Genomes
Only about 1.5% of the human genome codes for proteins. What makes up the majority of the remaining "non-coding" portion?
a) Introns and repetitive DNA
b) Ribosomes
c) Empty space
d) vital protein-encoding genes
a) Introns and repetitive DNA
Domain Bacteria and Domain Archaea are more evolutionary similar than Archaea and Eukarya.
True or False
False
Which enzyme is essential for a retrotransposon to integrate into a new genomic location?
a) DNA Polymerase III
b) Reverse Transcriptase
c) RNA Primase
d) Transcriptase
b) Reverse Transcriptase
This is the process in which individuals with favorable inherited traits are more likely to survive and reproduce
How many SI Sessions have we had (including this one)?
3
Why do prokaryotic genomes typically lack the vast "repetitive DNA" sequences and introns found in eukaryotes?
Small gene size, higher gene density, absence of introns, and efficient organization all reduce the presence of noncoding DNA and increase the presence of coding DNA.
Which type of evidence for evolution is represented by the similarity in mammalian forelimbs?
a) Analogous structures
b) Homologous structures
c) Vestigial structures
d) Random chance
b) Homologous structures
Which scientist provided the first evidence that genetic elements are not stationary within the genome?
Barbara McClintock
Bacteria evolve to become resistant to antibiotics
True or False
False
What is a transitional fossil? Give an example.
A fossil showing traits of both an ancestral group and its descendants
ex. Archaeopteryx links dinosaurs and birds
A genome with extremely high gene density (e.g., 900 genes/Mb) is most likely to belong to:
a) A unicellular bacterium
b) A multicellular fungus
c) A complex mammal
a) A unicellular bacterium
Contrast Lamarck’s "Inheritance of Acquired Characteristics" with Darwin’s "Natural Selection" regarding how a trait is passed to offspring
Lamarck hypothesized that an organism could change its body through "use and disuse." If an organ or body part was used extensively, it would grow or strengthen; if it was not used, it would deteriorate.
Darwin proposed natural selection that individuals born with favorable heritable traits are more likely to survive and reproduce, leading to an increased frequency of those specific traits in the next generation. (CHANGES IN POPULATION OVER SEVERAL GENERATIONS)
These collections of two or more identical or very similar genes, such as the human globin genes, are common in eukaryotic genomes
Multigene families
In a population, natural selection acts directly on the __________, which then changes the __________ of the population.
a) Genotype / Phenotype
b) Individual / Ecosystem
c) Phenotype / Allele Frequency
d) Genotype / Variety
c) Phenotype / Allele Frequency
How many pairs of chromosomes do humans have? How many pairs of chromosomes do chimpanzees have?
Humans have 23 pairs of chromosomes
Chimpanzees have 24 pairs of chromosomes
Which of the following is correct about homeotic genes?
a. They control the size of your genome
b. They control the development of body parts
c. They control your gene density
d. They control your ability to adapt to the environment
b. They control the development of body parts
Sugar gliders are marsupial mammals native to Australia, while flying squirrels are placental mammals native to North America. Both species possess thin, fleshy membranes that allow them to glide between trees, yet they are not closely related.
Explain why the gliding membrane is considered an analogous structure rather than a homologous one.
They are analogous structures because they evolved independently as similar solutions to similar environmental challenges, rather than being inherited from a common ancestor
Changes in these types of DNA sequences can contribute to genome evolution by increasing or decreasing the production of specific proteins.
Regulatory Sequences
Based on Darwin’s observations and the evolution of drug-resistant bacteria like MRSA, which statement about Natural Selection is true?
a) Natural selection creates new beneficial traits, such as antibiotic resistance, specifically when an organism is exposed to a new environment.
b) Individuals evolve new inherited characteristics during their lifetime to ensure they can produce more offspring than their environment can support.
c) Natural selection acts by selecting for favorable heritable traits already present in the population, increasing their frequency over generations.
D) Evolution only occurs over millions of years and cannot be observed in species with short generation times like Staphylococcus aureus
c) Natural selection acts by selecting for favorable heritable traits already present in the population, increasing their frequency over generations.
How many days did it take for E. coli to develop resistance against antibiotics? How did it develop resistance so quickly? List two reasons.
11 days, short germination times and high mutation rates allowed for evolution by natural selection to occur rapidly.
Describe the relationship between genome size and gene density as you move from Bacteria to complex Eukaryotes.
Inverse relationship between genome size and gene density.
Prokaryotes have a small gene size and a high gene density. Eukaryotes have a large gene size and a low gene density.
Name the four specific types of scientific data that document the pattern of evolution
Direct Observations
Homology
Fossil Records
Biogeography
Charles Darwin based his theory of natural selection on two key observations regarding populations and their environments. Identify these two observations and explain the inferences he drew from them.
Observation #1: Individuals within a population often vary in their inherited traits.
Inference #1: Individuals with traits that provide a higher probability of surviving and reproducing tend to leave more offspring than others.
Observation #2: All species are capable of producing more offspring than the environment can support; consequently, many of these offspring fail to survive.
Inference #2: This "unequal ability" to survive and reproduce leads to the gradual accumulation of favorable traits in the population over many generations
Darwin observed that mushrooms produce spore clouds that contain billions of spores every day. Which of Darwin's observations does this align with? Describe the associated inference.
Provide the number and description.
Observation 2, All species produce more offspring than the environment can support and many of these organisms fail to survive and reproduce.
Inference 2, This unequal ability of individuals to survive and reproduce will lead to the accumulation of favorable traits in the population over generations
What does MRSA stand for. In the context of evolutionary biology, describe the role MRSA plays in documenting the pattern of evolution.
Methicillin-resistant S. aureus
Demonstrated the evolution of drug-resistant bacteria.