Benefits of models
1. Represents large and small
2. Represents complex and simple
3. Explain how something works
4. Make predictions
Limitations of models
Different from actual thing
Law vs Theory
Law: summary of many experiments. Statement guaranteed to happen and based on facts, cannot be changed
Theory: hypothesis, used to predict what might happen, broad range of observations
Gregor Mendel
discovered the principles of heredity while studying pea plants
Robert Hooke
First person to describe cells
Charles Darwin
English natural scientist who formulated a theory of evolution by natural selection (1809-1882)
Anton von Leeuwenhoek
Inventor of the first microscopes. 1600's.
First saw organisms in water and called them animalcules
International System of Units
System that helps scientists share and compare observations and results. Metric System (kilo, meter, liter, gram, milli, centi, deci)
Steps of the Scientific Method
1. Identify problem
2. Learn about the problem
3. Hypotheses (based on observation and must be testable)
4. Testing your hypothesis/experiment (analyzing data)
5. State conclusion
Define variable
A factor changed in an experiment
Changed variable (Independent)
What is changed or tested during an experiment
Measured variable (Dependent)
What is being measured during an experiment
Controlled variable
What stays the same or constant during an experiment
Control groups
The group that receives no treatment and is used for comparison
Characteristics of All Living Things
1. have cells
2. sense and response to change
3. reproduce
4. have DNA
5. use energy
6. grow and develop
Cells
Smallest unit of life
Tissue
Group of cells acting together
Organs
Group of tissues acting together
Organ system
Organs working together
Organism
Organ systems working togther
Single celled organisms
Composed of only one cell (bacteria, fungus, and protists)
Multi-cellular organisms
1. organism made up of many cells
2. able to be of larger size
3. able to live longer
4. cells are able to specialize
Benefits to being multi cellular
Able to be larger, live longer, cells have particular job (specialization)
Cell Theory
1. All organisms are made of one or more cells
2. The cell is the basic unit of all living things
3. All cells come from existing cells
Plant cells
1. Have a cell wall and chloroplasts/chlorophyll.
2. Make their own food, take in CO2 and give off O2
3. Have a large central vacuole
Animal cells
1. lacks cell wall (not needed)
2. lacks chloroplasts/chlorophyll
3. many small vacuoles
4. takes in O2 gives off CO2
5. contains lysosomes
Main Parts of a compound light microscope
1. Body tube with 2+ lenses
2. Stage
3. Light source
Photosynthesis
How plants produce food
Plants use the energy captured by chlorophyll to change CO2 and water into glucose (food in sugar for,) and o2 is produced
CO2+H2O+Light Energy=Glucose (sugar)+o2
Cellular respiration
the process by which cells use oxygen to produce energy from food (in mitochondria)
Glucose (sugar)+ O2= Co2+h2o+energy
Homeostasis
the process by which organisms maintain a stable internal environment (ex. Body Temp)
Stimulus
Anything that causes a reaction to an organisms
Response
How the organism reacts to a stimulus
What is a dochotomous key used for?
An aid that is used to identify organisms and consists of a series of paired questions
Animalia Kingdom
1. Eurkaryotic Cells
2. Multicellular
3. No cell wall
4. Usually able to move
5. Have sense organs
6. Meed O2
7. Must rely on other organisms for food (can't make or decompose food on its own)
Plantae Kingdom
1. Eukaryotic cells
2. Have cell walls
3. Make own food through Photosynthesis
4. Need CO2
Protista Kingdom
Eukaryotic cells, signle celled or very simple multicellular organisms
Abiotic
Non-living part of an enviorment (rocks, water, temp, light, etc)
Biotic
Living parts of an environment (plants, animal, etc)
Ecosystem
includes all the biotic and abiotic factors found in an area
A community of organisms and their environment
Negative effects people have on ecosystems
1. pollution
2. nonrenewable resources
3. introducing new species
4. habitat destruction
Population
A group of individuals that belong to the same species and live in the same area
Producer
An organism that can make its own food using sunlight (plants)
Consumer
An organism that obtains energy by feeding on other organisms (animal)
Decomposer
An organism that get energy by breaking down waste and dead organisms (bacteria and fungus)
Predator
An animal that hunts other animals for food
Prey
An organism that is killed and eaten by another organism
Parasite
A symbiotic relationship in which an organism benefits while the other is harmed
-the organism that benefits
Host
An organism on which a parasite lives/harmed by parasitism.
