Science Review Flashcards
Science Flashcards that are always checked each week.
What are in a plant cell?
One large vacuole
Chloroplast
Cell Wall
Limited movement
CELL MEMBRANE
What are in an animal cell?
Many small vacuoles
No Chloroplast
No cell wall
Cells can move around
CELL MEMBRANE
What is a cell wall?
A cell wall provides structure and support to the plant and it is like a skeleton to the plant.
What is the Body Organization (sequencing)?
Cell = Tissue = Organ = Organ system = Organism
Simple to Complex
What is a cell?
A cell is the basic unit of life.
What is a tissue?
A tissue is a group of cells that performs the same function. (An activity which does the same thing)
What are the types of tissues?
Muscle tissue, nervous tissue, connective tissue, epithelial tissue (= covering; skin and organ lining
What is an organ?
It contains different tissues that perform a specific function. Ex. Heart - It pumps blood; Ex. Stomach - It breaks down solid food.
What is an organ system?
It is a group of different organs working together to perform a major (complex) function.
What are the types of organ systems?
Skeletal, Muscular, Digestive, Circulatory, Lymphatic, Respiratory, Excretory, Nervous, Endocrine, Reproductive, Immune
Ex. Circulatory System - It transports materials to (nutrients) and from (waste) body cells.
What is an organism?
Made up of different organ systems that perform a function.
What are invertebrates?
No backbone. No skeleton or external skeleton called an exoskeleton.
What are vertebrates?
Internal skeleton called an endoskeleton, backbones (vertebral column).
What are the common features between vertebrate and invertebrate animals?
They both live on Earth.
They both are composed of cells.
They both have a life cycle (birth, growth, reproduction, and death)
What does classified mean?
Grouping by similar characteristics.
How are animals classified?
Animals are classified according to how they are related to other animals. These relationships are determined by an animal’s body structure, the way the animal develops, and its DNA.
What are the functions of animals?
The major functions of animals are to obtain food and oxygen, keep internal conditions stable, move, and reproduce.
How do animals obtain food?
An animal cannot make food for itself - it obtains food by eating other organisms.
Why is movement important for animals?
Animal movement is required for survival and reproduction.
What is sexual reproduction?
Sexual reproduction is the process by which a new organism develops from the joining of two sex cells - a male sperm cell and a female egg cell.
What is asexual reproduction?
Asexual reproduction is the process by which a single organism produces a new organism identical to itself.
What are the 3 types of Animal Symmetry?
Asymmetry, Radial and Bilateral symmetry.
What is symmetry?
The balanced arrangement of parts is called symmetry.
What is asymmetry?
No symmetry; example: sponge
What is radial symmetry?
Many lines that all go through a central point; example: starfish
What is bilateral symmetry?
A line dividing organisms into halves that are mirror images; example: fish, amphibians, reptiles, mammals (humans).
Why are sponges/cnidaria, worms, mollusks, echinoderms grouped together?
Sponges/cnidaria, worms, mollusks and echinoderms are grouped together because they have no skeletons.
Why are fish, reptiles, and amphibians grouped together?
They grouped together because they are cold blooded or ectotherms→get heat from the outside.
Why are birds and mammals grouped together?
Birds and mammals are grouped together because they are warm blooded or endothermic → get their heat from inside their body.
What is a sponge (=porifera)?
Porifera to have pores - Eukarya (Animal Group) = multicellular they use oxygen in order to survive, they need nutrients for survival, they are: asymmetrical, no tissue, no organs, no organ system cells (oxygen,food) filter feeders. They have spikes for self defense. Sponges reproduce both asexually (budding) and sexually (larva).
What is Cnidaria?
Cnidaria = Sea Anemone = Jellyfish - they have two body plans (polyp, medusa), they have radial symmetry, they have a central hollow cavity, they have tentacles with stinging cells (it captures food, also for defense.) Cnidaria reproduce both asexually (budding) and sexually.
What is a coral reef?
A coral reef is built by cnidarians and is home to many fishes and they are invertebrates.
What are some worm characteristics?
Invertebrates. Some worm characteristics are that they have long, narrow bodies without legs. Cylindrical. *They have tissues, organs, an organ system present. *They are the first to have a simple brain; it is a bundle of nerve tissue. They have bilateral symmetry.
What are the 3 types (phyla) of worms?
Flatworms (Platyhelminthes), Roundworms (Nematoda), Segmented Worms (Annelida)
What are flatworms (Platyhelminthes)?
Flatworms (Platyhelminthes) are flat, soft (jelly-like). They are either parasites or free living organisms.
What is a parasite?
A parasite is an organism that lives inside an animal or on another organism.
What is the lifestyle of a parasite?
They live inside another organism and gets food from host’s body fluids. Ex. Tapeworm and flukes
What are planarians?
They are free living flatworms and feed on dead or decaying material (scavengers). They rely on smell not light to locate food. They can also be predators that attack smaller prey.
What are roundworms (Nematoda)?
The first - like the digestive system (mouth and anus) They have a cylindrical body.
What are segmented worms (Annelida) ?
They are segmented, cylindrical bodies (a series of rings separated by grooves). They have the first tube - like the digestive system (mouth and anus). *They have the first nerve cord (pre - spinal cord) “Pre Vertebrate”. *They are also the first closed circulatory system.
How do earthworms help the soil?
Earthworm tunnels loosen the soil, allowing air, water, and plant roots to move through it. Earthworm droppings make the soil more fertile.
What are the differences between a mollusk and a worm?
A mollusk has a soft body with or without shell, mantle, foot, and open circulatory system. Meanwhile a worm has a soft body, no mantle, no foot, and a closed circulatory system.
What is a mollusk?
It has a soft body (unsegmented), with or without a hard outer shell, they have a mantle ( it has a covering internal organs and secretes shell), they have a foot, they have an open circulatory system. They have bilateral symmetry. They also have a digestive system with two openings. They have gills. Ex. Clams, oysters, scallops, snails, mussels, squid, octopus, cuttlefish.
What are the three major groups of mollusks?
Gastropods, bivalves and cephalopods are the three major groups of mollusks.
What are gastropods?
Snails or slugs, Radula (Teeth), Foot (Creeping foot moves on slippery mucus), with or without a shell. Some gastropods are herbivores, carnivores, or scavengers.
What are bivalves?
Bivalves have two shells held together by hinges and strong muscles and they are filter feeders. Most are omnivores. Ex. Clams, scallops, oysters, and mussels.
What are cephalopods?
They have tentacles (modified foot), they swim by jet propulsion, with or without shell, closed circulatory system, complex nervous system, large brain: intelligent, excellent vision. They are carnivores. Ex. Octopus, squid, cuttlefish and nautilus
What are the characteristics of Arthropods?
Arthropods are invertebrates that have an external skeleton, a segmented body, and jointed attachments called appendages (wings, mouthparts, legs). Bilateral symmetry, open circulatory system, digestive system with two openings, and they reproduce sexually.
How are arthropods classified (4 groups)?
Crustaceans, Arachnids, Insects, Centipedes, Millipede
What is the function of the exoskeleton?
