Science Warm-up 8/11/2014 □Complete the claim and justification activity found inside of your folders. □Attempt this on your own first, and then compare your results with a neighbor in the room. □After you have completed that, please finish the student inventory.

Chapter 1: Introduction A.Wood EHS Campbell 9e

Concept 1.1 □The themes of this book make connections across different areas of biology.

Theme 1 □New properties emerge at each level in the biological hierarchy □Emergent property: □Results from the arrangement and interaction of parts within a system

□Reductionism □Breaking a complex concept into smaller, and more easily understandable, parts. □Ex) Studying the molecular structure of DNA helps us to understand the chemical basis of inheritance □You have to balance emergent and reductionist approaches to a topic

□Systems Biology □Approach that attempts to model the dynamic behavior of the whole biological system based on a study of the interactions among the systems parts. □Ex) How does a change in _______ affect _________?

Theme 2 □Organisms interact with other organisms and the physical environment. □Every organism interacts with its environment, including nonliving factors and other organisms □Both organisms and their environments are affected by the interactions between them

Animals eat leaves and fruit from the tree. Leaves take in carbon dioxide from the air and release oxygen. Sunlight CO 2 O2O2 Cycling of chemical nutrients Leaves fall to the ground and are decomposed by organisms that return minerals to the soil. Water and minerals in the soil are taken up by the tree through its roots. Leaves absorb light energy from the sun. Figure 1.5

Theme 3 □Life requires energy transfer and transformation. □Most common pathway: □Sunlight  Producer  Consumer  Heat

Chemical energy (a) Energy flow from sunlight to producers to consumers Sunlight Producers absorb light energy and transform it into chemical energy. Chemical energy in food is transferred from plants to consumers.

Heat (b) Using energy to do work When energy is used to do work, some energy is converted to thermal energy, which is lost as heat. An animal’s muscle cells convert chemical energy from food to kinetic energy, the energy of motion. A plant’s cells use chemical energy to do work such as growing new leaves.

Theme 4 □Structure and function are correlated at all levels of biological organization. □The form of biological structure suits its function and vice versa

Theme 5 □The cell is an organism’s basic unit of structure and function □All cells have a cell membrane and DNA □Eukaryotic vs prokaryotic

□A eukaryotic cell has membrane- enclosed organelles, the largest of which is usually the nucleus □By comparison, a prokaryotic cell is simpler and usually smaller, and does not contain a nucleus or other membrane-enclosed organelles

Eukaryotic cell Cytoplasm Nucleus (membrane- enclosed) Membrane Membrane- enclosed organelles DNA (throughout nucleus) 1  m

Prokaryotic cell DNA (no nucleus) Membrane 1  m

Theme 6 □The Continuity of Life Is Based on Heritable Information in the Form of DNA □Chromosomes contain most of a cell’s genetic material in the form of DNA (deoxyribonucleic acid) □DNA is the substance of genes

□ Genes are the units of inheritance that transmit information from parents to offspring □The ability of cells to divide is the basis of all reproduction, growth, and repair of multicellular organisms

Sperm cell Nuclei containing DNA Egg cell Fertilized egg with DNA from both parents Embryo’s cells with copies of inherited DNA Offspring with traits inherited from both parents

Nucleus DNA Cell Nucleotide (b) Single strand of DNA A C T T A A T C C G T A G T (a) DNA double helix A Figure 1.11

□Genes control protein production indirectly □DNA is transcribed into RNA then translated into a protein □(Central Dogma) □ Gene expression is the process of converting information from gene to cellular product

Genomics: Large Scale □An organism’s genome is its entire set of genetic instructions □The human genome and those of many other organisms have been sequenced using DNA-sequencing machines □ Genomics is the study of sets of genes within and between species

Theme 7 □Feedback Mechanisms Regulate Biological Systems □Two versions: □Positive □Negative

Positive or Negative? □For example, insulin... high levels of glucose in the blood trigger the release of this hormone. It triggers cells (especially in the liver and skeletal muscle) to take up and store sugar from the blood. Result? Less sugar in the blood.

Positive or Negative □A prime example is the hormone oxytocin. Its release is stimulated by a baby's suckling at a mother's breast. It causes the "letdown" reflex, so milk is released to the baby. The baby tastes the milk, thinks, "Yum! That's good!" and suckles more... which causes more oxytocin release, which causes more milk release... etc.

Figure 1.13 Negative feedback A B C D C Enzyme 1 Enzyme 2 Enzyme 3 D W Enzyme 4 X D D Excess D blocks a step. (a) Negative feedback Positive feedback Excess Z stimulates a step. Y Z  Z Z Z (b) Positive feedback Enzyme 5 Enzyme 6