SCIENCE EXAM

• Embryology


  The scientific study of embryos and their development
• Homologous Structure


  • Physical structures of organisms that have the same evolutionary origin and positions
  • Have the same structure but different function
• Evolutionary Origin


  The process of gradual change in the development of species
• Vestigial Structure


  • Structure of animals which is gradually disappearing
  • Was useful before but is now useless
• Evidences of Evolution

  • Embryology
  • Homologous Structure
  • Vestigial Structure
  • Genetics
  • Fossils
• Genetics


  • Has shown that all life consists of similarities in nucleotide sequence and proteins
  • Single-Gene
  • Chromosomal
  • Multifactorial
• Fossils


  • The preserved remains of plants and animals
  • Oldest discovered were 3 billion years old in Western Australia
  • Radioisotope dating with the help of paleontologists
  • We cannot study evolution without fossils
• Theory of Evolution by Natural Selection (Survival of the Fittest)


  • Living things produce more offspring than can actually survive
  • Each organism has the ability to survive
  • Variation from species
  • Variation of members of a species
  • Living things that survive and reproduce pass their genetic traits to their offspring
• Evolution


  Changes through mutations occur in the genetic sequences of living things
• Adaptation


  A biological mechanism by which organisms have the ability to adapt themselves to fast-changing environments
• Variation


  Heritable differences among single species resulting from differences in the genetic traits of the living organism inherited from a parent or due to genetic mutations
• The Theory of Evolution by Natural Selection was already accepted by many biologists because of many valid explanations and evidences seen on Earth
• Charles Robert Darwin is the most popular evolution scientist who proposed this theory
• Gene Flow


  • The transfer of alleles from one population to another population
  • Their alleles become part of their new population's gene pool
  • When gene flow does not occur, there is no chance that two populations will evolve into different species
• Genetic Drift


  • A change in allele frequencies that affect an organism to be eliminated
  • A small population of organisms is more likely to be affected by chance
  • Alleles decrease and eliminate because of limited chance
  • Causes a loss of genetic diversity in a population
• Mutation


  • Will create another genetic variation needed for evolution
  • One of the bases of natural selection since mutations in germs may be passed to offspring
  • Occurs in the DNA sequence, which causes a nucleotide base to be inserted, deleted, or substituted
• Sexual Selection


  • When animals choose their mate partners based on special traits they find attractive
  • Mating is an important effect on the evolution of a population
  • Female animals have a greater chance to select their mates
• Types of Sexual Selection

  • Intersexual Selection
  • Intrasexual Selection
• Intersexual Selection


  Happens when a male displays unique traits that attract the female
• Intrasexual Selection


  • Happens when there is competition among males
  • The one who wins will be the female's mate
• Allopatric Speciation


  Occurs when there is an imbalance of gene flow between two populations due to a physical barrier
• Sympatric Speciation


  Occurs if there is an overlapping range of the two diverging species within a region or locality
• Parapatric Speciation


  Occurs when there is limited gene flow that may diverge from a single species following the hybridization of a population
• Speciation


  When new species arise and/or form
• Extinction


  When existing species lose and cease to exist, completely disappearing from the Earth
• Extinction leads to


  Loss of genetic diversity
• Extinction


  Disrupts ecosystems and can cause other species to adapt and fill empty roles
• Environmental changes


  Can cause extinctions and put pressure on surviving species to adapt and evolve
• Species Diversity


  • The variety of species or organisms represented in a particular community
  • The number of distinct species in a specific area
• Energy


  The ability to work and move physically or mentally
• Entropy


  • The opposite of energy
  • The depletion of energy or the inability to use energy due to its dissipating in the environment
• Energy Pyramid

  • Primary Producers (sun's energy)
  • Primary Consumers
  • Secondary Consumers
  • Third Level Consumers
  • Apex Predators (Quaternary Consumers)
• Primary Producers


  • Producers who can naturally manufacture their own energy (PHOTOSYNTHESIS)
  • Includes PLANTS and PHYTOPLANKTONS
  • They are the ones who will start the cycle
• Primary Consumers


  • Consumers who eat plants (HERBIVORES)
  • They consume DIRECTLY (they consume plants directly) and INDIRECTLY (have healthy relationship with plants like bees)
• Secondary Consumers


  • Consumers who eat meats (CARNIVORES)
  • Animals who eat other animals to get energy and food
• Third Level Consumers


  • Consumers who eat both plants and animals (OMNIVORES)
  • Animals that are able to eat plants and other animals to get energy
• Apex Predators (Quaternary Consumers)


  • Top predators of the food chain
  • Mostly carnivores or omnivores
  • Any animals that don't have a natural predator
• Decomposers


  Break down tissues of dead plants or animals and absorb the remaining nutrients which then converts into soil
• Abiotic Environmental Factors That Influence the Survival of Organisms

  • Water
  • Temperature
  • Light
  • Atmospheric Pressure (Gravitational Pressure of the Earth)
  • Chemical Components
• Adaptation


  • The result of evolution in which species undergo changes over a long period of time
  • Happens when a gene mutates or changes by accident
  • A way for a species to survive in an environment by physically and genetically adapting to its surroundings