Praxis Science Flashcards

Question

What is the correct order of biological organization of the following (from largest to smallest): Communities, population, biosphere, eyosystem. Define each one.

Answer 1

Biosphere: All of Earth and its atmosphere. Ecosystem: All of the rainforests on Earth. Community: All communities of primates within the rainforest. Population: All members of the community whose species is the golden tamarin.

Answer 2

made up of cells - at least one cell must exist for it to be living movement - it must move around use energy and get energy from a source - it must be able to get energy, convert it to a usable form, and use it grow and develop - it must change in characteristics and get bigger reproduction - it must make copies of itself one way or another response to stimuli - it must react to the environment at some point homeostasis - it must seek to maintain a stable internal environment

Answer 3

This rate at which velocity changes is defined as acceleration. An object that changes direction or speed is accelerating. The change in speed can be increasing or decreasing to be considered acceleration. For example, a car that maintains a speed of 25mph but changes direction is considered accelerating. A car that maintains due north but either increases or decreases speed is considered accelerating.

Answer 4

Velocity is defined as the speed of an object in a given direction. Two examples of velocity include a car traveling at 25 mph north or a plane flying at 575 mph in the northeast direction. An object that changes speed or direction has a change in velocity.

Answer 5

Inertia is the resistance of an object to a change in motion. For example, an elephant and rabbit are running at the same speed. The elephant will have greater inertia than the rabbit because the force needed to change the motion of the elephant will be greater than the force needed to change the motion of the rabbit.

Answer 6

Simple harmonic motion is a repetitive, or periodic, motion where the restoring force is proportional to the displacement from an equilibrium position. It includes things like pendulums and masses bobbing up and down on a spring. As you stretch the spring, there is a restoring force that wants to pull it back to where it began, and that force gets stronger the more you pull.

Answer 7

Projectile motion is motion that involves two dimensions, such as that which occurs in a water fountain. When you release a projectile, like a cannonball, a bullet from a gun, or a baseball coming off a bat, it moves in an up-and-down dimension and a forwards-and-back dimension.

Answer 8

Super Hot Gas: Plasma is a super hot gas where atoms are split into free-moving electrons and ions. Glows: Plasma often glows with bright colors, like in neon signs and lightning. Electricity: Plasma can conduct electricity, which means it can carry electric currents. Magnetic: It can be moved and shaped by magnets. Space Stuff: Plasma is found in stars, including the sun, and in space. High Energy: It has a lot of energy because of the high temperatures. Charged Particles: Plasma is made up of tiny charged particles that move around freely.

Answer 9

Circular motion is, unsurprisingly, motion in a circle. For example, imagine a ball being whirled above your head on a string or a satellite orbiting the Earth. When an object is moving in a perfect circle at a constant velocity, we have different equations we can use to describe the motion.

Answer 10

Unbalanced forces are forces on an object in opposite directions that are not equal. They cause an object to change velocity. Velocity is speed in a given direction.

Answer 11

Mass is defined as the quantity of matter in an object.

Answer 12

Net force is defined as the sum of all forces acting on an object.

Answer 13

A force is a quantity with magnitude and direction. Forces are often represented by arrows. This image shows the two forces acting on the object. The size of the force is represented by arrow length. The net force on this object is zero because the length of arrows is equal in both directions representing a balanced force. According to Newton's first law, this object will remain at rest until the net force is no longer balanced. An unbalanced force is a force applied in opposite directions that are not equal in size or magnitude.

Answer 14

Newtons (N)

Answer 15

Newton's second law states that the net force of an object is the product of its mass (m) and acceleration (a). This force equation relates: force mass x acceleration:

Answer 16

Linear motion is motion in a straight line. It's also called 1-D motion, because you're moving in one dimension. Linear motion is generally the easiest to describe: you just have one graph for displacement over time, one graph for velocity over time and one graph for acceleration over time. A car driving on a perfectly straight road is a good example of linear motion.

Answer 17

Velocity is how fast something is moving and in what direction, like a car going 30 miles per hour north. Acceleration is how quickly the speed or direction of that car changes, like when it speeds up or slows down.

