Presentation on theme: "New York State Intermediate Science Review Mr. Amidon NAME ____________________ The Living Environment Life Science The Physical Setting Earth ScienceChemistry."— Presentation transcript:
New York State Intermediate Science Review Mr. Amidon NAME ____________________ The Living Environment Life Science The Physical Setting Earth ScienceChemistry Physics Energy
Cells The Cell Theory states that: living things are composed of cells. cells are the basic unit of structure and function of living things. all cells come from other cells.
Types of Cells Prokaryotic Simple; no nucleus or organelles Bacteria Eukaryotic Larger, more complex Many organelles Found in Animals, Plants, Fungi, & Protists These are the “cells” you think of
Cell Organelles Cell Membrane- surrounds the cells and controls entry and exit Cytoplasm- the region between the cell membrane and the nucleus; Liquid material that contain the organelles of the cell. Nucleus- The "brain" of the cell. Contains the chromosomes. Chromosomes- Information center of the cell. Contain most of the genes, which are made up of DNA.... Ribosome- helps to build proteins. Endoplasmic Reticulum – transports proteins Golgi Bodies- packages proteins Mitochondria-Cellular respiration. Energy is produced. Vacuole- storage center. Both wastes and nutrients. Lysosomes- controls the enzymes that break down protein. Not Found in Animal Cells Cell Wall- provides support and helps to protect planet cells. Chloroplasts- found only in plant cells. Contains chlorophyll, which transforms CO 2 and light energy into food and O 2.
In Photosynthesis: Energy is used to create sugars Carbon Dioxide & Water are Reactants Oxygen in a Product In Respiration: Energy is released when sugars are broken down Food and Oxygen are Reactants Carbon Dioxide & Water are Products Photosynthesis & Respiration are Opposite Reactions
Cell Organization Organelles do life functions for individual cells In multicellular organisms, life functions need to be taken care of as a whole Cells are become specialized & organized Groups of cells with similar functions are TISSUES Groups of tissues are ORGANS Organs that work together form ORGAN SYSTEMS
Body Systems Digestive Break down food Endocrine Chemical signals through hormones Nervous Electrical signals Immune Fight disease & infection Circulatory Transport food & wastes
Body Systems Excretory Remove waste Muscular & Skeletal Movement, support, & protection Respiratory Cycle Oxygen in, Carbon dioxide out Reproductive Specialized cell division (meiosis)
Cell Division Cells split two different ways Mitosis Creates an exact replica of the original cell (clone) Most unicellular organisms reproduce this way Happens all the time in your body Meiosis Results in a cell with only ½ of the regular chromosomes Only happens in sexually reproduction
Structure of DNA
Cancer Caused by change in DNA structure MUTATION Uncontrolled cell division Produces too many cells, may not replicate correctly Produces a tumor Mass of cell created when cell divide and grow uncontrollably IF a cell from a tumor breaks off and begins growing in a new area, cancer can be spread (metastasis)
Reproduction Asexual Involves one parent Usually, offspring have exactly the same genetic information as the parent. This only changes if there is a mutation. TYPES Plants – runners, roots, grafting Animals – budding Protists/ Bacteria – Fission (Binary) Sexual Involves two parents (usually) Genes are mixed Creates offspring different from parents SPECIES BENEFITS DUE TO VARIATION Less likely that one disease can wipe out a whole population
Fertilization & Development
Genetics Discovered when Gregor Mendel crossed pea plants Sexual Reproduction produces variation because genes come in pairs (1 copy from mother, one copy from father) Genes represent features seen in organisms Dominant genes (brown eyes, tall pea plants) are always expressed if they are present Recessive genes (blue eyes, short pea plants) show only if the organism has two copies Allow different traits to be seen in offspring If traits help offspring survive, the trait is passed on Peppered Moths
Punnett Square Capital represents dominant gene (T = tall) Lowercase is recessive (t = short) Each parent has two copies & all offspring have two copies, but ONLY ONE COMES FROM EACH PARENT! TT = Homozygous tall tt = Homozygous short Tt = Heterozygous tall *Sometimes hybrids are mixes, like white flowers crossed with red flowers to make pink flowers This is incomplete dominance Used to predict percentages of offspring with certain traits TT tTt t 0% will be Homozygous tall 0% will be Homozygous short 100% will be Heterozygous tall Tt T t _____ will be Homozygous tall _____ will be Homozygous short _____ will be Heterozygous tall
Nutrition Food provides fuel and building material. All organisms release energy from food to carry out life functions. Food contains nutrients, vitamins, carbohydrates, fats, proteins, minerals and water. All of the above are necessary for survival of the organism. Metabolism is the total of all chemical reactions. Your metabolism can be affected by your hormones, exercise, diet and aging. Food energy is measured in calories. Each organism requires a different amount of calories. In order to maintain homeostasis all organisms need a minimum daily requirement of calories A change in caloric intake can cause weight loss/gain or disease. Infectious disease, behavior and use of toxic substances can cause a change in homeostasis. During pregnancy these changes can affect the development of the child. Some of these changes can affect your body immediately or may take years to develop.
