106k views
2 votes
PLEASE HELP

1. Giraffes use their extremely long necks to reach the leaves high up on acacia trees, which other animals cannot reach, giving them a food source for which they have few competitors. What can you conclude about natural selection from this observation?

a) Giraffe necks get longer over a lifetime of stretching, and their offspring inherit the longer necks of their parents.
b) All giraffes are born with short necks and, eating acacia leaves causes them to stretch over a lifetime.
c) Other animals will mimic the giraffe and grow longer necks.
d) The giraffes with the longest necks survive and produce offspring.

2. Based on fossilized evidence, there are scientific claims made about the evolution of certain species. If a scientist studying the fossils of a specific species had a hypothesis other than what was currently accepted, what steps should be taken to have the alternative hypothesis considered?


a) Since the original hypothesis is untestable given the circumstances, another one is more likely to be correct.
b) If an alternative hypothesis sounds plausible it could be used in place of the original hypothesis.
c) The scientist should publish the alternative hypothesis in a popular magazine to gain public support.
d) It is useful to test alternative hypotheses and know that they are incorrect.

3. Darwin noticed differences in the beak shapes of finches on the various islands of the Galapagos and surmised that they all might have evolved from a common ancestor on the mainland. If Darwin had known about molecular biology, a field of study that did not exist at the time he lived, how might he have used it to test his hypothesis?

a) He could have done DNA tests on the birds to see how closely they were related.
b) He could have checked to see if they shared similar cellular structures indicating their common ancestry.
c) He could have used modern tools to make more accurate measurements of beak shape and size.
d) He could have genetically engineered finches with extreme beak shapes to see how they survived.

4. The insulin used to treat people with diabetes is commonly produced by inserting the DNA sequence for human insulin into a bacterium. The insulin the bacterium produces using that sequence is then harvested. In fact, DNA sequences from virtually any living organism could be inserted into a bacterium and the bacterium would be able to use the sequences to make the same proteins that the original organism did. In what way does this provide evidence for evolution?

a) Since bacteria are able to use DNA from other organisms, they must have evolved from them as a common descendant.
b) Bacteria must be less evolved than higher organisms since they can still make proteins from the DNA of other organisms.
c) Since the genetic code is the same across species, these species must have inherited it from a common ancestor.
d) Since foreign DNA was added to the bacteria, it evolved beyond higher organisms.

5. Which of the following is the best example of evolution occurring? (2 points)

a) Some of the trees in places with harsh winters lose their leaves in the fall.
b) Strains of bacteria can become immune to antibiotics that once killed them effectively.
c) Viruses can attack single-celled organisms as well as multicellular organisms.
d) Lions and cows both have hair covering their bodies and give birth to live offspring.

6. Coral snakes are brightly colored highly venomous snakes with red, yellow, and black bands along their bodies. Another species of snake, called the scarlet king snake, has similar bands of red, black, and yellow. Which of the following describes the conditions that resulted in a large population of king snakes with these types of markings?

a) King snakes and coral snakes relied on similar food sources that contributed to their unique coloring.
b) Since king snakes with these markings were avoided by predators, they were able to survive to pass on this trait to offspring.
c) Coral snakes mated with king snakes often enough to produce another species of king snake with the red, black, and yellow.
d) Overproduction of offspring increased the likelihood that the genetic mutation leading to these bands would spontaneously occur.

1 Answer

3 votes
The correct options are as follows:
1. D.
Natural selection refers to the process by which living organisms that are more adapted to their environments usually survive and produce offspring that are like them. In the case of giraffes, the giraffes with the longest necks were able to survive in their environment and they reproduce offspring that are like them.
2. D
In the scientific world, scientists have open minds and they welcome all new ideas. These new ideas have to be tested to ensure that they are correct and superior to the facts that are already known. When a new hypothesis is put forward by a scientist, many scientists all over the world will test the hypothesis is order t confirm if it correct. If the hypothesis is found to be correct it will be accepted by all scientists.
3. A.
DNA test is a laboratory analysis that can be used to assess the level of relationship between living organisms. Related living organisms usually have some similar genes in their DNA, the level of closeness of these organisms will determine the quantity of similar genes that will be found in their DNA. Unrelated organisms on the other hand will have little or no similar genes in their DNA.
4. C.
The genetic code is the same across species, this fact points to the possibility that all living organisms originated from common ancestors. This support the evolution theory which stated that all living organisms descended from a common ancestor.
5. B.
Antibiotic drugs are usually effective against bacteria and other microbes, but the microbes can evolve and develop resistance to these drugs. Microbes are considered to have evolved when drugs that are used to inactivate them before no longer have any effect on them, thus they can easily survive in the presence of the drugs.
6. B.
If a particular specie of animal is able to avoid predators, it will increase in number more that those that are prey on by predators. The kings snakes were probably able to avoid predators, that is why, they were able to survive, reproduce offspring and increase in population in that particular ecosystem.
User Hans Koch
by
7.8k points