Gene
One set of instructions for an inherited trait
Exceptions to Mendel's principle
1. One gene can influence more than one trait
(White tiger-blue eyes)
2. Sometimes several genes work together to influence a trait (skin color, hair color, eye color)
3. The environment can affect traits (good diet)
Chromosomes
Long strand of DNA (humans have 46)
Dominant trait
a genetic factor that blocks another genetic factor
The trait that appears in the first generation. The stronger trait
Recessive trait
a genetic factor that is blocked by the presence of a dominant factor
That trait that is hidden and seems to disappear in some generations
Explain how traits are influenced and passed from one generation to the next
Traits are passed down through heredity, and are influenced by their environment.
Use a punnet square by
Lining up alleles
Human cells have _____ chromosomes
46 (23 pairs)
Sex cells have how many chromosomes?
23 total
Each parent gives half number of chromosomes to the child
Asexual reproduction
Process by which a single parent reproduces by itself
Sexual reproduction
type of reproduction in which cells from two parents come together to form the first cell of a new organism
Advantages and Disadvantages to Sexual and Asexual Reproduction
Sexual Reproduction- produce offspring similar to self. There is diversity
Asexual reproduction- each generation is exactly same, able to reproduce quick
Adaptation
Changes in behavior or in physical appearance that takes place over time in response to changes in the environment
Natural selection
The process by which individuals are better adapted to survive and reproduce more sucessfully (Darwin) otherwise known as the survival of the fittest
Overproduction
A condition in which production of goods exceeds the demand for them
Evolution
Process where population slowly changes over time
Extinction
When a species dies out completely
Fossils
Traces of living things that are preserved in rocks
Why are fossils important evidence for evolution?
They show how organisms have developed and changed over time.
Pathogens
virus, bacteria, fungi, protists, or worms that causes disease
Cancer
any malignant growth or tumor caused by abnormal and uncontrolled cell division
Is cancer a pathogen
NO, cancer is the condition where cells divide at an uncontrollable rate while pathogen is something that can cause a disease to occur
Noninfectious disease
A disease that cannot spread from one individual to another
(Genetic disorder/not contagious)
Infectious disease
A disease that is caused by a pathogen and that can be spread from one individual to another.
Specialized cells
1. red blood cells (carry o2)
2. white cells (fight pathogens)
3. nerve cells (carry messaged to from brain)
4. bone cells (provide support)
5. muscle cells (contrast and relax)
Types of models
1. Physical (cell model)
2. Mathematical (Punnet Square)
3. Conceptual (ideas and hypothesis)
Digestive System main organs and functions
Mouth- takes in stuff
Teeth/tongue- mechanical digestion
Salivary glands-start chemical digestion
Esophagus- pushes food to the stomach
Stomach- grinds food
Small intestines- molecules are absorbed into the bloodstream
Large intestines- excess water is re
Cardiovascular System main organs and functions
Heart- made of cardiac muscles and pumps blood
Blood- carries o2 nutrients and wastes, and helps regulate temp
Arteries- carries blood away from the heart
Veins- carries blood to the heart
Capillaries- allow exchange between the blood cells and the body c
How is energy transferred through a food web?
Energy is transferred through the separate levels of a food chain or web by feeding.
How do technology and scientific knowledge influence each other?
1. Find information and get results in new ways.
2. Allows us to see inside organisms in new ways.
key term is "new way
Different types of cell division
1. binary fission (prokaryotic cells)
2. mitosis/meiosis (eukaryotic cells)
Steps of Mitosis
1. Interphase
2. Prophase
3. Metaphase
4. Anaphase
5. Telophase
6. Cytokinesis
Why do cells divide?
1. they can not grow any larger
2. repair/replace damaged cells
3. reproduction or growth
Why are the systems of the human body so important?
They all work together to keep homeostasis. In other words, they all work together to keep us alive.
Different systems in the human body
There are a total of 12.
1. Integumentary (skin, hair, nails)
2. Muscular (helps us move by working w/skeletal system)
3. Skeletal (support/protect body parts)
4. Cardiovascular/Circulatory (heart pumps blood through all blood vessels)
5. Respiratory (lun
Why do scientists use models?
Scientists use models to help explain how something works or to describe how something is structured.