Final Exam Review- Genetics Flashcards
Define : hybrid
A genotype with two different alleles.
Define : trait
characteristics that varies from person to person
Define : purebred
genotype with the same alleles
Define : dominant
The trait that posses more power of the other
Define : recessive
The trait that posses less power over the other
Define : phenotype
What an organism looks like.
Define : genotype
genetic makeup of an organism
Define : hetereozygous
having two different alleles for a trait
Define : homozygous
two identical alleles for a trait
Define : incomplete dominance
creates a blended phenotype; one allele is not completely dominant over the other
Define : codominace
both alleles of a gene contribute to the phenotype of the organism
Define : polygenetic traits
A trait controlled by 2 or more gene pairs
Define : multiple alleles
There are 3 or more alleles for a trait in the population
ex- human blood types
Define : chromosome
a condensed bundle of chromatin that appears during cell division ; contains the DNA of the cell
Define : gene
DNA that codes for a specific trait
Define : codon
The three nitrogenous bases in RNA or DNA that code for amino acids
Define : anticodon
the 3-base-pair codon that binds to a complimentary piece of mRNA during protein synthesis
Define : allele
different forms of a gene
What is the difference between sex-linked traits, sex-limited traits, and sex-influenced traits? Give examples of them.
Sex-Limited traits: an autosomal trait expressed in only 1 sex
Sex-linked trait: a trait determined by the sex chromosomes
sex-influenced: a trait found in both sexes expressed differently in each
What are the structures and bases of DNA and RNA?
RNA- Double Helix
- Adenine, thymine , cytosine , guanine
DNA- Single Helix
- Adenine , uracil, cytosine , guanine
Define : linked genes
Genes that are on the same chromosome
Define : genetic recombination
When crossing over moves genes into new combinations
Define : recombinant
An organism or chromosome with a recombined set of genes
Define : sex chromosome
chromosomes that determine the sex of the organism
Define : mutation
a spontaneous change in a gene or chromosome
Define : autosomes
any chromosome other than the sex chromosomes
Define : karyotype
a photograph showing an individuals chromosomes in homologous pairs
Define : Chromosome Mutations
deletion duplication translocation inversion nondisjunction monosomy trisomy polyploidy
Define : deletion
one or more genes may be lost entirely from a chromosome during division
Define : duplication
When a chromosome receives an extra duplicate piece from its homologous partner
Define : translocation
a whole chromosome or piece of a chromosome attaches to a chromosome a different way
Define : inversion
a fragment of a chromosome may break free, turn completely around, and reattach itself upside down
Define : nondisjunction
the failure of chromatids or chromosomes to separate during cell division
Define : monosomy
the zygote only receives only one of a particular type of chromosome instead of 2
Define : trisomy
the zygote receives 3 chromosomes of a particular type instead of 2
Define : polyploidy
non-dis junction occurs in all the pairs of chromosomes at once
Define : transformation
a process by which bacterial cells incorporate DNA from dead bacterial cells
Define : gene mutation
A change of nucleotides within a gene
Define : point mutation
When one pair of bases is replaced with a gene
Define : deletion mutation
the loss of one or more bases from the DNA of a gene
Define : addition mutation
one or more bases is added to the DNA of a gene.
Define : mutagen
How does a carcinogen relate to it?
factors in the environment that cause mutations to occur.
Mutagens that affect genes controlling growth and differentiation may result in cancer. the ability of chemicals to cause cancer is linked to their ability to cause mutations
Define : plasmids
Small circular pieces of DNA within bacteria
Define : vector
a carrier of genetic material used in genetic engineering
Define : eugenics
a practice that seeks to change human heredity by controlling mating.
Explain how gene mapping works.
finding the location of genes of chromosomes
Why do you think recessive sex-linked traits are more common in male than female?
Because men only need 1 recessive trait whereas females need 2
In point form, summarize how DNA replication occurs.
- DNA double helix unwinds
- bases begin to split apart , separating strands
- free-floating nucleotides are preset in the nucleus
- DNA polymerase moves along each strand and matches up free-floating nucleotides with the correct bases
- results in 2 identical DNA molecules
Where are proteins made? Why is that a problem?
ribosomes
because the instructions are in the nucleus and the proteins are made in the ribosomes so theyre in complete different places
Name the 3 types of RNA.
DNA
mRNA
tRNA
Which 2 processes make up Protein Synthesis?
Transcription& Translation
In point form, summarize the process of transcription.
- part of the DNA with the instructions unwind and bases separate
- only 1 strand of DNA is needed because its single stranded
- the enzyme RNA polymerase brings free-floating nucleotides to the strand of open DNA
- process results in a strand of mRNA being formed
- the mRNA can now leave the nucleus
In point form, summarize the process of translation.
- mRNA attaches to a ribosome
- tRNA with the matching anticodon brings the right amino acid
- mRNA moves along the ribosome, more tRNA moves along the ribosome, more amino acids that end up forming a protein
Which of the 3 types of gene mutation is the least harmful? Why?
point , because only 1 base is replaced
What are DNA fingerprints used for?
determining the biological parent to identifying the suspect of a crime.
In DNA fingerprinting, what are restriction enzymes used for?
They cut the long DNA molecules at different locations. Where it cuts depends on the code within the DNA molecule and the code within the enzymes
In DNA fingerprinting, which chemical is radioactive?
x-ray film
In Karyotyping, which areas of the chromosome stain as a dark band?
The dye stains regions of chromosomes that are rich in the base pairs of Adenine and Thymine producing a dark band
What is the difference between inbreeding and outbreeding?
Inbreeding- the crossing of parents that have similar genotypes
Outbreeding: the crossing of distantly related relatives
Is polyploidy more dangerous in plants or animals?
Animals- it is rare in aniamls and is almost always lethal when it does occur
What is one substance produced using genetically engineered plasmids?
insulin