Energy Through Ecosystems All energy for living things comes from the Sun originally Green plants and other organisms with chlorophyll carry out photosynthesis. The sun's energy in converted into sugar. The amount of sugar present in a green plant increases with more sun light. Photosynthesis provides the atmosphere with a major source of oxygen. Photosynthesis removes carbon dioxide from the atmosphere. Green plants are producers. Energy from green plants is used by consumers directly or indirectly. Energy needs to be inputted from the Sun everyday!
Ecosystems Population- all individuals of a species that live together. Community- all populations living together in a particular area. Ecosystem- the community and the physical factors with which it interacts. All biotic and abiotic factors Energy enters the ecosystem by the sun through green plants. The process of photosynthesis converts sunlight into energy. A food chain:
Food Web Interconnected food chains. Matter is transferred from one organism to another and between organisms and the environment.
Nutrient Cycles Energy is not cycled! It is lost to the environment!
Energy Pyramids Energy is lost in a ecosystem The green circle represents the producer. All of the stored energy in the body of the producer organism is eaten by the primary consumer. The second circle represents the primary consumer. Only the stored energy is eaten by the secondary consumer. The third circle above represents the secondary consumer. Only a very small fraction (shown in green) of the producer's original energy is stored by the secondary consumer. This energy is taken into the body of the tertiary consumer. As the energy is passed along the food chain much of it is either used or lost. Therefore there is a limit to the number of organisms in a food chain. The top carnivore is usually the third or fourth consumer.
A = plankton, B = shrimp, C = fish, D = seagull
Niche & Habitat The habitat must supply the needs of organisms, such as food, water, temperature, oxygen, and minerals. If the population's needs are not met, it will move to a better habitat, or the population will not survive. An organism's niche is their role in the ecosystem. If a habitat describes where an organisms lives, niche describes what an organism does for a living. A niche is defined by the way the organism interacts with the living and nonliving components of its ecosystem - what it eats, the habitat it prefers, etc. Different species could occupy similar niches in different, separate habitats. Organisms are basically classified on the basis of their niche as decomposers, consumers, or producers. The niche of a tuna within its ecosystem is that of top predator because it eats other animals and nothing eats it. In that same ecosystem, a crab would be an omnivore because it eats both plants and animals, and bacteria would be a decomposer.
Relationships Between Species Two different populations can not occupy the same niche at the same time, so the processes of competition, predation, cooperation, and symbiosis occur. Parasitism Parasitism – when two organisms live in a way that helps one species survive, while harm is done to the other Commensalism Commensalism – when two organisms live close together and one species benefits, but the other really is not affected Mutualism Mutualism – two organisms live close together and both species benefit. However, the survival of one species does not depend on the other. Pollination of plants by insects, birds & bats Symbiosis Symbiosis – two or more organisms live so close together that they can not survive without the other organism Lichens
Survival of the Fittest In order for an organism to survive, they must overcome many obstacles: Predation – some species are food for other species Competition - Organisms within an environment may compete for resources such as food or shelter. The strongest organisms would gain the resources and survive to reproduce. If one species out-competes another species in the area, this could lead to wiping out an entire species. (Extinction) Disease – parasites that weaken the organism, or cause death Change in Environment – sometimes resources change and the species must be able to find new food sources or move to a location they can survive in Adaptation –the development of new traits that are advantageous and help the organism escape predators, or find food better, or survive diseases, or out-compete other organisms for food supplies Physical = the development of a certain body part that helps the organism survive (Giraffes long necks) Behavioral = the change in a behavior to help the organism survive (Many animals are active at night because some predators have a hard time seeing in the dark)
Evolution Proposed by Charles Darwin Explains how natural selection produces offspring that are not the same as the generations that come before it. Adaptations that help individuals survive will show in offspring because they are more likely to reproduce Evolution is “powered” by genetic mutations. These are changes in the DNA that cause new traits to be seen. Mutations are not always bad! If trait helps organisms compete, trait will be passed on. Eventually, enough new traits can be passed on so that offspring do not look like ancestors. If these descendants are so different from the original species, then a new species have developed. It evolved from the old species. Evolution does not happen in one day, it can only be seen as a progression over many generations
Evolution of the Horse
Ecosystems in Flux In ecosystems, balance is the result of interactions between community members and their environment. The environment may be altered through the activities of organisms. Alterations are sometimes abrupt. Some species may replace others over time, resulting in long-term gradual changes (ecological succession). Extinction can happen if environments change too quickly for members of an ecosystem. Overpopulation by any species impacts the environment due to the increased use of resources. Human activities can bring about environmental changes through resource acquisition, urban growth, land-use decisions, waste disposal, etc.. Since the industrial revolution, human activities have resulted in major pollution of air, water, and soil. Pollution has cumulative ecological effects such as acid rain, global warming, or ozone depletion. the survival of living things on our planet depends on the conservation and protection of Earth's resources.
Classification Kingdom, Phylum, Class, Order, Family, Genus, Species Carrolus Linneaus Developed two-part naming system (Genus & species) Based on structures & characteristics Calypte anna