Biology STAAR Review

Base-Pairing Rules

DNA: A-T & C-G; RNA: A-U & C-G.

Cytoplasm

Gel-like substance in all living cells.

DNA

Double-stranded molecule containing GCAT nucleotides.

RNA

Single-stranded molecule containing GCAU nucleotides.

S Phase

Phase of cell cycle where DNA replicates.

Transcription

Process of converting DNA to mRNA. Happens in Nucleus.

Translation

Process of synthesizing proteins from mRNA. Happens in Ribosome.

Codon

Three mRNA bases coding for an amino acid.

mRNA

Carries genetic information from DNA to ribosome.

tRNA

Delivers amino acids to ribosome for protein synthesis.

rRNA

Structural component of ribosomes.

Photosynthesis

Converts sunlight into glucose and oxygen. Happens in Chloroplast.

Cellular Respiration

Process converting glucose and oxygen into ATP. Happens in Mitochondria.

Chemical Reactions

Reactants transform into products.

Primary Succession

Ecosystem development starting from bare rock.

Secondary Succession

Ecosystem recovery starting from soil.

Trophic Levels

Producer --> Primary Consumer --> Secondary Consumer --> Tertiary Consumer

10% Rule

Only 10% of energy transfers between trophic levels. 90% lost as heat.

Fitness

Ability to produce more offspring than competitors.

Enzymes

Proteins that speed up chemical reactions by lowering activation energy

Punnett Square

Tool for predicting genetic trait inheritance.

Homozygous Dominant

Genotype with two dominant alleles (BB).

Homozygous Recessive

Genotype with two recessive alleles (bb).

Heterozygous

Genotype with one dominant and one recessive allele (Bb).

Codominance

Both dominant traits expressed simultaneously (spots & stripes).

Incomplete Dominance

Blending of two dominant traits (Red + White = Pink).

Prokaryotic Cells

Cells without a nucleus, primarily bacteria.

Eukaryotic Cells

Cells with a nucleus, all cell types except bacteria.

Somatic Cells

Regular body cells for growth and repair.

Gametes

Sperm & egg cells carrying half the chromosome number

Crossing Over

Gene exchange between chromosome pairs. Increases Genetic Diversity.

Protists

Eukaryotic, often single-celled organisms.

Plant Cells

Contain chloroplasts, cell walls, and vacuoles.

Fungi

Heterotrophic consumers with chitin cell walls.

Biomolecules

Carbohydrates, lipids, proteins, nucleic acids.

Body Organization

Hierarchy: cell → tissue → organ → system --> organism.

Ecosystem Organization

Hierarchy: organism → population → community → ecosystem.

Biotic Factors

Living components of an ecosystem.

Abiotic Factors

Non-living components of an ecosystem.

Taxonomy

Classification of organisms into hierarchical groups.

Scientific Name

Genus name + species name. For organism identification. Avoids confusion with other species.

Evolution

Change in frequency of a population's gene pool.

Natural Selection

Survival of organisms better adapted to environment.

Cladogram

Diagram showing evolutionary relationships.

Symbiosis

Relationships between different species in nature.

Cell Cycle

Includes Interphase (G1, S, G2) Mitosis & Cytokinesis

Mitosis

Cell division process with Prophase, Metaphase, Anaphase & Telophase.

Cytokinesis

Final separation of cells after mitosis.

Viruses

Non-living entities requiring host cells to reproduce.

Lytic Cycle

Fast viral replication causing cell destruction.

Lysogenic Cycle

Slow viral replication integrating into host DNA.

Homologous Structures

Similar structures with different functions indicating common ancestry. (Human arm & Bat wing)

Analogous Structures

Structures in different organisms serving similar functions. (Bee wing & Bat wing)

Vestigial Structures

Structures with no current function, but were important in the past. (Whale leg bone)

Embryology

Study of embryos indicating common ancestry.

Types of Mutations

Substitution, deletion, insertions affecting genetic code.

Transpiration

Water evaporation from stomata in leaves; sucks water up from roots

Plant Reproduction

Involves pistil and stamen for fertilization.

Nitrogen Cycle

Process of nitrogen fixation and denitrification.

Carbon Cycle

Involves photosynthesis and decomposition of organisms.

Concentration Gradient

A force pushing molecules from areas of high concentration to areas of lower concentration

Passive Transport

Movement of molecules across cell membrane from high to low concentration without energy usage (AKA Diffusion)

Osmosis

Water diffusion across a semipermeable membrane.

Hypotonic

Solution causing cell swelling because water enters the cell.

Hypertonic

Solution causing cell shrinkage because water leaves the cell.

Isotonic

Solution maintaining cell size.

Reactants of photosynthesis

carbon dioxide, water, and sunlight

Activation Energy

Energy needed to get a chemical reaction started

Temperature & pH

The two environmental conditions that may cause an enzyme to denature

Genotype

An organism's genetic makeup, or allele combinations.

Phenotype

An organism's physical appearance, or visible traits.

Nucleic Acids

The only biomolecule to contain all 5 CHOPN atoms

Active Site

The location on an enzyme where the substrate binds to

Carbohydrates

Provide quick energy & make up cell walls

Lipids

Provide long-term energy & make up cell membranes

Proteins

Biomolecule that is the main structural component of life

DNA & RNA

Nucleic Acids. Work together to make new proteins.

Gradualism

Slow, gradual change in species over time

Punctuated Equilibrium

Fast, sudden changes in species. Usually due to a disaster.

Mutualism

symbiotic relationship in which both species benefit (happy/happy)

Parasitism

symbiotic relationship in which one species benefits while harming the other (happy/sad)

Commensalism

symbiotic relationship in which one species benefits while the other is unaffected (happy/neutral)

Interphase

G1, S & G2 stages of cell cycle combined.

Cytokinesis

division of the cytoplasm to form two separate daughter cells

Prophase

Stage of Mitosis where nucleus disappears & spindles appear

Metaphase

Stage of Mitosis where chromosomes line up in middle of cell

Anaphase

Stage of Mitosis where chromosomes are pulled away to opposite ends of the cell

Telophase

Stage of Mitosis where two new nuclei form around each set of chromosomes

Capsid

Protein coat surrounding viruses

Host cell

What viruses must have to reproduce

Point Mutation

Substitution mutation, changes only one codon & one amino acid in protein.

Frameshift Mutation

Insertion or deletion mutation, changes many codons & many amino acids in protein.

Endocrine System

Animal system containing glands & hormones

Integumentary System

Animal system containing hair, skin & nails

Lymphatic System

Animal System, essentially the same as the immune system, protects you from pathogens

Xylem

Vascular tissue in plants that carry water up from the roots.

Phloem

Vascular tissue in plants that transports food (glucose) throughout the plant.

Pistil

Female reproductive organ of plants. Consists of Stigma, Style & Ovary.

Stamen

Male reproductive organ of plants. Consists of Anther & Filament.

Stigma

Sticky tip of Pistil to catch pollen.