Classification

classify: to group things together based on similarities.

trait: a feature that a thing has.

kingdom: the largest group of living things.

phylum: the largest group within a kingdom.

class: the largest group within a phylum

order: the largest group within a class.

family: the largest group within an order.

genus: the largest group within a family.

species: the smallest group of living things.

scientific name: genus and species names together

moneran: one-celled organism that don't have a nucleus.

protist: mostly one-celled organisms that have a nucleus and other cell parts.

fungi: organism that have cell walls and absorb food from their surroundings.

plant: multi-cellular organisms that have chlorophyll, and can make their own food.

animal: multi-cellular organisms that can't make their own food, and can move.

Feature of life and the cell

The Study of life

Biology : The of living things and onced-living things.

 Light Microscope: Light passes through the object being looked at and then through two or more lenses.

Stereomicroscope: used for viewing large objects and things through which light cannot pass.

 

International System of units: A meausring system based on unit.

Meter : An SI unit of mass.

Volume : The amount of space  a substance occupies .

Kilogram: Ab SI unit of mass.

Celsius : A scale with wich scientist measure sentences.

Scientific method :series of steps used by scientists

 

hypothesis: a statement that can be tested.

experiment: testing an hypothesis using a series of steps with controlled conditions.

variable:  something that causes the changes observed in an experiment.

control: a standard for comparing results.

data: recorded facts or measurements from an experiment.

theory: a hypothesis that has been tested again and again by many scientists, with similar results each time.

technology: the use of scientific discoveries to solve everyday problems.

The Nervous System

Parts of the neuron

Signal or impulses,are electriacal signals are electrical impulse.
Impulses flash along individual nerve cell or neurons.
Each neuron have three main parts.A cell body dentrites and
an axon.Dentrites are a branching  nerve fiber that carry impulses

toward the cell body. An axon is a nerve fiber that carries impulses
away from the cell body.

Ehen an impulse reach the tip of an axon ,another nerve cell can`t
pick up directly.That`s beacuse there is a gap between neurons.
This gap is called a synapse and it is a only tiny fraction of an  inch wide.

Using What We`ve Learned

Human chromosomes carry genes that control a variety of traits.
Humans have 23pairs chromosomes. One of those pairs
determine the sex of a person.

Female inherited two X chromosomes, one from each parent.

Males inherited one X from one parent and one Y chromosomes from the other.
Only males have a Y chromosomes.

Inheritetance can be controlled by crossing plants or animals to produce offspring
with ceirtain deliberate trait. People have used selective breeding for centuries to produce
better crops, hardier domestic animals, and prettier flower.

How Heredity Works

Gregor Mendel realized that all organisms get two copies of each factor.

Today scientist  call these  factors gene ,

A Gene is the portion of a chromosomes  that controls a particular trait.

Genes are a portion of along , complex molecule called

deoxyribounucleic acid. (DNA).

The codes that the DNA contain are related to the molecules shape

and structure.

Predicting Traits

When two parents have a child , there is about a probability chance the child would have the same characteristics of one parent .

Mendel experiments use a new idea to use the Punnnett Square.

It is a table used to predict the outcome of crossing
 different forms of trait.

To make a Punnett square , draw a large square and 

divide it into four  smaller squares .

Write the parent`s factor for the trait outside the square.

Actually you don`t inherit traits .You inherit factors for traits .Humans inherit thousands of factors for traits from their parents.The color of your hair and skin , the shape of your chin, the color of your eyes,the thickness of your eyebrows, the size  of your feet  and even your height were determined by factors you inherit from each parent.

A chart to trace the the history of traits in a family is called pedigree.