Biology Key Terms and Concepts

Key Biological Terms

• Renal: Relating to the kidneys
• Excretion: Removal of waste from the body
• Filtration: Separating solid matter from a liquid
• Urea: A chemical waste product from protein breakdown
• DNA: Deoxyribonucleic acid; carries genetic information
• Chromosomes: Thread-like structures of DNA containing genes
• Gametes: Reproductive cells (sperm and egg)
• XX: Female sex chromosomes
• XY: Male sex chromosomes
• MRS GREN: Mnemonic for the life processes: Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition
• Kidney Parts: Renal artery, renal vein, ureter, cortex, and medulla
• Kidney Function: Filtering waste and excess water from the blood
• Urine Composition: Water, urea, and salts
• Kidney Failure Causes: High blood pressure and diabetes
• Kidney Failure Treatments: Dialysis and transplant
• Female Reproductive Organs: Fallopian tubes, uterus, vagina, cervix, ovaries
• Uterus: Womb, where the fetus develops
• Fallopian Tube: Connects ovary to uterus; site of fertilization
• Cervix: Entrance to the uterus
• Ovaries: Produce egg cells and hormones
• Male Reproductive Organs: Prostate, urethra, sperm duct, testes, penis, foreskin
• Egg Cell Parts: Jelly coat, yolk, cortical granules, nucleus
• Sperm Cell Parts: Tail, mid-piece, nucleus, acrosome
• Yolk (egg cell): Provides energy for early development
• Nucleus (egg cell): Contains half the genetic material
• Jelly Coat (egg cell): Protects egg and feeds sperm
• Cortical Granules (egg cell): Hardens the egg after fertilization
• Tail (sperm cell): Enables movement
• Mid-piece (sperm cell): Contains mitochondria for energy
• Nucleus (sperm cell): Contains the genetic material
• Acrosome (sperm cell): Aids in fertilization
• Pregnancy Affecting Factors: Alcohol, smoking, and drugs
• Pregnancy Problems: Miscarriage, premature birth, low birth weight, birth defects
• Miscarriage: Embryo/fetus death in early pregnancy
• Premature baby: Born before 37 weeks
• Low birth weight: Less than 5lb 8oz at birth
• Birth defect: Health or life-threatening problem at birth
• Phenotype: Observable physical characteristics
• Genotype: Genetic makeup
• Chromosome 23 Significance: Determines the sex of the offspring
• Heterozygous: Two different alleles for a trait
• Homozygous: Two identical alleles for a trait
• Alleles: Different versions of a gene

Chemistry & Atomic Structure

• Isotopes: Atoms of the same element with different numbers of neutrons
• Periodic Table Arrangement (historical): Ordered by atomic weight
• Mendeleev: Organized the periodic table, leaving spaces for undiscovered elements
• Periodic Table Groups: Indicate the number of electrons in the outermost shell
• Periodic Table Periods: Indicate the number of electron shells
• Density: Mass per unit volume
• Volume Increase and Density: Increased volume results in decreased density
• Shape Effect on Density: Shape affects density only if the volume changes
• Density and Sinking: Increased density leads to sinking
• Group 1 (Periodic Table): Alkali metals
• Group 1 Reactivity Trend: Reactivity increases down the group
• Group 1 Valence Electrons: One valence electron in each element
• Group 1 General Properties: Soft, low density, reactive, conduct electricity
• Group 1 Melting/Boiling Point Trend: Decreases down the group
• Group 1 Density Trend: Increases down the group
• Group 1 Reaction with Water: Forms alkali and hydrogen
• Group 7 (Periodic Table): Halogens
• Group 7 Properties: Diatomic, nonmetals, 7 valence electrons, share electrons
• Group 7 Reactivity Trend: Reactivity decreases down the group
• Group 7 Density Trend: Increases down the group
• Group 7 Melting/Boiling Point Trend: Increases down the group
• Shielding Effect: Inner electrons shield outer electrons from nuclear pull
• Noble Gases Properties: Unreactive, colorless, odorless, monatomic
• Giant Structures: Covalent bonding; strong electrostatic attraction
• Graphite Softeness: Layers that can slide over each other
• Diploids: Cells with two sets of chromosomes
• Haploids: Cells with one set of chromosomes
• Dominant Alleles: Always expressed when present
• Recessive Alleles: Only expressed when two copies are present

Additional Concepts

• Noble Gases (existence): Monatomic
• Halogens (existence): Diatomic
• Diamond Uses: Jewelry, industrial tools
• Silicon Dioxide Uses: Insulators, concrete, glass
• Silicon Dioxide Structures: Different arrangements lead to weak structures
• Simple Covalent Molecules Properties: Low melting/boiling points, non-conductive, often gaseous/liquid
• Relative Mass Formula: Sum of the masses of all atoms