All arthropods have a hard exoskeleton. It is a waxy covering which is a protective armor and prevents it from drying out. They can shed their exoskeletons (molting) and grow new ones.
What are Crustaceans?
C5 - 5 or more pairs of legs. Mostly marine; very few on land.
A crustacean is an arthropod that has two or three body sections, five or more pairs of legs, and two pairs of antennae. They have gills. Some are scavengers other are predators.
What are Arachnids?
A24 - 2 body sections and 4 pairs of legs. They live on land, dry areas, and hot climates.
Arachnids are arthropods with two body sections, four pairs of legs, and no antennae. They are predators.
What are Centipedes?
C1N - 1 pair of legs per segment; more than 100 segments.
Centipedes are arthropods with two body sections and many pairs of legs. They are predators.
What are Millipedes?
M2N - 2 pairs of legs per segment; more than 80 segments.
Millipedes are arthropods with two body sections and many pairs of legs. They are scavengers.
What are Insects?
I33W - 3 pairs of legs, 3 pairs of legs, 1 pair of antennae, 1 or 2 pairs of wings. They are the most diverse arthropod group (in body shape and mouth parts; adaptations for survival)
What are the three sections of an insect’s body?
- Head - Two large compound eyes and antennae.
- Thorax - Wings and legs are attached.
- Abdomen - Internal organs.
How do insects obtain food?
Insects mouthparts are adapted for a highly specific way of getting food.
Sponge like mouthpart to lap up decaying flesh.
Coiled tube to suck nectar.
Sharp edged to cut through seeds, wood, other foods.
What is insect biodiversity?
Adaptations = Environment
Physical Feature = Survive (Successful)
Explain why insects are important to scientific investigations?
Insects are the most diverse arthropod.
What is metamorphosis?
It is the change in form or shape.
What is complete metamorphosis?
Egg, larva, pupa, adult are the four stages.
The juvenile (baby) stages (larva,pupa) that look different from the adult.
What is gradual metamorphosis?
Has no distinct larval stage. Egg, nymph, adult insect without wings, adult.
The juvenile (baby) stage (nymph) is a miniature of the adult.
What characteristics do echinoderms have?
Echinoderms are invertebrates with an internal skeleton and a system of fluid - filled tubes called water vascular system. They have radial symmetry. They reproduce sexually.
What are the four major groups of echinoderms?
Sea stars, brittle stars, sea urchins, and sea cucumbers are the four major groups of echinoderms.
What are tube feet and it’s function?
The sticky tube feet line the underside of a sea star’s arm and act like tiny suction cups.
Echinoderms use their tube feet to move slowly and to capture food.
What is the function of the water vascular system?
The function of the water vascular system is that it helps the sea star to move and catch food.
What is a chordate?
1) It has a notochord - it is a flexible rod —- it evolved into the vertebral column.
2) Nerve cord - it is a string that transmits a nerve signal —— it evolved into a spinal cord.
3) Pharyngeal Gill Slits - ——— it evolved into gills (Fish, amphibians, and tadpoles)
What is a vertebrate?
1) Backbone (Vertebral Column with a spinal cord) 2) Endoskeleton (inside skeleton)
What is an ectotherm?
An animal whose body temperature is close to the temperature of their environment; its body does not produce much internal heat; they are cold - blooded
What is an endotherm?
An animal whose body temperature is stable and often warmer than their environment; its body regulates its own temperature by controlling the internal heat it produces; they are warm blooded.
What are fish?
They are cold - blooded, they have fins, they have scales, they have gills, they mostly external fertilization, they have a closed circulatory system, they have a 2 chambered heart, and they are the oldest and largest vertebrate group.
What is fish classification?
There are three groups the Jaw-less fish (agnatha), Cartilaginous Fish (Chondrichthyes), and Bony Fish (Osteichthyes).
What is a Jaw-less Fish?
Cartilage skeleton, no jaws and no scales.
Ex. Hag-fish and Lampreys
What is a Cartilaginous Fish?
Cartilage skeleton, jaws and scales. Ex. Sharks, rays and skates.
What is a Bony Fish?
They have a bony skeleton, jaws and scales gill pocket with flap and a swim bladder (internal gas-filled sac). Most fish (95%) are bony fish. Ex. Trout, tuna and goldfish
What is an amphibian?
They are endothermic, they are cold-blooded. Their juvenile life lives in water and uses gills, they move with fins and they have 1 loop circulatory system, they have a 2 chambered heart, they are herbivores. When they are adults they live on land, they have lungs, but they reproduce in water; thin, moist skin, they move with skeleton muscle, they leap, they have a 2 loop circulatory system, 3 chamber heart, they can camouflage, they are carnivores.
What are the three groups of amphibians?
Frog/toad, (loss of tail), external fertilization, Salamander/newts (tail), internal fertilization, Caecilians (no legs, and no scales).
Are amphibians from water to land threat of extinction?
Population decline due to: 1] habitat destruction 2] pesticides / chemical pollutants – harms delicate skin, tadpole mutations, kills
What is a reptile?
They are ectothermic, cold - blooded, lungs, scales that cover skin, they have a 3 chamber heart except alligators who have 4 chambers. First True land lifestyle adaptations to conserve water they have skin with scales for protection, it prevents evaporation, they have kidneys (concentrated urine-liquid waste), amniotic egg, a leathery shell with internal membranes, and they have internal fertilization.
Ex. Snakes, lizards, turtles, alligators, crocodiles, dinosaurs (extinct).
What is a snake?
Overlapping scales, shed scaly skin, they live in a warm environment. No legs, streamline body, no ears, no eyelids, 1 lung; carnivores; they slither by muscle contractions.
What is a lizard?
Overlapping scales, shed scaly skin, they live in a warm environment. 4 legs with clawed toes, tail, ears, eyelids, 2 lungs; most carnivores; walk/run.
What is an alligator?
Largest living reptiles, nocturnal carnivores, first living “they care for young” behavior. Broad, rounded snout, few teeth (mouth closed); max size : 15ft, 1000lbs
What is a crocodile?
Largest living reptiles, nocturnal carnivores, first living “they care for young” behavior. Tapered, pointed snout; pencil-like; many teeth (mouth closed); max size: 17-20 ft, 2300 lbs
What is a turtle?
They have shells (with ribs and backbone) made of fused scales, they have a beak, they are herbivores and carnivores.
What is a dinosaur?
They are the earliest vertebrates with legs directly beneath their bodies, they are ectotherms or first endothermic, first “care for young behavior” Extinction: 65 yrs ago due to asteroid impact in NE Mexico.
What is a bird?
They are endothermic (warm blooded) they maintain constant body temperature by food and feathers, they have feathers, they have hollow bones, they have air sacs, they are the first major group with a 4 chamber heart it (prevents mixing of O2 rich and O2 poor blood) their eggs have hard shells, they “care for young” behavior (feed and protect until young able to fly), they have internal fertilization.
How do birds obtain food?
Birds have bills to tear and strain, they have a crop internal storage tank, they have a two part stomach the first part breaks down chemicals and the second part is called the gizzard which has physical breakdown with stones (gastroliths).
How do birds originate?
Birds are believed to be descended from Archaeopteryx (a reptilian dinosaur with wings and feathers)
What are mammals?
