General Science Flash Card Set 938009

Cards 10
Topics Cell Division, Cell Membrane, Endoskeleton, Medulla, Number System, Respiration, Thermosphere, Third Law of Motion, Velocity, Work

Study Guide

Cell Division

Cell division is the process by which cells replicate genetic material in the nucleus. Cell division consists of several phases:

Phase Major Process
interphase chromosomes replicate into chromatids and the cell grows
prophase chromatids pair up
metaphase paired chromatids move to opposite sides of the cell
anaphase cell elongates and nucleus begins to separate
telophase separation of nucleus is complete resulting in two new nuclei
cytokinesis cytoplasm and cell membranes complete their separation resulting in two separate cells
Cell Membrane

Animal cells are surrounded by a semipermeable membrane which allows for the transfer of water and oxygen to and from the cell. In plant cells, the cell membrane is surrounded by a somewhat rigid cell wall which provides the cell structure and support.

Endoskeleton

An endoskeleton (internal skeleton) is a charateristic of vertebrate animals, including humans.

Medulla

Part of the brainstem, the medulla is the connection between the brain and the spinal cord. It controls involuntary actions like breathing, swallowing, and heartbeat.

Number System

The metric system is a number system that designates one base unit for each type of measurement. For example, the base unit for length is the meter and the base unit for mass is the gram.

Respiration

The respiratory system manages respiration which is the process by which blood cells absorb oxygen and eliminate carbon dioxide.

Thermosphere

Temperatures again increase with altitude in the thermosphere which is the hottest (4,530 °F / 2,500 °C) atmospheric layer due to direct exposure to the Sun's radiation. However, the gas in this layer is highly diluted so even though the atoms of gas may be very high in temperature, there are too few of them to effectively transfer much heat.

Third Law of Motion

Newton's third law of motion states that For every action, there is an equal and opposite reaction. When an object exerts a force on another object, the second object exerts a force of equal magnitude in the opposite direction on the first object.

Velocity

Velocity is the rate at which an object changes position. Rate is measured in time and position is measured in displacement so the formula for velocity becomes \(\vec{v} = { \vec{d} \over t } \)

Work

Work is performed on an object when an applied force causes displacement along the same vector. Measured in joules (J) or newton-meters (Nm), work is calculated by multiplying force times displacement: \(W = \vec{F}\vec{d}\)