Genetics and Heredity Study Guide-7th grade life science

heredity
The passing of genetic traits from parent to offspring
genetics
The science of heredity and of the mechanism by which traits are passed from parents to offspring
allele
One of the alternative forms of a gene that governs a characteristic, such as hair color
dominant
A term that describes the allele that determines the phenotype of an individual organism when two different copies are present in the genotype.
recessive
A term that describes an allele that is not expressed when combined with a dominant form of the gene.
homozygous
Descibres an individual that has identical alleles for a trait on both homologous chromosomes
heterozygous
Describes and individual that has two different alleles for a trait
genotype
The name for the genes an organism has and they are not always obvious.
phenotype
An organism’s appearance or other detectable characteristic that results from the organism’s phenotype and they can be observed such as height, and shoe size.
Punnett Square
A graphic used to determine the results of a genetic cross
probability
The likelihood that a possible future event will occur in any given instance of the event; the mathematical ratio of the number of times one outcome of any event is likely to occur to the number of possible outcomes of the event
Gregor Mendel
The Father of Genetics
What type of plant did Mendel study?
pea plant
Hybrid
offspring that are the result of mating between two genetically different kinds of parents–the opposite of purebred.
Purebred
offspring that are the result of mating between genetically similar kinds of parents–the opposite of hybrid. Purebred is the same as true breeding.
What is selective breeding?
The process of selecting and breeding parent organisms to pass on particular traits to the offspring.
Why did Mendel study what he did?
they were all controlled by a single gene and each of the genes was on a different chromosome.
What case letter represents a dominant gene
uppercase
What case letter represents a recessive gene?
lowercase
What letter combination would tell you if something is purebred?
two uppercase or two lowercase
Why is DNA important?
It contains a code that a cell uses to put together all the material it needs to function properly.
How many sex cells are made during meiosis?
4 sex cells
What are meiosis sex cells called?
In meiosis what happens to the number of chromosomes?
reduced by half. Each parent contributes one chromosome.