BIOL SCI 215 Study Guide - Midterm Guide: Metaphase, Ovule, Chromosome
28 Jun 2018
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Department
Course
Professor
4/3 Introduction to Genetics
20,000 genes in the human genome
- Two main branches
- Prokaryotic cells
- Bacteria
- Unicellular
- “Bag of molecules”
- Eukaryotic cells
- Plants, animals
- Unicellular or multicellular
- Focus on nucleus, mitochondria, etc.
- Proteins are a linear sequence of polymers called amino acids
- Formed through the dehydration reaction
- 20 different amino acids, each have particular R group thus giving them varied
chemical properties.
- This is the reason why proteins can carry out different functions
- Proteins fold into 3-D shapes
- 3-D orientation + amino acid sequence leads to varying chemical properties
- Proteins perform complex functions due to high chemical complexity
- Enzymes catalyze particular chemical reactions by bind to subspecific area
- Protein binding to another protein
- Protein binding with specific DNA sequence
- Most cellular functions are performed by proteins
- Motors move along scaffolds to transport materials within the cells
- Receptors allow for communication between inside and outside of cells
- Mutation in dynamin gene → sequence change in dynamin protein (now slightly unstable
as high temperature unfolds) → neuron communication requires dynamin
- Lower temperature leads to restoration of synaptic connection
- Model organisms allow rapid identification of gene functions relevant for mammalian
biology → hippo gene in fruit flies is a common gene used for suppression of tissue
growth
- Identification of gene led to a discovery of control of growth in humans and
animals
- Have to start learning inheritance first before understanding mechanism as transmission
of disease
4/4
Blended inheritance idea
- Traits could blend together in a fluid fashion
- Idea pre-dated Mendel, traits blend in each generation
Why was Mendel successful?
1) Used a good model organism
a) Pea plants grown and analyzed in large numbers and several varieties had been
found
b) Have good offsprings
c) Easy to grow
d) Plants can cross-fertilize or self-fertilize
i) Plant gametes: Pollen (Male) + ovule (female)
ii) Self: Can occur with a brush or a bag - transfer pollen to stigma which
leads to progeny and plant grows into an adult
iii) Cross: Transfer pollen from one plant to another by removing anthers of
the other plant → progeny → adults
2) Examined “discontinuous character traits”
a) Two distinct phenotypes: appearance/characteristic or trait that can be measured
3) True-breeding strains / Pure-breeding strains/lines
a) Cross it with itself and same population and the generations would be the same
b) Wrinkliness or roundness of a pea
4) Quantified the data
a) First breeding: F0/P(parental generation) - Pure breeding of round and pure
breeding of wrinkly leading to the first generation (F1) being round peas
b) These round peas self fertilize and this leads to F2 being round:wrinkly (3:1)
Mendel builds a model by:
1) Defining players: Round pea gene having 2 alleles: R and r - round = R and wrinkly = r
a) Homozygous - same allele such as rr and RR
b) Heterozygous - different allele = Rr
i) Only one of the alleles is typically “expressed” == shown/displayed
ii) This is denoted by dominant and recessive
iii) [taken as an assumption till later chapters]
2) Need an experiment to determine whether alleles are dominant or recessive
3) You can only know by looking at the phenotype of heterozygotes
F0 or P: RR x rr
P gametes: 100% R, 100% r
F1: Rr x Rr
Document Summary
Proteins are a linear sequence of polymers called amino acids. 20 different amino acids, each have particular r group thus giving them varied chemical properties. This is the reason why proteins can carry out different functions. 3-d orientation + amino acid sequence leads to varying chemical properties. Proteins perform complex functions due to high chemical complexity. Enzymes catalyze particular chemical reactions by bind to subspecific area. Most cellular functions are performed by proteins. Motors move along scaffolds to transport materials within the cells. Receptors allow for communication between inside and outside of cells. Mutation in dynamin gene sequence change in dynamin protein (now slightly unstable as high temperature unfolds) neuron communication requires dynamin. Lower temperature leads to restoration of synaptic connection. Model organisms allow rapid identification of gene functions relevant for mammalian biology hippo gene in fruit flies is a common gene used for suppression of tissue growth.
