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LIFE SCIENCES. CHARACTERISTICS OF LIVING THINGS. Organisms are HIGHLY ORGANIZED . All organisms are made up of the same basic components, kind of building blocks: CELLS. (ORGANISM is an entire and independent living thing)
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CHARACTERISTICS OF LIVING THINGS • Organisms are HIGHLY ORGANIZED. All organisms are made up of the same basic components, kind of building blocks: CELLS. (ORGANISM is an entire and independent living thing) • CELLS ARE THE UNIT OF STRUCTURE AND FUNCTION OF LIVING THINGS. CELLS CONTROL AND REGULATE THEIR OWN ACTIVITY.
CHARACTERISTICS OF ALIVE BEINGS • They have a complex, organized structure mainly made of organic molecules. • They respond to stimulation from the environment that surrounds them. • They keep actively their complex structure and their intern environment; this process is called homeostasis. • They obtain and use materials and energy of it’s environment and turn them in different forms. • They grow. • They reproduce, using a molecular pattern called DNA. • They generally posses the capacity to evolve and adapt.
IRRITABILITY: Organisms respond to stimuli in different ways.
REPRODUCTION: Process by which organisms produce more of their own.
HOMEOSTASIS • Organisms are able to maintain a nearly constant internal environment, although the surrounding may change. Homeostasis is the regulation of an organism’s internal environment to maintain conditions suitable for life.
KIND OF CELLS Prokaryotes • Prokaryotes are organisms without a cell nucleus, or any other membrane-bound organelles. Most are unicellular, but some prokaryotes are Multicellular organisms. • The prokaryotes are divided into two domains: the bacteria and the archaea. Archaea or Archaebacteria are a newly appointed kingdom of life. These organisms were originally thought to live only in inhospitable conditions such as temperature, pH-extremes, and radiation, but have since been found in all types of habitat. From Old Greek pro - before + karyon nut or kernel, referring to the cell nucleus, + suffix –otos.
Eukaryotes from the Greek ευ, meaning good/true, and κάρυον, meaning nut, refering to the nucleus • Animals, plants, fungi, and protists are eukaryotes, organisms whose cells are organized into complex structures by internal membranes and a cytoskeleton. The most characteristic membrane bound structure is the nucleus. In the nucleus the genetic material, DNA, is arranged in chromosomes. Many eukaryotic cells also contain membrane-bound organelles such as mitochondria, chloroplasts and Golgi bodies. Eukaryotes often have unique flagella made of microtubules in a 9+2 arrangement.
DNA • Short for Deoxyribonucleic acid • All genetic information as well as the instructions for making proteins is contained here • Its structure was discovered by James Watson and Francis Crick
DNA structure • Is composed of two strands of nucleotides forming a double helix • Nucleotides are composed of a simple sugar called deoxyribose, a phosphate group and a nitrogen containing base.
CONCEPTS • Concentration gradient: difference in concentration of a substance between one region and another • Diffusion:process by which molecules move randomly from regions of high concentration to regions of low concentration • Osmosis:movement of water through a differentially permeable membrane. Responds to concentration gradient
How does substances move across membranes? • Passive transport:Substances move down concentration gradient. There’s no energy expenditure. • Active transport.Use energy to move substances againsta concentration gradient
Osmosis • “Pure” water has higher concentration of water molecules than other water solution with any substance added. • A differentially permeable membrane has pores just large enough for water to pass through but small enough to be impermeable to any other molecule.
What is a Population? • A population is one species living in a specific area. • For example, all foxes living in an area form a population. • Another example, all dandelions growing in an area form another population.
What is a Community? • A community is formed from all living populations found in an area. • All the foxes, dandelions, grasshoppers, snakes, hawks, deer, and skunks living in one area each form their individual populations, but together make up a community.
What is a Ecosystem? • An ecosystem is formed by the interactions between all living and non-living things What is Ecology? Ecology is how living and non-living things affect each other in their environment.
