Embryology Flashcards
What is DNA?
Transmits genetic code to the next generation
Unit of heredity
What is RNA?
Copies the code from DNA (transcription) and translates it into amino acids
Point between DNA and amino acid production
What are the differences between DNA and RNA?
DNA is double stranded and RNA is single stranded
DNA has thymine as a base and RNA has uricil
DNA has one less oxygen molecule than RNA
What nerve, muscle, and skeletal structure develop from the 1st branchial arch?
Trigeminal
Tensor tympani
Incus and malleus
What nerve, muscle, and skeletal structure develop from the 2nd branchial arch?
Facial
Stapedius
Stapes
What is gastrulation?
The development of the 3 germ layers
Development form a blastocyst to a gastrula
What are the 3 germ layers?
Endoderm, mesoderm, and ectoderm
What develops from the endoderm?
Epithelial lining of the ET
Epithelial lining of GI tract
What develops from mesoderm?
Vascular system (heart, valves)
Bone (ossicles)
Smooth muscle
What develops from ectoderm?
PNS
CNS
Epidermis
Review embryonic development of the inner ear and cochlea
What are 2 similarities of mitosis and meiosis?
Same division phases
Both double number of chromosomes they have before division
What are 2 differences of mitosis and meiosis?
Mitosis produces 2 identical daughter cells and meiosis produces 4 non-identical cells
Mitosis only has one division stage
What are some 1st and 2nd arch syndromes?
Pierre Robins
Stickler
Treacher Collins
What are some main characteristics of 1st and 2nd arch syndromes?
Small/abnormal ear
Small lower jaw
Cleft lip with or without palate
What are epigenetics?
Environmental effects on genes
Most cancers
What is missense non-conservative mutation?
A point mutation where it changes the amino acid that is supposed to go there
Doesn’t do a similar function
What is transcription?
Exact copy of the code
What is translation?
Translating code into amino acids
Cochlear hair cells once fully differentiated, remain in the _______ phase of the cell cycle?
G0
What is a point mutation that prematurely codes for a stop codon?
Nonsense mutation
Genetic crossing over in _______ prevents children form being clones of parents
Prophase 1
What are the stop codons?
UAA
UAG
UGA
Which neural tube defect contains remnants of all three germ layers?
Dermoid cyst
What is the primary function of meiosis?
Combining genetic material from egg and sperm to prevent offspring from being clones of parents
Providing haploid number of chromosomes to germ cells
Does meiosis 2 end with 4 daughter cells with 46 chromosomes?
No, they are haploids
Does DNA structure allow for replication and affords protection against DNA loss and damage?
Yes
What do sperm not contribute? Why?
Mitochondria
Shed cytoplasm
Is a zygote a diploid?
Yes
What does the ET develop from?
The first pharyngeal pouch
What does the EAM develop from?
The first pharyngeal groove
What does the pinna develop from?
Auricular hillocks
What does the inner ear develop form?
Otic placode of the ectoderm
What are adenine and guanine?
Purines (two ring)
What are cytosine and thymine?
Pyramidines (one ring)
What are differences between AD and AR?
AR requires a copy of 2 identical genes
AD has vertical transmission
AR is impacted by consanguinity
AR traits have a 25% chance of being passed down, and AD have a 50% chance
What is an eve gene?
A mitochondrial gene
What is homozygous/
2 identical alleles for one gene
What is genomic imprinting?
Phenotype of a mutation is determined or impacted by who it was passed by
Prader willi - paternal
Angelman - maternal
What is a phenocopy?
An environmental trait that mimics a genetic trait
Hair loss from chemo is a phenocopy of alopecia
For an offspring to inherit an AR condition, does the parent need to be an obligate carrier?
Yes
What is complementary mating?
Not the same deafness gene
Hearing children
What is huntington’s disease an example of?
Genetic anticipation and allele expansion
Does x-linked transmission have male to male transmission?
No
Do chromosomal abnormalities typically adversely affect several different systems and structures?
Yes
Do most people with an unequal number of chromosomes demonstrate growth deficits and intellectual disability?
Yes