Exam 1 Flashcards
Genetics
Focuses on Heredity and Variation
Centered around genes
Central Dogma
Pathway of gene expression goes from DNA to RNA to protein
Post-Transcriptional Modifications
Alternative splicing
5’-capping w/ methylated guanine
Poly-A tail on 3’
Post-Translational Modification
Phosphorylation, ubiquitination, methylation, acetylation, etc.
Gene
A segment of DNA that holds the molecular information to produce a functional product
Proteome Complexity
Starts very compressed and expands to many options
Many complex steps to make a lot of different things
Chromosome composed of…
2 chromatids
Genetic Variation is…
The root of natural diversity
Gene Expression
Using gene to affect characteristics
Expression Levels
Molecular (protein)
Cellular (structure or working of a cell)
Organism (organism’s traits)
Population (traits within a species)
Allele
Different version of a gene
Morphological
Appearance
Physiological
Ability to function
Behavioral
Response to Environment
True or False
~20,000 protein-coding genes
True
True or False
Approx. 2 million base pairs
False
Approx. 3 million base pairs
Catabolic
Big to small
Anabolic
Small to big
Centromere
Constricted region of the chromosome
Kinetochore
Protein structure near the centromere that spindle fibers attach to during replication
DNA wraps around histones, what amino acids help this?
Lysine and Argenine
Nucleosome
DNA and Histones
G₁
Preparing to divide, once it reaches restriction point, it is committed
S
Chromosome replicated, two copies called chromatids, joined @ centromere
G₂
Gather needed materials for nuclear and cell division
Mitotic Spindle
Organizes and Sorts eukaryotic chromosomes
Formed of microtubule-organizing centers (MTOCs)
So each daughter cell gets same genetic info
Astral microtubules
(top)
Outward from centrosome (top) → plasma membrane, important for position in cell
“Pull” towards ends
Polar microtubules
(middle)
Go → region where chromosomes will be during mitosis (middle): between two spindle poles
“Push” away from e/o
Kinetochore microtubules
Attached to kinetochores
Order of Mitosis
Interphase, Prophase, Prometaphase, Metaphase, Anaphase, Telophase, Cytokinesis
Prophase
Chromosomes already replicated, nuclear membrane begins to dissolve, chromatids condense
Prometaphase
nuclear membrane gone, mitotic spindle
Metaphase
Sister chromatids align themselves (metaphase plate), each pair chromatids attached to poles by kinetochore microtubules, info equally distributed
Anaphase
Each chromatid now indiv. chromosomes, linked to only 1 pole, move to pole they’re attached to, poles move apart due to elongation of polar microtubules
Telophase
Reach poles + decondense, nuclear membrane reforms
Cytokinesis
2 separate daughter cells
Meiosis has __ rounds of division and results in __ _______daughter cells
2 rounds of division, 4 haploid daughters
Order of Prophase 1
Leptotene, Zygotene, Pachytene, Diplotene, Diakinesis
Leptotene
Already condensed, nuclear membrane starting to break
Zygotene
Bivalent, synaptonemal complex (synapsis recognition)
Pachytene
Crossing over, associated chromatids = bivalents
Diplotene
Chiasma, no more synaptonemal complex
Diakinesis
No more nuclear membrane
Synaptonemal Complex (SC)
Forms scaffold that connects two homologous chromosomes, promotes crossing over
Genomic Integrity is…
The defense again mutation
Chiasma
Location of crossing over
Incomplete Penetrance
Dominant allele is present but not expressed
Incomplete Dominance
red + white = pink
Wild-type
Prevalent alleles in natural population
Mutant type
Random mutations, alter preexisting