Answer 18

Imagine you're pushing a toy car. When you push (apply force), the car starts to move faster (it accelerates). According to Newton's laws, the harder you push, the faster the car speeds up, changing how fast and in what direction the car is moving (its velocity). So, a force makes the car go faster or slower and changes its direction.

Answer 19

how close to being correct your data is

Answer 20

how close together your measurements are

Answer 21

an element

Answer 22

A molecule is comprised of two atoms/elements that are linked together chemically

Answer 23

A compound is a group of molecules. Compounds can be classified by the type of bond they share with other elements -- ionic or covalent.

Answer 24

1. Happens when an object moves from one point to another. 2. When the sum of all the external forces acting on the object = 0 (at rest or moving constant velocity or not experiencing any acceleration) 3. Sled traveling down a hill

Answer 25

1. Occurs when a rigid body revolves/orbits and axis. 2. when the sum of all the external torques acting on the object are equal zero (at rest or moving at constant angular velocity or not experiencing any acceleration) 2. Bike wheel spinning, ceiling fan turning

Answer 26

Work is the displacement (movement from one point to another) due to force (N) , depends on distance (m) object is moved Work (J) = force (N) x distance (m)

Answer 27

Since the object is not being moved, there is no work done.

Answer 28

joules (j), equal to newtons-meter (nm)

Answer 29

Displacement in physics is how far and in what direction an object has moved from its starting point.

Answer 30

A vector is a way to show both the direction and how far something moves or points.

Answer 31

Work = force x distance amount of force (N) the distance displaced (distance - m) the cause of the displacement

Answer 32

The power definition in physics is how much work is done in the time it takes to do it; work measures how much force is moved a certain distance. Thus power is how much force is moved a certain distance over time. Power (w) = work (j) / time interval (s)

Answer 33

Angular velocity is how fast something is spinning around a point or axis.

Answer 34

Watts (Remember work is measured in joules)

Answer 35

Energy is the ability to do work. It makes the things around us move or change.

Answer 36

The sun, known as radiant energy or solar radiation

Answer 37

Coal, natural gas, and oil End product of animal and plant remains stewing deep beneath the earths surface

Answer 38

A closed system is one where energy can be transferred within the system but cannot enter or leave the system itself.

Answer 39

Energy cannot be created or destroyed. It can: - Transfer from one obj to another (i.e., quarterback throwing a football) - Change from one form of energy to another (i.e., process food to fuel body)

Answer 40

Movement of waves (i.e., sound Movement of heat Movement of objects

Answer 41

moving matter and energy moving through a medium (the matter that waves travel through)

Answer 42

UV rays, microwaves, radiowaves

Answer 43

Thermal energy is the energy created by moving, vibrating atoms that make up matter (i.e., heat will flow from hotter object to cooler one - adding hot water to cold tub warms up water)

Answer 44

electrical nuclear (i.e. when atoms are split/combined) chemical (i.e. chem reactions inside batteries)

Answer 45

A photon is a tiny particle of light. It has no mass and travels at the speed of light, carrying energy. For example, the light from the sun is made up of countless photons that travel to Earth and make it bright.

Answer 46

When an atom absorbs a photon, the energy from the photon is transferred to the atom, causing one of its electrons to jump to a higher energy level or orbit. This makes the atom excited. For example, when sunlight hits your skin, atoms in your skin cells absorb photons, leading to changes that can cause a tan.

Answer 47

Acid rain is caused by pollutants like sulfur dioxide (SO₂) and nitrogen oxides (NOₓ) released into the atmosphere from burning fossil fuels in factories, cars, and power plants. These pollutants mix with water vapor in the air to form acids, which then fall to the ground as acid rain, harming plants, animals, and buildings.

Answer 48

Mitosis and meiosis are both processes of cell division, but they serve different purposes and have distinct differences: Mitosis: Purpose: To create two identical daughter cells for growth and repair. Number of Divisions: One division resulting in two cells. Chromosome Number: Daughter cells have the same number of chromosomes as the parent cell (diploid). Example: Skin cells dividing to heal a cut. Meiosis: Purpose: To produce sex cells (sperm and eggs) for reproduction. Number of Divisions: Two divisions resulting in four cells. Chromosome Number: Daughter cells have half the number of chromosomes as the parent cell (haploid). Example: Formation of eggs in the ovaries or sperm in the testes. In short, mitosis creates identical cells for body functions, while meiosis creates cells with half the genetic information for reproduction.

