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Biology 1101 Exam 2 Review SP 22

Terms in this set (50)

Who discovered the structure of DNA?
James Watson and Francis Crick
What are the three major parts of DNA?
Sugar, Nucleotides, and a Phosphate Backbone
What bases pair together in DNA?
A-T
G-C
What nucleotide is only found in RNA?
Uracil
What is a cell's genome?
all the DNA in a cell
What is transcription?
The process of making mRNA from DNA
What is translation?
the decoding of an mRNA message into a protein
What is a codon and where is it found?
Found on an mRNA, and three bases on the mRNA which code for an amino acid
What are the start and stop codons?
Start: AUG
Stop: UAA, UAG, UGA
Where does transcription occur?
inside the nucleus
Where does translation occur?
ribosomes in the cytoplasm
What do vaccines usually contain?
An inactive virus or viral proteins
What happens when you get a vaccine?
Your body develops antibodies to fight off specific antigens from the injected virus RNA
What are different types of mutations?
insertion, deletion, substitution, and frameshift mutations
Why do cells not express all of their genes all of the time?
Protein synthesis requires a lot of energy, and would code for unnecessary traits
How do histones prevent DNA transcription/translation?
It binds DNA too tight to be read, so mRNA cannot be created
What are factors that impact your epigenome?
Stress, diet, behavior, illness, physical activity, social interactions, age, inheritance of epigenetic tags
Why do cells divide?
growth, repair, reproduction (Meiosis)
What are the products when a cell divides via mitosis?
Two genetically identical cells (diploid)
What are the products when a cell divides via meiosis?
Four genetically unique cells (haploid)
What are S phase in cell division?
The replication of DNA before cell division
What are the phases of mitosis?
prophase, metaphase, anaphase, telophase
What happens when cells do not follow typical checkpoints in division?
Cells that do not divide properly often become cancerous
How do cancer cells differ from normal cells?
They override cell checkpoints and divide continuously
What are telomeres?
DNA at the tips of chromosomes that break down as cells divide
What are homologous chromosomes?
paired chromosomes with genes for the same traits arranged in the same order
How many chromosomes do humans have?
46 (23 pairs)
What is the difference between autosomes and sex chromosomes?
Autosomes are the first 22 pairs, and sex chromosomes are the X and Y chromosomes
What is separated in meiosis one?
Homologous chromosomes
What is separated in meiosis two?
sister chromatids
How does crossing over contribute to genetic diversity?
It results in inherited chromosomes being unique from the original chromosomes
What is it called when chromosomes fail to separate during meiosis?
Chromosomal nondisjunction (results in aneuploidy)
What was a typical Mendel experiment?
Mendel would breed two pure (homozygous) plants and study the phenotype of the resulting generation
What does it mean for a trait to be dominant?
It first appears or is visibly expressed, and will mask the expression of a recessive allele
What does it mean to be homozygous?
having the same alleles for a trait
What does it mean to be heterozygous?
when both alleles are different. Ex. Aa, Bb
What is the difference between genotype and phenotype?
Genotype are the alleles in your genome, and phenotype is the physical traits you can observe
What happens to proteins made from recessive alleles?
They are typically nonfunctional
What is codominance?
when both alleles contribute to the phenotype
What is incomplete dominance?
A blending of traits. Red+White=Pink.
What is epistasis?
the suppression of the effect of one such gene by another.
What is polygenic inheritance?
inheritance pattern of a trait that is controlled by 2 or more genes
What are GMOs? What are common GMO foods?
Genetically modified organisms ex. Corn and soy plants
What is recombinant DNA?
DNA that contains genes from more than one organism
What are some uses of transgenic organisms?
producing nutritious food, hardy crops, manufacturing pharmaceuticals, and improving human health
What are STR's?
short tandem repeats of sections of DNA that are different in humans
What are the requirements for gene therapy?
the disease must be due to defects in a single gene, the sequence of a normal allele must be known, and a method to introduce the normal gene in must be available
What is CRISPR-Cas9?
A system that allows precise genome editing by cutting out DNA and inserting new DNA in its place.
What is xenotransplantation?
the process of grafting or transplanting organs or tissues between members of different species
What is the shape of DNA referred to as?
A Double Helix
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