Which element is found in all living cells on Earth?
carbon
Give two statements that describe a benefit of using scientific names to identify a species.
Scientific names are not used interchangeably among similar species.
Scientific names help scientists understand how different species are related.
Scientific names must fit a particular set of rules before they can be assigned.
The best indicator of an organism’s evolutionary fitness is the number of
offspring it produces that survive to reproductive age
In 1997, scientists in the United Kingdom announced the birth of Dolly, a female sheep, the world’s first mammal to be successfully cloned. Unlike naturally conceived offspring, cloned organisms share identical DNA sequences with their “parent,” the animal from which the DNA was obtained.
Why does Dolly’s “parent” have to be a female?
They have the EXACT same genes.
Oxygen in Earth’s early atmosphere was generated by marine organisms such as cyanobacteria, which are sometimes called blue-green algae.
By what process did cyanobacteria oxygenate the atmosphere?
photosynthesis
Which two most derived groups of plants share the most recent common ancestor?
ginko and wheat
or
ginko and spruce
Researchers studying hummingbirds in the Andes Mountains of Ecuador made several observations:
There are many species of hummingbirds.
The species are not separated by any physical barriers.
Unique hummingbird species are found at different elevations in the Andes.
What hypothesis about the different elevations can be made based on these observations?
Conditions at each elevation favor different hummingbird traits.
What can we conclude about the sheep gametes based on the following karyotype?
The gametes have 27 chromosomes
or
The sheep is male
What structures are in eukaryotic cells but NOT in prokaryotic cells?
a nucleus and other membrane-bound organelles
About 200 years ago, the population of Antarctic fur seals (Arctocephalus gazella) on islands near Antarctica was estimated between 160,000 and 180,000 individual seals. When explorers discovered the islands, they began intensive hunting of the seals for their fur, and stopped only when there were no more seals left to hunt. Around 50 years ago, scientists discovered and protected a small colony of 25 seals, and began recording the size of the population over time. Their data are shown in the graph.
Which year did the fur seal population begin to recover from intensive hunting?
year 13
(or any number between 10-20)
Scientists have recently reclassified two populations of organisms that were originally classified as the same species. They are now classified as two unique species because of genetic differences that have been observed between the two populations. One of these populations lives on the mainland and the other lives on a nearby island. Both populations live in forest habitats and have similar diets.
Which factor most likely resulted in the observed genetic differences of these two populations?
The geographic isolation of the island prevented gene flow between the two populations.
A substitution mutation occurs in an original segment of DNA and causes a change in the amino acid chain produced.
Original: Met-Ala-Lys-Cys
Mutant: Met-Ala-Thr-Cys
What is the codon for the amino acid that was substituted?
ACA
or
ACG
A student fills a beaker with a 5% salt solution. The student places a dialysis bag containing a 15% salt solution into the beaker. Then the student measures the salinity of the salt solution in the beaker after 5 minutes. The dialysis tubing is permeable to salt and water.
What is the movement of water AND the movement of salt?
water in
salt out
Populations of lake sturgeon fish are declining in the Ohio River due to dam construction, water pollution, and over-harvesting. Scientists propose a plan to reintroduce a population of lake sturgeon into the Ohio River. The map shows the distribution of lake sturgeon populations included in the study.
Which population would experience reproductive isolation?
Sturgeon River
Warblers are small insect-eating birds common to North America. Several closely related species of warblers evolved approximately two million years ago during the period between the advance and retreat of large glaciers.
How did this glacial activity lead to the formation of these species?
Glacial ice separated and isolated warbler sub-populations.
How can different types of cells found in the same plant perform different functions?
They have different sets of genes that are active.
The graph shows enzyme activity at different temperatures. Describe why this graph looks this way.
If the temperature is too cold or too hot, the enzyme will not work properly.
The graph shows the diversity of marine invertebrates over the last 300 million years. Three time periods are marked in the graph.
In which time period would volcanic eruptions have significantly reduced the amount of dissolved oxygen in the oceans?
Time 2
Scientists and doctors have observed that many species of bacteria are no longer susceptible to antibiotics that were once effective.
Why are some bacteria species are no longer susceptible to certain antibiotics?
The bacteria that survived the antibiotics passed that resistance to future generations.
Sponges are marine organisms that can reproduce both sexually and asexually. Gel electrophoresis was used to analyze the DNA of six sponges (A–F) that share a common parent. The gel electrophoresis results are shown.
Which of the sponges that were most likely produced by asexual reproduction?
A, C, E