Answer 49

Nitrification is a process in which certain bacteria in the soil convert ammonia into nitrites and then into nitrates. This is important for plants because nitrates are a form of nitrogen that plants can easily absorb and use to grow. For example, when farmers add fertilizer to their fields, it often contains ammonia that gets turned into useful nitrates through nitrification.

Answer 50

A carbon sink is anything that removes more carbon from the atmosphere than it gives off. Three sources of carbon sink are the ocean, soil, and plants.

Answer 51

A scientist should use a scientific experiment to study a problem when they want to test a hypothesis and determine cause-and-effect relationships. This method allows them to control variables, collect data, and make observations under controlled conditions to see if their predictions hold true. For example, if a scientist wants to know if a new fertilizer helps plants grow faster, they would set up an experiment comparing plants with and without the fertilizer.

Answer 52

A scientist should use an observational study to study a problem when they want to gather data and identify patterns or correlations without interfering with the subjects or environment. This method is useful when it's not possible or ethical to manipulate variables. For example, studying the behavior of animals in the wild or observing the health effects of smoking in a population are situations where observational studies are appropriate.

Answer 53

Olivia’s quirky hamster eats all cookies.

Answer 54

John H. Ostrom was an influential American paleontologist best known for his groundbreaking work on the relationship between dinosaurs and birds. His impact on paleontology includes: - Dinosaur-Bird Connection: Ostrom's study of the dinosaur Deinonychus in the 1960s led to the revolutionary idea that some dinosaurs were more closely related to birds than to reptiles. This challenged the traditional view and provided evidence that birds are the modern descendants of theropod dinosaurs. - Feathered Dinosaurs: His work laid the foundation for the discovery of feathered dinosaurs, supporting the theory that feathers and other avian characteristics evolved in theropod dinosaurs before the appearance of modern birds. - Revising Dinosaur Biology: Ostrom's research contributed to a new understanding of dinosaur behavior and physiology, suggesting they were active, warm-blooded creatures rather than the sluggish, cold-blooded reptiles they were once thought to be. Ostrom's contributions significantly advanced our understanding of dinosaur evolution and bridged the gap between dinosaurs and birds, transforming the field of paleontology.

Answer 55

1. Evaporation: Water from oceans, rivers, lakes, and even plants turns into water vapor and rises into the air due to the heat from the sun. 2. Condensation: The water vapor cools down as it rises and turns back into liquid water droplets, forming clouds. 3. Precipitation: The water droplets in the clouds become heavy and fall back to the Earth as rain, snow, sleet, or hail. 4. Collection: The water collects in bodies of water like rivers, lakes, and oceans, and the cycle starts again.

Answer 56

If the binding energy of an atom is high, it means that the nucleus is very stable. Binding energy is the energy required to separate all the protons and neutrons in the nucleus. A high binding energy indicates that the nucleus is tightly bound and less likely to break apart or undergo radioactive decay. For example, iron-56 has one of the highest binding energies per nucleon, making it very stable compared to other elements.

Answer 57

Earth's atmosphere began to become oxygenated during the Proterozoic Eon. This significant change, known as the Great Oxygenation Event, occurred around 2.4 to 2.3 billion years ago when cyanobacteria started producing oxygen through photosynthesis, gradually increasing the oxygen levels in the atmosphere.

Answer 58

A mantle plume is an upwelling of abnormally hot rock within the Earth's mantle. This hot rock rises from deep within the mantle, possibly from near the core-mantle boundary, and can cause volcanic activity when it reaches the Earth's surface. An example of a mantle plume is the one beneath Hawaii, which creates the volcanic islands in the middle of the Pacific Ocean.

Answer 59

Infrared waves are a type of electromagnetic radiation with wavelengths longer than visible light but shorter than microwaves. They are often associated with heat, as objects emit infrared radiation based on their temperature. For example, infrared waves are used in remote controls for TVs and in thermal imaging cameras to see heat patterns.

Answer 60

An angiosperm is a type of plant that produces flowers and seeds enclosed within a fruit. Angiosperms are the largest group of plants and include a wide variety of species, from grasses and trees to flowers and shrubs. For example, apple trees, roses, and wheat are all angiosperms.

