Themes of biology

• 5 major themes of Biology

  • Organization
  • Information
  • Energy and matter
  • Interactions
  • Evolution
• Theme 1: New Properties Emerge at Successive Levels of Biological Organization

  • The hierarchy of life on earth: biosphere, ecosystem, community, population, organism, organ system, organ, tissue, cell, organelle, molecule and atom
  • With each set up, new properties emerge (emergent properties) because of interactions among components at the lower levels
• Structure and function of biological components

  • They are interrelated
  • At each level of the biological hierarchy, a correlation of structure and function can be observed
• Hummingbird's anatomy


  • Wings can rotate at the shoulder
  • Allows hummingbirds to fly backward or hover in place
  • Can extend long, slender beaks into flowers and feed on nectar
• Cell


  • Basic unit structure with function of an organism
  • Lowest level of organization that can perform all activities required for life
  • Cells are either prokaryote or eukaryote
• Eukaryotic cell


  • Contains membrane-enclosed organelles, including DNA in nucleus
• Prokaryotic cell


  • Lacks membrane-enclosed organelles
• Theme 3: Life requires the conversion of energy
• Gene expression


  DNA sequences (called genes) act as instructions to make a cell's protein production by being transcribed into mRNA and then translated into specific proteins
• Gene expression can also produce some RNAs that are not translated into proteins but serve other important functions
• Chemicals in the environment are taken up by plants


  Plants take up chemical from the soil and air
• Chemicals from plants are consumed as food


  Chemical energy is passed to consumers
• Decomposers break down leaf litter and dead organisms


  Chemicals are returned to the soil
• Feedback regulation


  A process is regulated by its output or product. In negative feedback, regulation of the product slows its production. In positive feedback, a product speeds up its production.
• Feedback is a type of regulation common to life at all levels, from molecules to ecosystems
• Evolution


  The process of change that has transformed life on Earth, accounts for the unity and diversity of life. It also explains evolutionary adaptation and the match of organisms to their environments.
• Bacteria and Archaea consist of prokaryotes. Domain Eukarya includes various groups of eukaryotes as well as fungi, plants, and animals.
• Natural selection is the evolutionary process that occurs when a population is exposed to environmental factors that consistently cause individuals with certain heritable traits to have greater reproductive success than do individuals with other heritable traits.
• Scientific research and the development of new tools and techniques have undoubtedly improved the quality of our lives.
• Biology is the study of living things that help us to understand every organism.
• Advances in medicine, agriculture, biotechnology, and many other areas of biology have brought improvements in the quality of life.
• Fields such as genetics and evolution give insight into the past and can help shape the future, and research in ecology and conservation inform how we can protect this planet's precious biodiversity.
• The food that we consume is the results of agriculture. Humans and animals depend on the agricultural products for sustaining themselves.
• Agriculture


  Defined to produce commodities which maintain life, including foods, fibers, forest products, agricultural crops, horticultural crops, and their related services.
• Myanmar's agricultural exports


  • rice, blackgram, greengram, pigeonpea, chickpea, sesame, onion, tamarind, raw rubber
• Myanmar's farms are well diversified, with most farms producing rice paddy during the monsoon season and other crops such as beans, pulses, oilseeds and maize, during the cool and dry seasons.
• Rice (Oryza sativa) production is based on its environment, resulting in rain fed lowland rice, winter rice, deep-water rice, upland rice and irrigated rice.
• The traditional method for cultivating rice is flooding the fields while, or after, setting the young seedlings. This simple method requires sound irrigation planning but reduces the growth of less desirable plants.
• Protein oposon


  Membrane-enclosed organelles
• DNA


  Throughout nucleus
• Size of eukaryotic and prokaryotic cells contrasted in Figure 1.2 is 1 μm
• Figure 1.2 contrasts eukaryotic and prokaryotic cells in size and complexity
• Theme 2: Life's Processes


  Involve the Expression and Transmission of Genetic Information
• Genetic information


  Encoded in the nucleotide sequences of DNA
• DNA


  Transmits heritable information from parents to offspring
• Gene expression


  DNA sequences (called genes) act as instructions to make a cell's protein production by being transcribed into mRNA and then translated into specific proteins
• Gene expression can also produce some RNAs that are not translated into proteins but serve other important functions
• Inherited DNA directs development of an organism

  1. DNA from both parents in fertilized egg

  2. Copies of inherited DNA in embryo's cells

  3. Offspring inherits traits from both parents