Chapter 1: Characteristic of living organisms

• Cell surface receptors allow cells to detect chemical signals in their environment.
• Plants in the plant kingdom are commonly green due to chlorophyll, which is used to absorb energy from sunlight
• Plant features:

  • Cell wall made of cellulose
  • Feed by photosynthesis
  • Generally have roots, stems, and leaves
  • Chloroplasts contain chlorophyll
  • Large vacuole
  • Feed saprophytically by secreting enzymes onto food outside the body to break it down for nutrient absorption
• Fungi in the fungus kingdom:

  • Made of microscopic threads called hyphae
  • When many hyphae come together, they form mycelium
  • No chlorophyll
  • Can be multicellular or unicellular
  • Example: mushrooms
  • Reproduce by forming spores
• Animals in the animal kingdom:

  • Eukaryotes
  • Cells with DNA found in a nucleus known as eukaryotic cells
• Prokaryotes in the animal kingdom:

  • Cells without a nucleus, with DNA floating around the cytoplasm
  • Vesicles store solutions called cell sap
  • Mitochondria are where aerobic reactions take place
• Characteristics of living organisms:

  • Movement
  • Respiration
  • Sensitivity
  • Growth
  • Reproduction
  • Excretion
  • Nutrition
• Classification: Putting things in groups
• Biology classification system:

  • Binomial name: two-part name (genus species)
  • Rules: first word capitalized, second word in lowercase, underlined if unable to reproduce
• common ancestors: species that lived in the past that given offspring of several type of species.
• Species: A group of organisms that can breed to produce fertile offspring.
• Arthropods:

  • Insects (e.g., dragonfly) have three pairs of jointed legs, two pairs of wings, and breathe through tubes called tracheae
• Arachnids (e.g., spiders) have a body divided into head, thorax, and abdomen, four pairs of jointed legs, and one pair of antennae
• Myriapods (e.g., centipedes) consist of numerous similar segments, each with jointed legs and one pair of antennae
• Crustaceans (e.g., lobster) have more than four pairs of jointed legs, two pairs of antennae, and a body divided into cephalothorax and abdomen
• Plant kingdoms:

  • Ferns reproduce by spores produced on the underside of their fronds and do not produce flowers
• Monocots have seeds with one cotyledon, roots growing directly from the stem, leaves with parallel veins, and three petals
• Dicots have two seeds with cotyledons, a main root and side roots, a network of veins, and four or five petals
• Flowering plants reproduce using flowers and seeds, with seeds produced inside the ovary in the flower
• Groups within the Animal kingdom:

  • Fish are vertebrates with scaly skin, have gills throughout their lives, and fins
• Reptiles (e.g., snakes) are vertebrates with scaly skin and lay eggs with soft shells
• Amphibians (e.g., toads) are vertebrates with skin, no scales, and lay eggs without shells
• Birds have feathers, a beak, wings as their front limbs, and lay eggs with hard shells
• Mammals have hair on their skin, young that develop in the mother's uterus, mammary glands producing milk, different types of teeth, a pinna (ear flap), sweat glands, and a diaphragm
• Vertebrates are animals with backbones
• Protoctist kingdom:

  • Contains cells that are animal-like or plant-like, mostly unicellular but some multicellular
• Animal-like cells in Protoctists:

  • Usually unicellular, lack a nucleus (prokaryotic), have cell walls not made of cellulose, no mitochondria, and often have plasmids
• Plant-like cells in Protoctists:

  • Multicellular or unicellular, have a nucleus, may or may not feed by photosynthesis, and may feed on organic substances made by other organisms
• Growth is a permanent increase in size and dry mass
• Sensitivity


  Ability to detect and respond to changes in the internal and external environment
• Nutrition


  Taking in of materials for energy, growth and development
• Action by an organism causing a change in position or place
• Characteristics of living organisms

  • Movement
  • Respiration
  • Sensitivity
  • Growth
  • Reproduction
  • Excretion
  • Nutrition
• Genus is a group of similar species
• Classification

  Putting things in groups
• Excretion


  Removal of waste products of metabolism and excess of requirements
• Species is a group of similar individuals
• Respiration


  The chemical reactions in cells that breaks down nutrient molecules and release energy for metabolism
• Binomial name is a two-part specific name
• Reproduction


  Processes that make more of the same kind of organism