They are endothermic - warm blooded, they have a 4 chambered heart, they have fur or hair, they have breasts(mammary glands, milk), they “care for young” behavior, they have lungs with diaphragm, they have an advanced nervous system (complex brains from problem solving), and they have highly developed senses (large eyes, sonar, smell sensitivity.
What are teeth adaptations?
Incisors: cut, canines: they tear, and slashing, and they have molars that grind.
What are cold environment adaptations?
To keep warm, food (higher in calories, meat or fish. They have fur, hair and fat.
What are movement adaptations?
Mammals walk, run, hop, swing, glide and swim.
What are Monotremes?
they lay eggs (primitive).
Ex. Spiny anteater, and duck - billed platypus.
What are marsupials?
They are partly developed young live in a pouch.
Ex. Koala bear, Kangaroo and Opossum
What are Placental Mammals?
It develops inside mothers body; diverse, subdivided based on eating and movement. Ex. Carnivores (eat meat), marine (swim), rodents (gnaw), rabbits/hare (hop), trunk, insect eaters, toothless, hoofed, flying (wing), primates (large brain)
What is evolution?
A physical change as time goes by. It can be positive or negative.
What is an adaptation?
It is a beneficial change. They can be a behavioral change or physical change.
What is the sequence of vertebrate animal evolution?
Chordates ⇒Fish ⇒ Amphibian ⇒ Reptiles ⇒ Dinosaurs ⇒ Birds. Reptiles ⇒ Mammals ⇒ Homosapiens ⇒ Terminators and Ai
Notochord ⇒Vertebral column ⇒ Backbone
Nerve Cord ⇒ Spinal cord ⇒ Backbone
What is the heart evolution within the vertebrate?
Fish have a 2 chamber heart ⇒ Amphibian ⇒ a tadpole has a 2 chamber the adult has a 3 chamber heart ⇒ a reptile has a 3 chamber heart an alligator has a 4 chamber heart ⇒ Mammals and birds have a 4 chambered heart
What is animal behavior?
Animal behavior is the response to stimulus. (it is a signal which they get from the environment)
What is a stimulus?
A stimulus is a signal that causes an organism to react in some way.
What is a response?
It is an organism’s reaction to a stimulus. (All animal behaviors are caused by stimuli)
What does innate mean?
It comes from your DNA or the way you have been programmed.
What is an instinct?
It is a behavior without being taught (not
learned); a response that is inborn (coded in
the genes) and performed correctly the first
time.
What is learned behavior?
It is the change in behavior based on practice or experience.
What are the 4 types of learned behavior?
The 4 types of learned behavior are imprinting, conditioning, Trial - and - Error Learning, and insight are the 4 types of learned behavior.
What is imprinting?
A newborn who recognizes and follows the first moving object they see (e.g., duckling follows human)
What is conditioning?
A specific stimulus or response leads to a good or a bad outcome (e.g., Pavlov’s dog, salivate at the sound of a bell).
What is Trial - and - Error Learning?
Repeated practice that results in a reward and avoids behaviors that result in a punishment.
What is insight learning?
Using what you know to solve a problem.
What are the 8 types of behavior?
Communication, pheromone, aggression, courtship behavior, group behavior, circadian rhythm, hibernation, and migration are the 8 types of behavior.
What is communication?
Animals use sounds, scents, body movements to communicate.
What are pheromone?
It is a chemical released by one animal that affects the behavior of another animal of the same species (e.g., ant pheromone trail).
What is aggression?
It is a threatening behavior that one animal uses to gain control over another animal. Aggression is due to competition over limited resources (food, water, space, shelter, and mates).
What is courtship behavior?
Behavior to prepare for mating.
What is group behavior?
It is beneficial for the safety in numbers and sharing (cooperation) in work, food, water, and shelter.
What does circadian rhythm do?
Behavior cycles that occur over a day (e.g., awake/work daylight, and sleep at nighttime.
What is hibernation?
They sleep/reduced activity during winter in which the need for food has stopped.
What is migration?
A routine, seasonal journey of an animal from one place to another and back again.
What is body organization?
Cell→ Tissue →Organ→ Organ System
Simple to complex
What is a cell?
The basic unit of an organism (life)
What is a tissue?
A group of same cells that have the same function (activity; do the same thing)
What are the types of tissues?
Muscle, nervous, connective, epithelial (= covering; skin and organ lining)
What is an organ?
It contains different tissues but performs a specific function (activity); Example: heart – pumps blood; stomach – store food; begins breakdown solid food.
What is an organ system?
A group of different organs working together to perform a major (complex) function.
What are the types of human organ systems?
Skeletal, Muscular, Digestive, Circulatory (see below), Lymphatic, Respiratory, Excretory, Nervous, Endocrine, Reproductive, Immune Example: Circulatory System – transports materials to (nutrients) and from (waste) body cells.
What is dynamic equilibrium?
It is a state of balance in nonliving, physical systems.
What is homeostasis (Regulation)?
It is the process by which an organism’s internal environment is kept stable in spite of change in the external environment [a state of balance/stability in living, biological systems].
What is the vertebral column?
A backbone
What is a vertebrae?
Disc-like small bones separated by cartilage (protection, flexibility, movement).
What are joints?
Where two bones come together; allows bones to move in different ways
What are immovable joints?
There is no movement; ex: skull bones
What are movable joints?
There is movement.
What are ligaments?
A tissue holding joints together; bone to bone.
What is cartilage?
It is a cushion.
What are the three types of joints?
Hinge joints, ball and socket joint, pivot joint, and gliding joint.
What is a hinge joint?
Moving forward/backward; ex: knee, elbow
What is a ball and socket joint?
Free movement; ex: shoulder, hip
What is a pivot joint?
Side to side rotation; ex: neck
What is a gliding joint?
A sliding motion; ex: wrist,ankle
What is an immovable muscles?
Not under conscious control; example: heart beat, breathing, digesting food.
What is a movable muscles?
Under conscious control; example: facial expressions, walking.
What does striated mean?
Muscles with lines
What does non-striated mean?
Muscles without lines
What is a skeletal muscle?
Attached to and moves bones of the skeleton striated muscle, voluntary muscle quick, fast but tires quickly.
What is a tendon?
An attached muscle to bone.
What is a cardiac muscle?
Heart only striated, branching muscle involuntary muscle does not tire.
What is a smooth muscle?
Part of internal organs and blood vessels. Not striated involuntary muscle moves slowly, tires more slowly.
Why do muscles work in pairs?
Muscles work in pairs because muscle cells can only contract (they cannot extend or expand). One muscle contracts, the other muscle relaxes.
What is skin?
Covers and protects from injury, infection, water loss, Regulates body temperature, Removes waste (perspiration), Collects environmental information, Produces Vitamin D. It is also the largest organ in the human body. The skin consists of epidermis and dermis.
What is the Epidermis (Outer Layer)?
No nerves, no blood vessels.
What is the Upper Epidermis (Dead cell layer)?
It consists of dead cells which shed after two weeks
What is the Lower Epidermis (Skin producing factory)?
