Exchange of genetic material between homologous chromosomes that results in recombinant chromosomes; occurs during Prophase I of meiosis.

Nondisjunction

Failure of chromosome pairs to separate properly during meiosis stage 1 and stage 2, specifically in anaphase.

Deletion

Removal of one or more nucleotides from the DNA.

Inversion

Segment of a chromosome is reversed end to end.

Translocation

Chromosome abnormality by rearrangement of parts between nonhomologous chromosomes.

Silent Mutations

DNA mutations that do not result in a change to the amino acid sequence of a protein.

Nonsense Mutations

Point mutation in a sequence of DNA that results in a premature stop codon.

Missense Mutations

Point mutation in which a single nucleotide is changed, resulting in a codon that codes for a different amino acid.

Transcription and Translation

Overall process is similar, the lack of a nucleus makes the process somewhat different in prokaryotes and eukaryotes.

mRNA

RNA that is transcribed from DNA for the purpose of protein synthesis.

Ribosomes

Large complex composed of many molecules, including ribosomal RNAs and proteins; translates the mRNA genetic code to a specific sequence of amino acids that make up a protein.

protein Synthesis Organelles

Endoplasmic reticulum, tRNAs, Golgi apparatus, and Nucleus

Selective Breeding

Process of breeding plants and animals for particular traits.

Gene Splicing

Cutting the DNA from one organism and attaching it to the DNA of another organism causing the host organism to demonstrate a new phenotype.

Cloning

Process of producing similar populations of genetically identical individuals that occurs in nature when organisms reproduce asexually.

Gene Therapy

DNA can be used to supplement or alter genes within an individual's cells as a therapy to treat disease.

Stem Cell Therapy

Intervention strategy that introduces new adult stem cells into damaged tissue in order to treat disease or injury

Photosynthesis - Plastids

Conversion of light into glucose.

Cellular Respiration - Mitochondria

Converts glucose into ATP

Photosynthesis Chemical Equation

6H20 + 6 CO2 + solar energy →> C6H1206 + 60г

Cellular Respiration Chemical Equation

C6H1206 + 6 02 > 6 CO2 + 6H20 + energy (heat, light, ATP, etc.)

ATP

Nucleotide used for energy storage.

Natural Selection

Increase the frequencies of alleles if they are advantageous to a species' survival and reproductive abilities.

Geographic Isolation

Species occur in different areas, and are often separated by terrestrial and aquatic barriers.

Temporal Isolation

Individuals do not mate because they are reproductively active at different times.

Ecological Isolation

Individuals only mate in their preferred habitat.

Behavioral Isolation

Individuals of different species may meet, but one does not recognize any sexual cues that may be given.

Mechanical Isolation

Copulation may be attempted but transfer of sperm does not take place.

Gametic Incompatibility

Sperm transfer takes place, but the egg is not fertilized.