General Science Flash Card Set 897470

Cards 10
Topics Classification of Life, Cytoplasm, Genes, Geologic Time Scale, Heart, Medulla, Power, Pulmonary Artery & Vein, Refraction, Weight

Study Guide

Classification of Life

Classifications of life are too numerous to enumerate, here's an overview of the classifications from broadest to narrowist:

Classification Contains Related
Kingdom phyla
Phylum classes
Class orders
Order families
Family genera
Genus species
Species organisms

Cytoplasm

The nucleus of a eukaryotic cell contains the genetic material of the cell and is surrounded by cytoplasm which contains many organelles. These include:

Organelle Function
ribosomes produce proteins
mitochondria produce energy
endoplasmic reticulum helps synthesize proteins and fats
Golgi apparatus prepare proteins for use
lysosomes help the cell manage waste
centrosomes guide cell reproduction

Genes

The gene is the base unit of inheritance and is contained within DNA. A gene may come in several varieties (alleles) and there are a pair of alleles for every gene. If the alleles are alike, a person is homozygous for that gene. If the alleles are different, heterozygous.

Geologic Time Scale

The Earth is approximately 4.6 billion years old and its history is divided into time periods based on the events that took place and the forms of life that were dominant during those periods. The largest graduation of time is the eon and each eon is subdivided into eras, eras into periods, periods into epochs, and epochs into ages.

Heart

The heart is the organ that drives the circulatory system. In humans, it consists of four chambers with two that collect blood called atria and two that pump blood called ventricles. The heart's valves prevent blood pumped out of the ventricles from flowing back into the heart.

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.

Power

Power is the rate at which work is performed or work per unit time: \(P = {w \over t}\) and is measured in watts (W).

Pulmonary Artery & Vein

The two largest veins in the body, the venae cavae, pass blood to the right ventricle which pumps the blood to the lungs through the pulmonary artery. Blood picks up oxygen in the lungs and returns it to the left atrium via the pulmonary vein.

Refraction

Because different materials have different refractive indices, light changes speed when passing from one material to another. This causes the light to bend (refraction) at an angle that depends on the change in refractive index between the materials. The greater the difference, the higher the angle of refraction.

Weight

Weight is a force that describes the attraction of gravity on an object. Force is measured in newtons (N) with 1 N being the force required to impart an acceleration of 1 m/s2 to a mass of 1 kg.