DNA and the Molecular Structure of Chromosomes
The genetic material must replicate, control the growth and development of the organism, and allow the
organism to adapt to changes in the environment.
Genotypic Function: Replication
Structure in Prokaryotes and
The DNA molecules of prokaryotes and viruses
are organized into negatively
2. Prokaryotes are monoploid and are part
of the nucleoids (only have 1 set of
3. Most viruses and
Topoisomerases: are enzymes that regulate the overwinding or underwinding of DNA.
chromosome can thus
occur after a lambda
the duplex state.
junction where the
Bidirectional Replication: The Phage
MULTIPLE DNA POLYMERASES AND PROOFREADING
1. DNA polymerases are processive enzymes that catalyze the covalent extension at the
3 termini of growing polynucleotide chains. All polymerases require
preexisting DNA with two essential components, one providin
Centrosomes, Microtubules, and Centrioles: Centrosome duplicates (S phase): Centrosomes move to
opposite sides of nucleus during prophase. Mitotic spindle apparatus assembles microtubules(MT).
MicroTubule Organizing Centers (MTOCs).
Spindle MTs make conta
CHAPTER 10. Replication of DNA and Chromosomes
Basic Features of DNA Replication In Vivo
DNA replication occurs semiconservatively, is initiated at
unique origins, and usually proceeds bidirectionally from eac
Population genetics studies genes in groups of individual.
It focuses on
1. Allelic variation among individuals
2. Transmission of allelic variants from parents to offspring generation after generation
3. Temporal changes
Variation in Nucleotide Sequences
DNA sequencing can be used to study genetic variation. Ex: study of sequence variability in the gene for alcohol
dehydrogenase, Adh, in Drosophila melanogaster.
Techniques for Detecting Nucleotide Polymorphisms
A. The Forked-Line Method for an
two or more genes
Tri-hybrid heterozygous cross .
-monohybrid crossDd x Dd.Ratio
The Forked-Line Method for a Testcross
is used to determine if a group exhibiting a
dominant trait is hom
Many eukaryotic cells
possess two copies of each
chromosome - diploid
state; is characteristic of
the cells in the body of a
eukaryote that is, the somatic cells.
contrast, the sex cells or gametes usually possess only
of each chro
INITIATION OF DNA CHAINS WITH RNA PRIMERS
RNA Primers are Used to Initiate DNA Synthesis
Each new DNA chain is initiated by a short RNA primer synthesized by DNA primase. RNA-DNA
hybrid: DNA primase s a short RNA primer. The enzyme DNA primase catalyzes t
3.ESTIMATING ALLELE FREQUENCIES
Blood types are determined by two alleles of a gene on chromosome 4: LM, which produces the M blood type, and
LN, which produces the N blood type (see Chapter 4). People who are LMLN heterozygotes have the MN blood
The compaction level of interphase chromosomes is not completely uniform
Less condensed regions of chromosomes
Regions where 30 nm fiber forms radial loop domains
Tightly compacted regions of chromoso
Testing Genetic Hypotheses
Hypothesis: a well-formulated scientific idea
Data collected from observations or from experimentation enable scientists to test hypotheses.
Genetics: Are the results of a cross consistent with a hypothesis?
The Chi-S quare T
1. The presence of _ suggests the _ of Hardy-Weinberg equilibrium.
Which information do we need to predict the allelic frequencies after one round of
selection in a given population?
selection coefficients for each genotype/allelic frequ
1. Migration constitutes an important evolutionary force because it _ allelic frequencies
across generations, eventually leading to the _ of the population.
2. The main consequences of genetic drift are _.
1. Mutations are difficult to study because _.
they are often rare and have subtle effects.
2. Organisms displaying different phenotypes at different environment are example of _.
3. There are _ kinds of variation among
1. According to The fundamental Principal of Phylogenetic inference:
Synapomorphies identify monophyletic groups
2. In phylogenetic inference, a preexisting (or ancestral) character is referred to as _.
3. In evolutionary trees,
1. _ constitute _ for those cases where evolutionary hypotheses _
tested by using _.
- observational evolutionary studies/ alternatives/ cannot be/ laboratory
2. We define _ as the _ change in _ across a range of _.
DNA replication & the Central Dogma
19 Sep 2016
1. Quiz-quiz #2 (8:00-8:18)
2. Class activity reviewed (8:20-8:25)
3. Why care about DNA replication? (just
a couple of minutes)
4. Content (8:27-8:50)
Class activity: Make your own DNA
Why care about
1. The concept of natural selection was describe at least by _ different authors
before its revision by _.
2/ Darwin and A.R. Wallace
2. What is the most important conclusion from Darwins book On the Origin of
Earths organisms are
When is natural selection going to reach perfection?
Why does the US Supreme Court strikes down the teaching of creation
science and intelligent design in schools?
because they are against the first amendment
1. Why does evolution matters?
- Because it addresses matters of life and death.
2. HIVs evolution is.
- shortsighted because it does not look for the future of the host (it kills the
3. The HIV protein that is involved in attachment of th
1. The Theory of Descent with Modification predict that a regions extant plants and
animals will be most similar to fossils
- form the same region
2. Transitional forms are.
- species showing a mix of features between ancestral populations and l
1. Darwin proved Lamarck wrong because .
- Darwin revealed that the length of the neck in giraffes is not the result of the
inheritance of acquired characteristics
2. Evolution constitutes a scientific
3. The neutral
In both prokaryotic and eukaryotic cells, the genetic material is organized into chromosomes.
Eukaryotic: 22 plus one (X or Y), non-circular, linear. Mitochondrial DNA is circular and from
Prokaryotic: 1, circu
3 Milestones of Genetics:
1) G.Mendel: genes and the rules of inheritance.
2) J.Watson and F.Krick: the structure of DNA
3) The Human Genome Project: sequencing DNA and cataloguing genes. (a worldwide effort
to determine the sequence o
Mendelism: The Basic Principles of Inheritance
1. Mendel did experiments on garden pees: Pisum Sativum. Pea flowers contain
both male (anthers: pr
Genetics Study Guide
Single cell, do not have nucleus. Includes
eubacteria & archaea.
Prokaryotes do not have organelles but
have some proteins
Small diameter with small amounts of
Usually circular DNA molecule
Histones- proteins that DNA tightly coils around to form chromosomes, making it able to fit
in the nucleus.
Cytoskeleton- a microscopic network of protein filaments and tubules in the cytoplasm of
many living cells, giving them shape and coherence.