Answer 61

A sporophyte is the diploid, spore-producing phase in the life cycle of plants and algae that undergo alternation of generations. It develops from the fertilized egg, or zygote, and produces spores through meiosis, which can then grow into the haploid gametophyte phase. For example, in ferns, the leafy plant that we commonly see is the sporophyte.

Answer 62

Haploid and diploid refer to the number of sets of chromosomes in a cell: Haploid (n): A cell with one complete set of chromosomes. This is typically seen in sex cells (gametes), such as sperm and eggs in animals, and spores in plants. For example, human gametes each have 23 chromosomes. Diploid (2n): A cell with two complete sets of chromosomes, one from each parent. Most body cells (somatic cells) are diploid. For example, human body cells have 46 chromosomes, 23 pairs.

Answer 63

Transpiration is the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems and flowers. It is a passive process that requires no energy expense by the plant.

Answer 64

Subduction is a geological process where one tectonic plate moves under another and sinks into the mantle as the plates converge. This process typically occurs at convergent boundaries where an oceanic plate is forced below a continental plate or another oceanic plate. Subduction zones are associated with volcanic activity, earthquakes, and the creation of deep ocean trenches. An example of a subduction zone is the area along the Pacific Ring of Fire, where the Pacific Plate is being subducted beneath other surrounding plates.

Answer 65

The order of taxonomic classifications, from the broadest to the most specific, is: Domain Kingdom Phylum Class Order Family Genus Species A handy acronym for remembering the order of taxonomic classifications is: "Dear King Philip Came Over For Good Soup."

Answer 66

Precession is the slow, gradual change in the orientation of an astronomical body's rotational axis. For Earth, this means that the axis slowly traces out a cone over a period of about 26,000 years. This movement affects the position of the celestial poles and the timing of the seasons over long periods. For example, due to precession, the star Polaris will not always be the North Star; eventually, another star will take its place.

Answer 67

Atmospheric turbidity refers to the haziness or cloudiness in the atmosphere caused by the presence of suspended particles and pollutants, such as dust, smoke, and aerosols. These particles scatter and absorb sunlight, reducing the clarity and brightness of the sky. High atmospheric turbidity can lead to reduced visibility and affect weather and climate by influencing the amount of solar radiation that reaches the Earth's surface.

Answer 68

Vasodilation occurs under several circumstances, primarily as a response to increased body temperature, low oxygen levels, or the presence of certain chemicals and hormones. Here are some specific situations: 1. Increased Body Temperature: When you're hot, blood vessels near the skin surface dilate to help release heat and cool the body down. For example, when you exercise, your face might turn red due to vasodilation. 2. Low Oxygen Levels: If tissues need more oxygen, blood vessels dilate to increase blood flow and deliver more oxygen. This can happen at high altitudes where the air has less oxygen. 3. Chemical Signals: Certain substances like nitric oxide, produced in the body, cause blood vessels to dilate. Medications like nitroglycerin, used to treat chest pain, also cause vasodilation. 4. Inflammation or Injury: During an inflammatory response or injury, vasodilation occurs to increase blood flow to the affected area, bringing immune cells and nutrients for healing. These processes help regulate body temperature, ensure sufficient oxygen supply, and facilitate healing and immune responses.

Answer 69

Vasoconstriction, the narrowing of blood vessels, occurs under various circumstances to regulate blood flow and maintain blood pressure. Here are some specific situations: 1. Cold Temperatures: When you're cold, blood vessels constrict to conserve heat and maintain core body temperature. For example, your fingers might turn pale when you're in a cold environment. 2. Stress or Fear: During a "fight or flight" response, stress hormones like adrenaline cause vasoconstriction to redirect blood flow to essential organs and muscles. 3. Low Blood Pressure: To increase blood pressure, the body can constrict blood vessels, ensuring that vital organs receive enough blood and oxygen. 4. Dehydration: When the body is dehydrated, blood volume decreases, and vasoconstriction helps maintain blood pressure and ensure blood flow to critical areas. 5. Medications: Certain medications, such as decongestants, cause vasoconstriction to reduce swelling and congestion in nasal passages. These processes help the body adapt to various conditions, maintaining homeostasis and ensuring that critical organs function properly.