BIO 130 Test 2 Flashcards
What is the process where homologous chromosomes pair up during prophase 1 of meiosis
Synapsis
Genetic process that occurs during meiosis when homologous chromosomes exchange genetic material
Crossing Over
A process that restructures part of a genome by exchanging genetic material between DNA molecules
Recombination
A breeding experiment that involved reversing the sexes of parents in a cross to determine the role of parental sex in inheritance
Reciprocal cross
Parental Generation, 1st generation, 2nd generation
P, F1, F2
A genetic theory that explains how phenotypic traits are passed down through generations
Particulate Inheritance
Pairs of alleles, or genes are separated into reproductive cells during meiosis
Principle of segregation
trait or gene that is most influential
Dominant
Trait or gene that is less strong, only shows through if it is homozygous
Recessive
two or more traits are fully expressed and neither is dominant or recessive
Codominant
A genetic phenomenon where a heterozygote phenotype is more extreme than either of its parents phenotypes
Overdominant
Different genes and their corresponding trait are separated independently during the development of reproductive cells
Principles of Independent assortment
A characteristic that is determine by genes located on the sex chromosome
Sex-linked trait
A genetic phenomenon where a single DNA variant, or gene, affects multiple traits that may seem unrelated.
Pleiotropy
A genetic phenomenon where the expression of one gene is modified by the expression of one or more other genes.
Epistasis
What are the three purposes of mitosis we discussed in class?
Growth, repair, and asexual reproduction
Why is it important to have regulation checkpoints in the cell cycle?
They act at control mechanisms to make sure the cell is fully grown and ready to divide into two cells
What is the evolutionary explanation for sexual reproduction?
Provides genetic diversity within a population
In what two ways does meiosis increase genetic variation?
Crossing over and Independent Assortment
What are the characteristics of a good model organism for genetic studies?
-a large natural population with a wide range of genetic variations
-a short generation time allowing for rapid observations of new mutations
-easily identifiable phenotypic traits linked to genetic variations
-well established genetic tools for manipulating and analyzing the genome
-a species with a high level of genetic diversity that is also convenient to study in a laboratory setting
Explain Mendel’s model of particulate inheritance
Genetic traits are passed from parent to offspring as discrete units called “particles” meaning that traits are not blended together but inherited as distinct entities
Cell cycle and phases
A series of events that a cell goes through to divide into two new daughter cells
-G1
-S
-G2
-Interphase
-Prophase
-Metaphase
-Anaphase
-Telophase
-Cytokinesis
Mitosis
A process where a single cell divides into two genetically identical daughter cells
Meiosis
A type of cell division that occurs in sexually reproducing organisms to produce gametes, or sex cells like eggs and sperm
Chromsome
The “X” structure carrying DNA
Sister Chromatids
The chromatids that have paired together
Homologous chromosomes
The “XX” structure where one comes from mom and one comes from dad
Ploidy
The number of copies of chromosomes found in each nucleus in a given organism
Autosome
Any chromosome that is a sex chromosome
Transformation
the process where a cell takes up and incorporates foreign genetic material from its surroundings
Semiconservative Replication
the process by which DNA is copied in cells to create two new double-stranded DNA molecules, each with one original strand and one new strand
DNA Polymerase
Replicates DNA
Leading Strand
The strand of nascent DNA which is synthesized in the same direction as the growing replication fork
Lagging Strand
One of two strands of DNA that are found at the replication fork, or junction, in the double helix
mRNA
Messenger RNA is a single stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of synthesizing a protein
5’ CAP
Protects the mRNA, helps export out of cell, and promotes translation
Poly-A-Tail
Makes the mRNA molecule more stable and prevents its degration
Introns
the segment of DNA that does not code for proteins, gets spliced out
Exons
the segment of DNA that codes for the protein, turns into the mature RNA strand
Splicesomes
large ribonucleoprotein complexes that remove introns from pre-mRNA to create a translatable molecule
RNA polymerase
An enzyme that functions by copying a DNA sequence into an RNA sequence
Template strand
the strand of DNA that serves as the pattern for building a complementary RNA molecule during the process of transcription
Promotor
A DNA sequence that marks the beginning of a gene’s transcription
Terminator
a sequence of nucleotides that marks the end of a gene or operon during transcription
Transcription Factors
A protein that binds to specific DNA sequences on a gene to regulate the rate at which that gene is transcribed into RNA
Ribosomes
a complex molecular machine found within cells, responsible for protein synthesis by translating the genetic code carried by messenger RNA into a chain of amino acids, which then fold to form proteins
Ribozyme
a ribonucleic acid molecule that can catalyze chemical reactions, similar to an enzyme
rRNA
a fundamental component of ribosomes, which are molecular machines that translate genetic information into proteins
Codon
a sequence of three DNA or RNA nucleotides that correspond with a specific amino acid or stop signal during protein synthesis
Anticodon
a sequence of three nucleotides in transfer RNA that matches a specific codon in messenger RNA during protein synthesis