It consists of living epidermal cells which divide forming new cells. After two weeks, they die, moving upward, becoming part of the Upper Epidermis surface layer.
What is the skin’s function?
It protects, cushions, carries away bacteria, produces melanin.
What is melanin?
Skin (color) pigment which protects against burning.
What is dermis?
It is located below the epidermis and above the fat layer ** contains the nerves, blood vessels, sweat and oil glands, hair follicle.
What are sweat glands?
Produce perspiration (temperature regulation).
What are oil glands?
It is waterproof hair and keeps skin moist.
What is hair follicle?
The site of hair growth.
What is below dermis?
Fat Layer, Muscle, Bone
How to keep your skin healthy?
A diet keeps clean and dry and limits sun exposure. See dermatologists every year to check skin for precancerous growths.
What is skin cancer?
Over exposure to sunlight can damage skin cells where cells divide uncontrollably (basal cell carcinoma, squamous cell carcinoma, malignant melanoma). Too much Sun: skin leathery and wrinkled.
What is the digestive system?
Breakdown food into nutrient molecules and the absorption of nutrient molecules. Two (2) types of digestion.
What is absorption?
Nutrient molecules pass through the wall of the small intestine into the bloodstream (Circulatory System).
What is mechanical digestion?
Physical breakdown by chewing (mouth) and churning (stomach).
What is chemical digestion?
Chemicals (enzymes, acids) breakdown food. Example: enzymes in mouth breakdown starch into sugars, acids in stomach breakdown proteins.
What is the mouth?
Digestion begins; saliva contains water, DNA, enzymes (which breaks down starches). Teeth physically break down food.
What are the types of teeth?
Incisors, Canines, and Molars
What are incisors?
Cut into pieces
What are canines?
It tears, slash into pieces
What is a molar?
Crush and grind into powder.
What is an enzyme?
Protein that speeds up chemical reactions.
What is the esophagus?
Muscular tube connecting mouth to stomach.
What is the epiglottis?
Flap (sheet) of tissue which seals off trachea (windpipe) to lungs.
What is peristalsis?
It is an involuntary muscular contraction that pushes food toward the stomach and through intestines.
What is the stomach?
Holds/stores food; where protein breakdown begins: mostly mechanical digestion (churning) but some chemical digestion (acids, enzymes) occurs.
What is digestive juice?
It is an HCL acid and pepsin (enzyme).
What is pepsin?
An enzyme that breaks down protein.
What is HCL acid?
A chemical that breaks down solid food into paste (chyme); kills bacteria.
What is mucus?
It covers the stomach wall which protects the stomach against ulcers (= holes in stomach wall).
What is a Villi/microvilli?
It increases the surface area. An increased rate of absorption to feed trillions of body cells each day.
What is the purpose of the villi and microvilli?
It increases the surface area for rapid nutrient absorption.
What is the stomachs function?
It holds and stores food; protein (breakdown) digestion begins.
What is the small intestine’s function?
The most chemical digestion and absorption (into Circulatory System) occurs; enzymes enter the small intestine from the small intestine wall, liver and pancreas. Wall covered by finger-like villi which absorb nutrient molecules. Villi increases surface area which increases the rate of absorption. (feeding of body cells) Nutrient molecules move by osmosis from the small intestine into capillaries (Circulatory System).
What is the liver?
It breaks down medicine and alcohol (poisons, toxins) removes nitrogen and produces bile.
What is the bile?
It is stored in gallbladder (below the liver); like a “dish detergent” . . . physically breaks down large fat particles into small fat particles.
What is the pancreas function?
It produces enzymes which enter the small intestine and chemically breaks down fats, proteins and complex carbohydrates (starch).
What is the large intestines functions?
It contains good bacteria that produces Vitamin K (clots blood) → removes water from undigested food which enters the bloodstream by absorption.
What is the rectum?
It stores undigested solid waste.
What is the anus?
A muscular opening at the end of rectum.
What is food?
It provides the materials for energy, growth and repair of tissues.
What is a calorie?
The amount of energy needed to raise the temperature of one gram of water by one degree is Celsius.
What is metabolism?
It represents the sum of all chemical reactions that take place within an organism.
What are nutrients?
They are substances in food that provide the raw materials and energy the body needs to carry out all vital processes. There are six (6) nutrients: carbohydrates, fats, proteins, vitamins, minerals and water.
How much water is the human body made up of?
Human Body - ~ 60-75% water
What are carbohydrates?
major source of quick energy; provides the raw materials to make parts of cells.
What is fat?
It is stored energy. Fats form part of the cell membrane and fatty tissue protects and supports your internal organs and insulates your body. Brain Development
What is a protein?
It is needed for tissue growth and repair/maintenance (ex: muscle).
What role do proteins play?
Proteins play a role in chemical reactions within the cell (= enzymes).
What are vitamins and minerals?
They are needed in small amounts to carry out chemical reactions.
What is water?
It is important because the chemical reactions take place in water; blood flows due to water; joints lubricated by water; body temperature is regulated by water (perspiration/sweat).
What is a simple carbohydrate?
Candy (refined white sugar), fruits (fructose), milk (lactose)
What are complex carbohydrates?
Breads, Rice, Pasta, Crackers
What is the circulatory (cardiovascular) system?
A tube (transport) system which carries nutrients to body cells and carries away waste. Blood moves through these tubes carrying nutrients and waste as well as contains cells that fight disease.
What is the heart?
It consists of four (4) chambers that pumps blood throughout the body.
What is the atria?
The upper chambers that receive blood.
What is a ventricle?
The lower chambers that pumps blood away from the heart.
What is the right ventricle?
It pumps blood to the lungs.
What is the left ventricle?
It pumps blood to body (aorta).
What is the pattern of blood flow?
First Loop (Right Ventricle) Heart Lungs
Second Loop (Left Ventricle; Aorta) Heart Body
What are valves (veins)?
It prevents back flow (due to lower blood pressure).
What is the pacemaker?
It sends out electrical signals to the heart; heart muscle contracts regularly.
What are the types of blood vessels?
Arteries, veins, and capillaries
What are arteries?
It carries blood away from heart.
What are veins?
It carries blood to heart; has valves
What are capillaries?
A tiny thread-like vessels for nutrient & waste exchange between blood and body cells.
How many cells does a human body consist of?
The human body consists of 50-75 trillion body cells that need to be fed and waste removed every day.
What is blood composition?
Plasma, red blood cells, white blood cells, platelets; produced by the red bone marrow.
What is plasma?
A liquid part; 90% water, 10% nutrients (glucose, fat, vitamins, minerals), waste: “CO2, water vapor”, proteins, chemical messengers.
What are red blood cells?
It carries oxygen to body cells; contains hemoglobin (iron protein); lifespan 4 months; if blood bright red oxygen present, if blood dark red/brown, no oxygen present.
What are white blood cells?
They are disease fighting cells; lifespan months-years; specialized cells.
What makes the alarm system?
T-cells and B-cells.
How does the alarm system work?
Cells produce chemicals (antibodies) to fight invasion. Cells attack the invaders.
What are platelets?
They clot blood; produces fibrin protein.
What is a blood type?
They are surface molecules found on red blood cells.
