Modern Biology Flashcards - L4_ Genetics
field of biology devoted to understanding how characteristics are transmitted from parents to offspring.
Genetics
science of HEREDITY and VARIATION.
Genetics
The passing down of traits in the form of genes from parents to their children
Heredity
It is the difference in genes between individuals or groups of individuals.
Variation
a specific characteristic that varies from one individual to another.
Trait
different possibilities for a given trait.
Alleles
Every trait has at least how many alleles?
2
sequence of DNA that codes for a protein and thus determines a trait.
Gene
Father of Genetics
Gregor Mendel
He Identified specific traits in the garden pea and studied them from one generation to another.
Gregor Mendel
3 Laws of Mendel
Law of Dominance, Law of Segregation, Law of Independent Assortment
In this law, Hybrid offspring will only inherit the dominant trait in the phenotype.
Law of Dominance
In this law, two alleles for each trait separate when gametes form, and parents pass only one allele for each trait to each offspring.
Law of Segregation
It is when the two parent differ from one another by ONE trait
Monohybrid Cross
states that the alleles of different genes are inherited independently within the organisms that reproduce sexually.”
law of independent assortment
Independent assortment takes place during the process of ___
Meiosis
states that during a haploid. DIHYBRID CROSS (crossing of two pairs of traits), an assortment of each pair of traits is independent of the other.
law of independent assortment
The genetic make up of an organism
Genotype
The gene combination an organism has
Genotype
The way an organism looks
Phenotype
The physical characteristics of an organism
Phenotype
term used to refer to an organism that has two identical alleles for a particular trait
homozygous
term used to refer to an organism that has two different alleles for the same trait
heterozygous
When one allele is NOT completely dominant over another (they blend)
Incomplete Dominance
It is when both alleles are expressed
Codominance
determines body traits
autosomes
Inability to distinguish between certain colors.
colorblindedness
A condition wherein blood won’t clot
hemophilia
Graphic representation of how a trait is passed from parents to offspring
Pedigree
In a pedigree, what shape represents female?
Circle
In a pedigree, what shape represents male?
Square
In a pedigree, horizontal lines connecting a male and a female represent a ____
marriage
In a pedigree, this indicates a person has the trait
shaded circle or square
In a pedigree, partial shade represents a ____
carrier
When one gene mutation results in two or more seemingly unrelated observable traits.
Pleiotropy
describes a certain relationship between genes, where an allele of one gene hides or masks the visible output, or phenotype, of another gene.
Epistasis
It can be seen in the coat color of Labrador retrievers.
Epistasis
a picture of an individual’s chromosomes. It can be used to diagnose chromosomal disorders.
Karyotype
a chromosome that is directly involved in determining the sex of the individual.
sex chromosome
47 chromosomes, extra chromosome at pair #21
Down syndrome
47 chromosomes, extra X chromosomes (XXY) that mainly affects boys, having low testosterone levels, underdeveloped muscles, sparse facial hair
Klinefelter’s syndrome
only 45 chromosomes, missing a sex chromosome (X), Girls affected - short, slow growth, heart problems
Turner’s syndrome
a stable, heritable change in the genetic material.
Mutation
Any change in the sequence of nitrogenous bases in the DNA, any mistake in the transcription of genetic information from DNA to RNA or pairing of codon and anticodon
Mutation
In this type of mutation, one base is incorrectly added during replication and replaces the pair in the corresponding position on the complementary strand.
Point mutation or single base pair substitution
an example of genetic disorder that illustrates a dramatic malfunction due to a change in just a single nucleotide in the DNA.
Sickle Cell Anemia
In this type of mutation, extra nucleotides are inserted into replicating DNA, often resulting in a frameshift.
Frameshift mutation by insertion
One or more nucleotides is “skipped” during replication or otherwise excised, often resulting in a frameshift.
Frameshift mutation by deletion
These are associated with random changes that cause errors when DNA is produced in the cell.
Spontaneous Mutation
Mutations may also be induced by environmental factors called ____
Mutagens
It may be in the form of radiation, chemicals, and microbial infection.
Mutagen
This gene mutation involves red blood cells being sickle shaped instead of round and cannot carry enough oxygen to the body tissues - heterozygous condition protects people from malaria
Sickle cell anemia
mucous builds up in the lungs
Cystic Fibrosis
deterioration of the nervous system - early death
Tay-Sachs Disease
an amino acid common in milk cannot be broken down and as it builds up it causes mental retardation - newborns are tested for this
Phenylketonuria (PKU)
gradual deterioration of brain tissue, shows up in middle age and is fatal
Huntington’s Disease
variety of skeletal abnormalities
Dwarfism
In this process, a very few parent plants are chosen for breeding from a great number of individuals.
mass selection
may be the oldest form of plant breeding.
mass selection
crossing of two different but closely related strains.
Hybridization
the opposite of hybridization.
Inbreeding
Instead of crossing two parent plants, this involves self- pollination of a single parent.
Inbreeding
a condition, in which more than twice the haploid number of chromosomes are present,
polyploidy
Human diseases linked to point mutation/single base pair substitution
Albinism, Sickle Cell Anemia
Human Diseases linked to Frameshift mutation by insertion
One form of beta thalassemia
