Ch. 10, 11, 12, 13 & 15, Patterns of inheritance, Chromosomes and human genetics, DNA, From Gene to protein, DNA technology Flashcards
Father of genetics
Gregor Mendel
Genetic traits
Patterns in which inherited characteristics, or _____ are passed from parent to offspring
A stretch of DNA that governs one or more genetic traits
Gene
The display of a particular version of a genetic trait in a specific individual is the ____ of that individual
Phenotype
They possess two copies of each type of chromosome
Diploid
Two members of the specific chromosome pair found in diploid cells, one of which comes from the individual’s mother and the other from its father
Homologous chromosome pair
in a homologous pair of chromosomes, the one that comes from the mother
Maternal homologue
In a pair of homologous Chromosomes, the one that comes from the father
Paternal Homologue
The sex cells have only one set of chromosomes, that is, half the total number of chromosomes found in a diploid cell
Haploid
Different versions of a given gene are known as
Alleles
Of an individual is the allelic makeup of that individual leading to a particular phenotype
Genotype
An individual who carries two copies of the same allele is said to be a
Homozygote
An individual whose genotype consist of two different alleles for a given phenotype is a
Heterozygote
The allele that exerts a controlling influence on the phenotype, to the point of masking the effect of a second allele it is paired with, is said to be
Dominant
The first generation of offspring in a genetic cross
F1 generation
The second generation of offspring in a genetic cross
F2 generation
A controlled mating experiment, usually performed to analyze the inheritance of a particular trait
Genetic cross
The parent generation in a genetic cross
P generation
an allele That does not have a phenotypic effect when paired with a dominant allele
Recessive Allele
Any inherited feature of an organism that can be measured or observed, height, flower color, or the chemical structure of a protein, are all examples of genetic traits
Trait
Any change in the DNA that makes a gene
Mutation
Two copies of a gene separate during meiosis and end up in different gametes
Law of segregation
it charts how alleles are distributed into gametes by meiosis and combined in all possible ways during fertilization
Punnett Square
We can represent the separation of the two copies of the gene during meiosis, and their recombining through fertilization, using a diagram called a
Punnett Square
Which states that when gametes form, the separation of the two copies (Alleles) of one gene during meiosis is independent of the separation of the copies of other genes
Law of independent assortment
What is the ultimate source of genetic variation in a population of organisms?
Mutations, which are random changes in the coding information in DNA
When neither allele in a heterozygote is completely dominant over the other, a third phenotype may be observed that is intermediate between the phenotypes of the two Homozygous alleles
Incomplete dominance
A pair of alleles can also show _____, in which the effect of both alleles is equally visible in the phenotype of the heterozygote
Codominance
The situation when a single gene influences a variety of different traits is called
Pleiotropy
When the phenotypic effect of the alleles of one gene depends on which alleles are present for another, independently inherited Gene, the phenomenon is known as
Epistasis
They are determined by the action of more than one gene
Polygenic
Allele H produces straight hair, while allele H’ produces curly hair. Individuals with the HH’ genotype have wavy hair, somewhere between straight and curly. Are alleles H and H’ codominant?
No, they display incomplete dominance, since they produce an intermediate phenotype in the heterozygote
The ABO blood groups are determined by several alleles of the I gene. Is this a polygenic trait?
No, ABO blood groups are controlled by a single gene with multiple alleles
What is Pleiotropy?
The phenomenon of a single gene influencing a variety of different traits is called pleiotropy
Explain why this statement is incorrect, Polygenic traits are affected by environmental influences, but single-gene traits are not.
The phenotype of some single gene traits may be environmentally influenced. For example, the temperature-sensitive Ct allele in Siamese cats is one allele of a single gene, C.
What are the four human blood types
A, B, AB, O
PP
Homozygous dominant
Pp
Heterozygous
pp
Homozygous recessive
True breeding parents
Two of the same alleles
The physical location of a gene on chromosome is called a
Locus
The concept that genes are located on chromosomes came to be known as the
Chromosome theory of inheritance
Chromosomes that determine sex are called
Sex chromosomes
All other chromosomes which are not sex chromosomes are called
Autosomes
Functions as a master switch, committing the sex of the developing embryo to male
The SRY Gene, sex determining region of Y
Genetic Loci that our neighbors or his Positioned close to each other on the same chromosome tend to be inherited together and are said to be
Genetically linked
Random segments of the chromosomes are swapped between pairs of homologous chromosomes in a process known as
Crossing-over
Refers to the random distribution of maternal and paternal chromosomes into gametes during meiosis
Independent assortment of chromosomes
Is a chart similar to a family tree that shows genetic relationships among family members over two more generations of the family’s history
A pedigree
A needle is inserted through the abdomen Into the uterus to extract a small amount of amniotic fluid from the pregnancy sac that surrounds the fetus
Amniocentesis
Another method in which a physician uses ultra sound to guide a narrow, flexible tube through a woman’s vagina and into her uterus, where the tip of the tube is placed next to the villi, a cluster of cells that attaches to the pregnancy sac to the wall of the uterus. Cells are removed from the villi by gentle suction, then tested for genetic disorders
Chorionic Villus Sampling (CVS)
One or two cells are removed from the developing embryo, usually three days after fertilization occurs.
Preimplantation genetic diagnosis (PGD)
Heterozygous individuals are said to be
Carriers
Sex linked genes are found on the X chromosome or the Y chromosome-but not both-males receive only one copy of each sex linked genes
Sex-linked
Six-linked genes on the X chromosomes are said to be
X-linked