Chapters 11 and 16 Flashcards
Chromosome
Structure found inside the nucleus of a cell. A chromosome is made up of proteins and DNA organized into genes. Each cell normally contains 23 pairs of chromosomes.
Diploid
A cell that contains two copies of each chromosomes.
Haploid
Presence of a single set of chromosomes in organisms cells. Sexually reproducing organisms are diploid. In humans, only the egg and sperm cells are haploid.
Homologous chromosomes
Two chromosomes in a pair, normally one inherited from mother and one from the father.
Heredity
The sun of all biological processes by which particular characteristics are transmitted from parents to their offspring.
Genetics
The scientific study of jeans and heredity- of how certain qualities or traits are passed from parents to offspring as a result of changes in DNA sequence.
Gregor Mendel
Worked in 1860’s. Was the first person to analyze patterns of inheritance. Deduced the fundamental principles of genetics.
Traits
Specific characteristics of an individual.
Hybrid
Offspring of parents are different and genetically determined treats. The parents may be of different species, genera, or (rarely) families.
Phenotype
The physical appearance of an organism.
Genotype
The genetic makeup of DNA.
True-breeding
Produces only offspring that express the same phenotype generation after generation.
Crossing
To deliberate breeding of two individuals that results in offspring that carry part of the genetic material of each parent.
P generation
The parental generation are genetically pure individuals.
F1 generation
First filial generation. The initial cross between two genetically distinct plants.
F2 generation
Second filial generation of individuals which arises as a result of inbreeding amongst individuals of F1 generation.
Allele
Alternate versions of the same gene.
Dominant allele
Exert its affect whenever it is present.
Recessive allele
One who’s effects are masked
Homozygous
An organism is homozygous for that allele if both alleles are identical.
Heterozygous
An organism is heterozygous for that gene if the alleles are different.
Homozygous dominant
An organism carries two copies of the same dominant allele.
Homozygous recessive
An organism carries two copies of the same recessive allele.
Locus
The site a gene occupies in the chromosome.
Principle of segregation
Describes how how pairs of gene variants are separated into reproductive cells.
Monohybrid cross
The hybrid of two individuals with homozygous genotypes which result in the opposite phenotype for a certain genetic trait.