Biological Science

• Biology is a natural science discipline that studies living things
• It is a very large and broad field due to the wide variety of life found on Earth, so individual biologists normally focus on specific fields
• Epidermis


  The outer layer of the skin that you can see or feel. It protects the body from damage and helps regulate body temperature
• Dermis


  The layer under the epidermis. It contains nerve endings, blood vessels, oil glands, and sweat glands
• Hair


  Grows from follicles found in the dermis. Even before an object touches the skin, the hair makes it possible to feel that object
• Hair bulb


  Forms the base of the hair follicle. In the hair bulb, cells divide to build and grow the hair
• Sweat gland


  Makes sweat. Its main function is to control body temperature. Sweat is mainly water, but it also contains some salts
• Vein


  A blood vessel that returns blood from the skin to the heart. It works together with other blood vessels to keep the blood moving
• Artery


  A blood vessel that carries blood from the heart. The blood carries oxygen and nutrients
• Hypodermis


  The deepest layer of the skin. It connects the dermis layer to the muscles and bones. It contains a layer of adipose tissue
• Adipose tissue


  Also known as body fat. It acts as a layer of insulation and protects the internal organs and muscles
• Capillary


  Tiny blood vessels where exchange of nutrients, oxygen, and waste products occurs
• Cerebellum


  The part of the brain that controls balance, posture, and coordination
• Pancreas


  Regulates blood sugar levels and produces digestive enzymes
• Nephron


  The functional unit of the kidney responsible for filtering blood and forming urine
• Taxonomic ranks from most inclusive to least inclusive

  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species
• Binomial nomenclature


  System of giving every organism two names: genus (more broad) and species (individually specific)
• Natural selection is the process where black ladybugs become more successful in escaping predators, causing the gene for black color to become more popular in the population over time
• Homologous structures are similar structures in different species that have a common evolutionary origin, like the bat forelimb and bird wing
• The screwworm is closely related to the fruit fly based on the comparison of amino acid differences in cytochrome c
• In an ecosystem, species make up populations, which make up communities
• Gibberellic acid stimulates fruit growth and prevents seed formation in seedless grapes
• If a heterozygous black mouse mates with a homozygous brown mouse, 50% of their offspring will have black fur
• Mendel's Particulate Inheritance


  Mendel stated that physical traits are inherited as "particles"
• Trait


  Any characteristic that can be passed from parent to offspring
• Heredity


  Passing of traits from parent to offspring
• Genetics


  Study of heredity
• Types of Genetic Crosses

  • Monohybrid cross
  • Dihybrid cross
• Alleles


  Two forms of a gene (dominant & recessive)
• Dominant


  Stronger of two genes expressed in the hybrid; represented by a capital letter
• Recessive


  Gene that shows up less often in a cross; represented by a lowercase letter
• Genotype


  Gene combination for a trait
• Phenotype


  The physical feature resulting from a genotype
• Law of Independent Assortment

  Alleles for different traits are distributed to sex cells (& offspring) independently of one another
• Dihybrid Cross


  1. Traits: Seed shape & Seed color

  2. Alleles: R round, r wrinkled, Y yellow, y green
• Photosynthesis Reaction


  6 CO2 + 12 H2O + sunlight → C6H12O6 + 6 H2O + 6 O2
• Photosynthesis


  • Converts solar energy into chemical energy used by biological systems
  • Happens in the chloroplasts of plants
• Chloroplasts


  Full of thylakoids stacked in granum, with thylakoid membranes lined by pigments like chlorophyll
• Chlorophyll


  Green pigment that absorbs all wavelength colors except green, which is reflected off
• Photosynthesis Reaction


  1. Light reactions

  2. Dark reactions