What is Rh factor?
They also are surface molecules found on red blood cells
Does Rh+ have an Rh factor or not?
If Rh +, have Rh factor.
Does Rh- have an Rh factor or not?
If RH -, doesn’t have an RH factor.
What happens if Rh- receives Rh+?
If Rh- receive RH+ blood, it leads to clumping of blood and death.
What are the four blood types?
A, B, AB, O
What are the three allele types?
A & B
What are the universal receivers?
AB
What is the universal donor?
O
What is transfusion?
The transfer of blood from one organism to another organism; if blood clumps, clogs capillaries, results in death.
What is the lymphatic (Filtering) system?
It cleans and returns fluid to the Circulatory System.
What is lymph?
It contains water, glucose, white blood cells.
What are lymph nodes?
It traps invaders microorganisms (bacteria); node – “filter”
How many cells does the body have?
The human body consists of 30-60 trillion body cells.
What is the respiratory system?
It moves oxygen from the atmosphere to body cells; removes gaseous waste (CO2 & water vapor)
What is respiration?
It is the chemical reaction: Sugar + oxygen → energy + CO2 + water vapor
What is breathing?
It is the movement of air into and out of the lungs.
What is a nose?
It is where the air enters through nostrils.
What is the pharynx?
Throat; shared with digestive system.
What is the larynx?
A voice box; vocal cords.
What is the trachea?
A windpipe; tube from pharynx to bronchi (lung).
What is the epiglottis?
Trachea (windpipe) flap during swallowing of food & liquid.
What is bronchi?
A tube branches within lungs.
What are the lungs?
An organ that transfers gasses from the environment (atmosphere) into or out of the Circulatory System.
What is an alveoli?
A grape-like structure at the end of bronchi-oles surrounded by capillaries.
What is the excretory system?
It collects and removes waste:
solids - rectum of Digestive System
liquids - kidneys of Urinary System
gasses - lungs of Respiratory System.
What is urology?
It is the study of the urine and the genitourinary tract in health and disease.
What is proctology?
It is the branch of medicine concerned with the anus and rectum.
What do you study in urology and proctology?
Studies kidney problems (kidney stones, gout)
Studies urinary bladder problems (bladder stones)
Studies prostate problems (difficulty urinating; inflammation & cancer)
Studies rectum / anus problems (hemorrhoids)
What are excretory organs?
They are kidneys, lungs, skin ureter, urinary bladder, urethra
What is a kidney?
It is an organ which removes liquid waste from the blood; a “filter”; humans have 2 kidneys. It contains many nephrons; Each nephron filters the blood. By the process of osmosis (diffusion), urea and some water is removed but sugar and much of the water is returned to the blood (reabsorption). The urine is then stored in the urinary bladder for future removal from the body.
What is urea?
The breakdown of protein (yellow color).
What is liquid waste?
It is urine (urea, water, other).
What is the ureter?
It is a tube which connects from kidneys to urinary bladder.
What is the urinary bladder?
A sac-like muscular organ which stores urine.
What is the urethra?
A tube which connects the urinary bladder to the outside of the body.
What are nephrons?
A filter liquid toxins removed (Urine) water reabsorbed/saved.
How many nephrons does each kidney have?
Each kidney = 1 million nephrons
What does it mean to urate?
They are salts of Uric acid.
What does gout mean?
Too high Uric acid levels in blood serum
What is the immune system?
An infectious disease, pathogen, toxin, antibody, antigen, phagocyte, lymphocyte, T Cells, B cells, immune response, fever, inflammatory response.
What are pathogens?
They are organisms that cause disease.
What is an infectious disease?
It is a disease caused by a foreign microorganism within the body.
What are the four types of pathogens?
Bacteria, virus, fungi, and protists.
How are pathogens spread?
They can be spread by an infected person, soil, food, water, a contaminated object, and an infected animal.
What is skin?
A dead skin cell flakes off removing pathogens from the body; outer epidermis acts as a barrier too; rapid scabbing prevents pathogen entry into the body.
What are the breathing passages?
The nose, mouth, throat contains mucus and cilia trapping and removing pathogens. Coughing/sneezing also removes pathogens.
What do the mouth and stomach have?
The mouth has saliva and the stomach has acid that can kill pathogens.
What are white blood cells?
They are disease fighting cells. There are many different types of WBC’s, each having its own particular function. Phagocytes (WBC) eat pathogens, destroying them.
What is inflammation?
Increased blood flow (enlarges blood vessels) bringing more WBC’s to affected areas (red, swollen, warmer).
What is fever?
Increasing body temperature fights infection; pathogens do not grow/reproduce well at higher temperatures.
What are antigens?
A unique surface marker molecule on pathogens.
What are antibodies?
A molecular tag that attaches to antigen to recognize as foreign.
What are lymphocytes?
WBC’s that can distinguish between different kinds of pathogens.
What are the two types of specialized cells?
The two types of specialized cells are T-cells (Alarm, Attack) and B-cells (Antibody “Tag” Factory)
What are T-cells (Alarm, Attack)?
Specialized cells that recognize each kind of pathogen. T-cells multiply, then some attack pathogens (“killer T-cells”) while others activate B – cells.
What are B-cells (Antibody “Tag” Factory)?
Specialized cells that produce specialized antibodies (proteins) that tag the pathogen for destruction. The antibody binds to the antigen on the pathogen, marking it for destruction by the phagocytes.
What is the nervous system?
Stimulus, response, neuron, nerve impulse, dendrites, axon, nerve fiber, nerve, sensory neuron, interneuron, motor neuron, synapse, reflex arc. It receives and responds to information obtained both inside and outside of the body; also helps to maintain homeostasis.
What is a stimulus?
An environmental signal that an organism reacts to.
What is a response?
What the body does in reaction to a stimulus.
What is neuron (nerve cells) ?
A specialized cell that carries information; building block of Nervous System.
What is nerve impulse?
A message/information being carried. It begins in a nerve cell’s dendrite, travels down axon to axon tip where it crosses over to the next nerve cell at the synapse.
What is a neuron?
It consists of nucleus, axon and dendrites.
What are dendrites?
It carries impulses toward the cell body.
What is an axon?
It carries impulses away from the cell body.
What are nerve fibers?
They are axons & dendrites.
What are nerves?
A bundle of nerve fibers.
What are the three kinds or neurons?
Sensory Neuron, Interneuron, and Motor Neuron
What is a sensory neuron?
It picks up stimuli and converts it into an impulse.
What is an interneuron?
It carries impulse from one neuron to another neuron (within the brain or spinal cord).
What is a motor neuron?
It brings impulse to muscle or gland which then reacts in response.
What is a synapse?
It is the gap between the axon tip and the neighboring dendrite. Chemicals (dopamine, serotonin) carry the impulse across the synaptic gap.
What is the central nervous system (CNS)?
The “control center”of the body; consists of the brain and spinal cord.
What is the brain?
It controls most functions of the body.
What is the spinal cord?
It links the brain to the Peripheral Nervous System.
What is the cerebrum?
It processes sensory information, mental processes (thought: learning, remembering, judgment; consciousness); largest part of brain.
