TRAITS AND HOW THEY CHANGE
NEW BOOK Chapter 2 --- STUDY GUIDE
TRAITS – All of the features that an organism inherits
GENE – A part of the DNA code on a chromosome
GENOTYPE – The genes that an organism has – its genetic makeup
PHENOTYPE – This is the combination of genetic makeup and the environments effect on that makeup
GENETICS – ‘HEREDITY’ is the passing of traits from parents to offspring. Eventually, the study of ‘HEREDITY’ developed into the science of GENETICS.
ALLELE – Different forms of a gene
DOMINANT – Alleles will show their effect on the phenotype whenever they are present in the genotype. In other words, they are seen OFTEN in each generation.
RECESSIVE - Alleles will show their effect on the phenotype ONLY when two of them for a trait are present in the genotype. They are seen less often than dominant traits
PUNNETT SQUARE – Developed by Richard Punnett, this chart can help people understand and make genetic predictions
EVOLUTION- THE GRADUAL CHANGE IN A SPECIES OVER TIME
SPECIES- A GROUP OF SIMILAR ORGANISMS THAT CAN MATE WITH EACH OTHER AND PRODUCE FERTILE OFFSPRING.
ADAPTATION- A TRAIT THAT HELPS AN ORGANISM SURVIVE AND REPRODUCE.
PERHAPS, DARWIN THOUGHT, THE SPECIES GRADUALLY CHANGED OVER MANY GENERATIONS AND BECAME BETTER ADAPTED TO THE NEW CONDITIONS.
NATURAL SELECTION- THE PROCESS BY WHICH INDIVIDUALS THAT ARE BETTER ADAPTED TO THEIR ENVIRONMENT ARE MORE LIKELY TO SURVIVE AND REPRODUCE THAN OTHER MEMBERS OF THE SAME SPECIES
MUTATION – MUTATION is the process in which DNA changes results in new alleles. Basically, it is a sudden change in a genetic code.
ADAPTIVE RADIATION – The production of several species from one ancestral species is called adaptive radiation
EXTINCTION- WHEN NO MEMBERS OF A SPECIES ARE STILL ALIVE
SCIENTIFIC THEORY- A WELL-TESTED CONCEPT THAT EXPLAINS A WIDE RANGE OF OBSERVATIONS
FOSSIL RECORD- THE MILLIONS OF FOSSILS THAT SCIENTISTS HAVE COLLECTED. They give clues to past species.
GRADUALISM- PROPOSES THAT EVOLUTION OCCURS SLOWLY BUT STEADILY.
FURTHER DETAILS:
Chapter 1 - Traits and the environment
Traits are all the features an organism inherits.
Genes are a part of the DNA code on a chromosome.
Genotypes are the genes the organism has.
Phenotypes are the combinations of genetic genes.
Observing traits People observed the inheritance of traits long before scientists understood how the inheritance occurred.
Phenotypes and Genotypes Each traits results from the coded information in the hereditary material called DNA, which is found in every cell.
Growth If you want the plant to grow faster you grow it away from all the others so if can have all sun and water.
Appearance The presence of water makes the difference because a leaf that grows halfway in the water is half threadlife and half broad.
Gender Most animals are male or female but some animals like the clownfish can change sex.
Genetics- are the study of heredity.
Allele- an alternative form that a gene may have for a single trait, can be dominant or recessive.
Dominant- describes a trait that covers over, or dominates, another form of that trait.
Recessive- describes a trait that is covered over, or dominated, by another form of that trait.
Punnett Square- tool used to predict the probability of certain traits in offspring that shows the different ways alleles can combine.
What is genetics? Studies in genetics, combined with an understanding of chemical interactions and other cell processes.
Dominant and Recessive traits How dominant and recessive alleles show their effects has helped scientists figure out how some genetic disease are passed down through families.
Section 3- Environmental impact over time
Evolution- The change in the genetics of a species over time.
Natural Selection-A Process in which organisms that are suited to a particular environment are better able to survive and reproduce than organisms that are Not.
Mutation- The process in which DNA changes resulting in new alleles.
Adaptive Radiation- The production of several species from one ancestral species.
Extinction- Occurs when the last individual of a species dies.