What does the left half of the brain do?
Math, Science (analytical)
What does the right half of the brain do?
Music, Art, (creativity)
What is the cerebellum?
Muscle coordination & balance.
What is the brain stem?
A primitive/basic involuntary activities (breathing, heartbeat, blinking eyes)
What is the Peripheral Nervous System (PNS)?
It consists of all nerves outside of the Central Nervous System. Subdivided into the Somatic & Autonomic Nervous System.
What is the Somatic Nervous System?
It controls voluntary actions (ex: taking notes, writing).
What is the Autonomic Nervous System?
It controls involuntary actions; reflex actions (ex: blinking, breathing)
What is the reflex action?
The autonomic response that occurs very rapidly and without conscious control; helps to protect the body; muscle and spinal cord involvement but not the brain (see transparency).
What is the nervous system damage?
Concussion, Stroke and Spinal Cord injuries.
What is a concussion?
A bruising of the brain when brain collides against the skull (e.g., car accidents, football, boxing).
What is a stroke?
The bleeding of the brain.
What is a spinal cord injury?
Cut or crushed, resulting in paralysis (loss of movement) or death.
What is the endocrine system?
Hormones, Hypothalamus, pituitary, thyroid, parathyroid, thymus, adrenal gland, adrenaline, negative feedback loop, gigantism, dwarfism.
It produces hormones which control/regulate organ & tissue activities; regulate growth & development.
What is Hypothalamus (middle brain)?
It is linked to the nervous system which maintains homeostasis & control of the pituitary gland.
What is a pituitary gland?
Growth, blood pressure,water balance regulates; signals thyroid gland to produce hormones.
What is a thyroid gland?
It produces hormones; controls energy inside the cell.
What is a parathyroid?
It regulates blood calcium.
What is the thymus
It helps the immune system’s development.
What is the pancreas?
It controls blood sugar.
What is the adrenal (above kidneys)?
It triggers adrenaline during emergency situations; “fight or flight response”.
What is the endocrine system?
It uses a negative feedback loop (like a home thermostat) to maintain homeostasis. Through negative feedback, when the amount of a specific hormone in the blood reaches (rises) to a certain level, the hypothalamus sends a signal to stop the release of that hormone (homeostasis). If the hormone level drops, a signal is sent to the hypothalamus to release the hormone.
What is the male reproductive system?
It produces sperm and hormone testosterone; consists of testes, scrotum, penis.
What are testes?
It is an organ that produces sperm and testosterone (which controls male physical characteristics). It also regulates sperm development; male sexual development (testosterone).
What is the scrotum?
An external pouch containing testes.
What is the semen?
A mixture of sperm cells and fluids.
What is the penis?
A male sex organ; contains the end of urethra where urine/semen leave the body.
What is the female reproductive system?
It produces eggs and hormones estrogen, progesterone; consists of the ovaries, fallopian tubes, uterus, vagina.
What are ovaries?
They produce egg cells and estrogen (which controls some female characteristics) and progesterone. It triggers egg development (estrogen); female sexual development (progesterone).
What is the fallopian tube?
It connects the ovary (egg) to the uterus; where fertilization occurs. Each month, one of the ovaries releases an egg.
What is the uterus (womb)?
A hollow muscular organ; the zygote develops (embryo,fetus,newborn) in the uterus.
What is the vagina?
An opening between uterus and outside body.
What is sexual reproduction known as?
It is also known as meiosis.
What are gametes?
The egg which is the female sex cell and the sperm which is the male sex cell which then form a zygote.
What is an egg?
A female sex cell which has 23 chromosomes.
What is a sperm?
A male sex cell which contains 23 chromosomes.
What is fertilization?
The joining of sperm and egg.
What is a zygote?
A fertilized egg which contains 46 chromosomes.
What is mitosis?
When a zygote undergoes cell division :
zygote → embryo → fetus → newborn (birth).
What is a chromosone?
An X-shaped structure in the cell’s nucleus contains units called genes which carry genetic information (inherited traits).
What is the menstrual cycle?
A monthly cycle of change consisting of egg development in ovary and uterus prepares for the arrival of the embryo.
What is the midway of an egg?
An egg released from the ovary into the fallopian tube (= ovulation); where fertilization occurs. If there is no fertilization, menstruation (“period”) occurs.
What is the beginning of an egg?
The development of a mature egg; uterus thickens.
What is menstruation?
Blood, unfertilized egg, uterus tissue lining leaves the body through vagina.
What is fertilization?
The joining of sperm and egg forming zygote.
What is a zygote (one-cell stage).
A fertilized egg
What is the pre birth development?
Zygote → Embryo → Fetus → (birth) → newborn baby
What is the embryo?
From “two cell stage” to 8 weeks; cell division occurs.
What is the fetus?
3-9 months (birth)
What is the amnioctic sac?
A fluid filled sac that cushions/ protects embryo/fetus.
What is the placenta?
Regulating organs between baby & mother; nutrients/oxygen in & waste out.
What is the umbilical cord?
It connects the fetus to the placenta (belly button) (see transparency).
What is birth?
9 months in humans; three stages: labor, delivery, afterbirth.
What is labor?
A strong muscular contraction of uterus, cervix (opening) enlarges.
What is delivery?
From the uterus to the outside world.
What is afterbirth?
Contractions push placenta and other membranes/fluid out through the vagina.
What are identical twins?
From a single fertilized egg that splits results in two genetically identical individuals (copies).
What are fraternal twins?
Two different eggs released & fertilized by two different sperm; two different individuals sharing the same womb.
What is infancy (1-2 yrs)?
A dramatic change in shape & size; nervous / muscular system development; learning new physical skills.
What is childhood (2-12 yrs)?
A more active, independent, further physical & mental changes
What is adolescence (13-19 yrs)?
A gradual change from child to adult.
What is puberty (9-15 yrs)?
At 12-14 yrs, ability to reproduce; produce baby.
What is a young adult?
20 to 50yrs
What is a senior adult?
60+ yrs; wisdom, knowledge about life.
What is aging?
(30+ yrs) skin begins to wrinkle, decrease muscle strength, changing hair color, eye problems (40-65 yrs) menopause (ovulation, menstruation stops), decrease sperm.
What is slow aging?
Diet and excercise.
What is a nucleus?
A membrane bound control center of a cell containing X-shaped structures called chromosomes. Each chromosome consists of two chromatids held together by a centromere.
What is a chromosome?
An X-shaped structure consisting of a single DNA molecule.
What is a DNA molecule?
Consisting of genes, the “code of life”
What is an organism?
An organism contains ½ genes mom + ½ genes dad
What is interphase?
Chromosomes can not be seen; doubling of chromosomes; nuclear membrane present; 99% of cell life.
What is prophase?
A spindle fibers form; chromosomes seen (randomly arranged).
What is metaphase?
Chromosomes line up in the Middle, no nuclear membrane.
What is anaphase?
Chromosomes move Apart (Away)
What is telophase?
Two joined cells; two nuclear membranes form.
What is cytokinesis?
Two separated daughter cells form.
What is cell division?
The growth (embryo, fetus, infancy → adulthood) and repair/maintenance of an organism.
What is asexual reproduction?
Some examples are (ex: bacteria, hydra, worms) - simple life :
A parent / 2 daughter cells parent/daughter cells identical appearance (genes)
A parent / daughter cell has the same number of chromosomes.
What is sexual reproduction?
Two parents a male and a female daughter cells are a mixture/combination of genes compared to parent cell (by crossover) parent to daughter cell different number of chromosomes.
What is the difference between parent chromosomes and daughters chromosomes?
Parent 2x chromosomes compared to daughter cells.
Daughter half (½) chromosomes compared to the parent cell.
What is an organism (offspring)?
½ alleles mom; ½ alleles dad.
What is cancer?
An abnormal cell division; uncontrolled mitosis; certain DNA mutations cause cells to divide in an uncontrolled way.
How are mutations caused?
Mutations are caused by
1] Chemicals (carcinogens; ex: smoking, gasoline, alcohol, fried foods).
2] Radiation (high dose; atomic bomb, nuclear reactor meltdown Chernobyl (for Simon), Ukraine)
3] Hereditary (ex: breast cancer)
What is the treatment?
Surgery, radiation, drugs, immunotherapy.
How can you prevent it?
To avoid smoking, eat a healthy diet, and protect skin from bright sunlight. Vitamins may help.
What is a gene?
Allele (dad) + allele (mom)
What are alleles (part of the gene)?
T or t
What is a purebred (homozygous)?
The same alleles (gene); TT, tt
What are hybrids (heterozygous)?
A mixture of alleles; Tt
What is being dominant mean?
It shows itself (strong); Tt, TT
What does recessive mean?
It is often hidden (weak); tt
What is an offspring?
A child
What is a punnet square?
It is a technique used to predict what percentage of offspring (children) will be likely to have a particular trait (physical feature).
What is a trait?
A physical (behavioral) feature of organism.
What is a genotype?
The genetic makeup of an organism. Ex: TT, Tt, tt
What is a phenotype?
The physical observable appearance of an organism. Ex: tall, short
What is an organism?
½ alleles/genes mom; ½ alleles/genes dad
What are we made up of?
Mixture of our parents (our dominant traits are usually shown; only if both parents have recessive alleles will trait be shown)
What is sexual reproduction?
It produces variety (variation) allows the organism to be better adapted to a changing environment and thus a greater survival advantage.
What is a carrier?
A person who does not show the observable trait but is carrying the hidden recessive allele on the sex chromosome.
What are sex-linked genes?
Genes carried on sex chromosomes; example red-green colorblindness
What is cystic fibrosis?
Mucus in lungs & intestines; mutation (deletion) of 3 base pairs.
What is sickle-cell anemia?
A sickle shaped red blood cell which cannot carry much oxygen; codominant allele.
What is hemophilia?
Slow or no blood clotting; recessive allele (sex-linked disorder).
What is down syndrome?
Extra copy of chromosome 21 causing a form of mental retardation;
What is normal 21?
II-shaped (2 chromatids)
What is down syndrome 21?
III-shaped (3 chromatids)
What is a karyotype?
A picture of all chromosomes from within a (body) cell.
How many chromosomes does a human have?
46 human chromosomes or 23 pair of chromosomes 23rd pair is X (the sex chromosome)
What is selective breeding?
To select or choose organisms with desired traits (features).
What is inbreeding?
Mating (crossing) similar individuals having similar features.
What is an example of inbreeding?
Mother (sister) X Father (brother) = King Tut to maintain the “royal bloodline”
What is hybridization?
Mating different individuals to produce offspring with the desired traits.
What is an example of hybridization?
Corn (many kernels) X Corn (disease resistant) = Corn (many kernels + disease resistant)
What is the purpose of genetic engineering?
To produce new medicines, improve food crops, superplants, super animals, superhumans? (future mankind?).
What is genetic engineering?
Genes from one organism are transferred into the DNA of another organism [human (gene) to bacteria].
What are some examples of genetic engineering?
- Bacteria plasmid (DNA ring) used to produce insulin for diabetics.
- Bacteria plasmid (DNA ring) used to produce human growth hormone to help the development of very short people.
- A firefly’s bioluminescence gene transferred into a cat’s egg can produce a cat that glows in the dark.
What is cloning?
Donor DNA transferred to empty egg; offspring grows up looking exactly like donor; donor/offspring physically identical. Cloning is an asexual (mitotic) process occurring in sexually reproducing organisms.
What is a clone?
Donor = genetically identical Child
Parent = Child < or > Child = Child
What are identical twins?
Child A = Child B genetically identical.
What is a specie?
They are individuals that mate and produce fertile (can bear children) offspring.
What is a variation?
They are differences between individuals of the same species.
What is an adaptation?
A trait (feature) that helps an individual survive and reproduce; very helpful variation.
What is natural selection?
The process by which individuals that are better adapted to the changing environment (nature) are more likely to survive and reproduce than other individuals of the same species (extinct).
What is extinction?
Species (individuals) no longer exist.
What is a fossil?
A fossil is the preserved remains, or traces of remains, of ancient organisms
What is evolution?
A change (in physical shape) over time
What is lineage?
Line of descent
What is motion?
If your distance from another object (place) is changing.
What is a reference point?
It is a place or object used for comparison to determine if something is in motion. An object is in motion if it changes position relative to a reference point.
What is a meter, centimeter, millimeter, kilometer, and what is speed?
Meter (m) = unit of length
Centimeter (cm) = 1/100 meter
Millimeter (mm) = 1/1000 meter
Kilometer (km) = 1000 meters
Speed = distance (m) (km) (cm)
time (s) (hr) (s)
What is average speed?
When moving objects are not constant (changing speed).
How do you calculate average speed?
Average Speed = total distance
total time
What is acceleration?
A rate at which velocity changes (increasing speed, decreasing speed or changing direction)
What is an example of acceleration?
A pitcher throws a ball, bat hits a ball, car passes another car, biking down hill.
What is declaration?
Object’s slowing down; also called “negative acceleration”
What is an example of declaration?
Catching a softball, the car stops at a light, boat stops pulling water skiers.
What is circular motion?
A ferris wheel accelerate.
What are the units of acceleration?
m/s2, km/h2
What does a curved line mean?
curved line = acceleration
What does an upward curved line mean?
upward curved line = increasing speed
What does a downward curved line mean?
downward curved line = decreasing speed
What does the slope of a line mean?
slope of the line = speed
What is force?
A push or pull; described by strength (N) and direction
What is the unit of force?
Newton (N); where 1N = 100 g
What is the force instrument?
force meter/spring scale (N)
What is net force?
Combining forces if forces are in the same direction, you add them together to produce a net force.
What is an unbalanced force?
Occur when a net force is present causing a change in the object’s motion.
If two unbalanced forces are in the same direction, the net force is the sum (+) of the forces. If two unbalanced forces are in the opposite directions, the net force is the difference (-) between the forces.
What is a balanced force?
Occur when equal (strength) forces are acting in opposite directions. The net force is zero. Balanced forces do not change the object’s motion.
What is efficiency?
Efficiency of a machine compares the output work to the input work. Maximum efficiency is 100% but all machines have an efficiency of less than 100% because some work is wasted due to friction (heat loss).
What is the formula for efficiency?
Efficiency = Output Work x 100%
Input
What is friction?
The force that two surfaces exert on each other when they rub against each other.
What factors affect friction?
1) weight
2) rough versus smooth surfaces
3) lubricants (oils, grease); ball bearings
4) surface area
What are some examples of friction?
Press (rub) forcefully ~ high friction
Rough surface ~ high friction
Press (rub) slightly ~ low friction
Smooth surface ~ low friction
What is static friction?
Friction that acts on objects that are not moving. Static greater than sliding, rolling, fluid friction.
What is sliding friction?
Friction when two surfaces slide over each other.
What is rolling friction?
Friction when an object rolls across a surface. To reduce friction, use wheels or ball bearings.
What is fluid friction?
Friction when an object moves through a fluid. To reduce friction, use oils & lubricants; streamline.
What is gravity?
An attractive force between objects containing mass.
What is mass?
The amount of matter (atoms) in an object.
What is terminal velocity?
Maximum velocity of a free falling object occurs when the force of air resistance equals the weight of the object. Terminal velocity represents balanced forces where upward air resistance equals downward gravity.
What is distance?
The length between two points
increase mass ~ increase gravity
increase distance ~ decrease gravity
What is a free fall?
Only gravity acting on a falling object. Objects accelerate as they free fall because gravity is an unbalanced force. In a vacuum, all objects in free fall accelerate at the same rate regardless of their masses. Gravitational acceleration near Earth is 9.8 m/s2.
What is air resistance?
It is a type of fluid friction as an object falls through the air. Greater surface area of object ~ increase in air resistance ~ slower the object falls. Air resistance increases as velocity increases.
What is projectile motion?
It is an object that is thrown. A projectile (with horizontal motion) will fall at the same rate as any dropped object.
What is Newton’s First Law of Motion?
An object at rest will remain at rest and an object moving at a constant velocity will continue moving at a constant velocity, unless it is acted upon by an unbalanced force. Gravity and friction are unbalanced forces.
What factors affect inertia?
mass greater mass ~ greater inertia ~ greater force to change motion
What is momentum?
A measure (quantity) of motion, where: momentum = mass x velocity (ρ = m·v) kg·m/s kg m/s more momentum ~ harder to stop
What is Newton’s third law of action?
For every action there is an equal but opposite reaction.
What is interia?
It is the tendency of an object to resist a change in motion. Example: when a car stops, inertia keeps you moving forward.
What is Newton’s second law of motion?
Acceleration depends on the object’s mass and the force acting on the object.
What is an example of momentum?
ball (low mass) ~ less momentum car (high mass) ~ more momentum moving arrow (high velocity) ~ more momentum.
What is the Law of Conversation and momentum?
States that in the absence of outside forces, the total momentum of objects that interact does not change. The amount of momentum is the same before and after they interact.
What happens when collisions happen with two moving objects?
Total momentum is conserved. The momentum of one train car decreases while the momentum of the other car increases.
What happens when collisions happen with one moving object?
Total momentum is conserved. All of the momentum has been transferred from the moving car to the initially stationary car.
What happens when collisions happen with connected objects?
Since the mass is doubled and the velocity is divided in half, the total momentum remains the same.
What is work?
Work occurs when you exert a force on an object that causes the object to move some distance. In addition, the object must move in the same direction in which the force is exerted.
What is the formula for work?
Work(J) = Force (N) X Distance (m)
How is work done on an object?
Work is done on an object when:
1] An object moves a distance.
2] Force is exerted on the object, and
3] The force and motion direction are parallel (same). Carrying an object = no work
What is power?
At the rate at which work is done.
What is the formula for power?
J/s or Watt (W), where 1W = 1J/s
What is a machine?
A device that allows you to do work (Wi) easier or more effectively. A machine changes the way in which work is done.
How does a machine make work easier?
A machine makes work easier by changing at least one of three factors:
1] the amount of force you exert (input force, Fi)
2] the distance over which you exert your force (input distance, Di)
3] the direction in which you exert your force (input direction).
What is a simple machine?
A simple machine is a mechanical device that changes the direction or magnitude of a force.
What are the six basic kinds of simple machines?
There are six basic kinds of simple machines - inclined plane, wedge, screw, lever, wheel & axle, and pulley.
What is an inclined plane?
A flat sloped surface
What is a screw?
An inclined plane wrapped around a cylinder.
What is a wedge?
Two inclined planes (back to back) that can move; produces two output forces (FO).
What is a lever?
A rigid bar that pivots/rotates on a fixed point.
What is a first class lever?
Change force direction; as the fulcrum close to Fo , Fo increases.
What are some examples of a first class lever?
Scissors, pliers, seesaw
What is a second class lever?
Same force direction; as the fulcrum close to Fo , Fo increases.
What are some examples of a second class lever?
Doors, nutcracker, bottle opener
What is a third class lever?
Same force direction; as fulcrum close to Fi , Fo decreases.
What are some examples of third class levers?
Fishing pole, shovel, baseball bat
What is a fulcrum?
A fixed point that a lever pivots around.
What is a wheel and axle?
A two circular/cylindrical objects that are connected together and rotate around a common axis, where: the wheel has a larger radius object and the axle has a smaller radius object.
What are some examples of a wheel and axle?
Screwdriver, door knob, steering wheel
What is a pulley?
A grooved wheel with a rope (cable) wrapped around it.
What are the three types of pulleys?
Fixed pulley, movable pulley, block and tackle pulley
What is a fixed pulley?
A pulley attached to a structure (ceiling, wall). Fi = Fo , change in direction; MA = 1
What is a movable pulley?
A pulley attached to a moving object. increase Fo , no change direction; MA = 2
What is a block and tackle pulley?
A fixed & movable pulley system. increase Fo , no change direction; MA = varies
What is a compound machine?
A combination of two or more simple machines.
What is a mechanical advantage?
The number of times a machine increases the input force (Fi).
What is efficiency?
Compares output work to input work.
What is an ideal machines efficiency?
100%. A real machines efficiency is less than 100% because some output work (Wo) is lost due to friction (heat loss)
What is energy?
The ability to do work
What is chemical energy?
From chemical bonds
What is electrical energy?
From moving electrons
What is mechanical energy?
From moving things (parts)
What is heat energy?
From moving molecules
What is nuclear energy?
From atom’s nucleus
What is light energy?
From moving photons
What is sound energy?
From vibrating objects
What is potential energy?
Stored energy; energy of position PE = weight x height
What is kinetic energy?
Motion energy KE= 0.5 mass x velocity²
What is the Law of Conservation of Energy?
“ Energy cannot be created or destroyed but can only change form ”
What are renewable resources?
They are materials that can be replaced at the rate at which we use them.
What are some examples of renewable resources?
Water, sunlight, trees, Food: livestock, produce
What are nonrenewable resources?
They are materials that cannot be replaced at the rate at which we use them.
What are some examples of nonrenewable resources?
Fossil fuels (petroleum [gasoline], coal, oil, natural gas, propane), minerals, metal ores (copper, gold, silver), soil
