Tag: selection and evolution

Questions Related to selection and evolution

Which of the following relies on molecular biology methods to provide evidence for demonstrating relationships among species? 

  1. Analysis of habitats to determine if differences in habitat could lead to speciation

  2. Analysis of embryonic structures such as gill arches to determine evolutionary relationships

  3. Analysis of vertebrate skeletons to determine common structures

  4. Analysis of cytochrome C proteins in various species

  5. Analysis of relationships between predators and prey to determine if coevolution occurs


Correct Option: D
Explanation:
Molecular biology methods relies on biochemical evidences for depicting common ancestry. For example, cytochrome C. It is a respiratory pigment found in all eukaryotic cells, which is a part of electron transport system. Cytochrome-C accepts hydrogen ions in all eukaryotic cells. The cytochrome-C molecule of human and chimpanzee is identical whereas Neurospora differ from human's cytochrome-C by the position of 44/104 amino acid.
So, the correct answer is 'Analysis of cytochrome C proteins in various species'.

When originally classified, whales and hippopotamuses were placed into different orders. Molecular analysis recently suggested that whales (order Cetacea) and hippopotamuses (order Artiodactyla) are extremely closely related, sharing a recent common ancestor.
This has led some taxonomists to create a new phylogenetic tree that puts the two orders together into a single clade. It is still unclear as to whether the whales diverged from Hippopotamuses before or after the divergence of other species in the order Artiodactyla.
An interesting physical feature of whales is the presence of vestigial pelvic bones.
If scientists determine that whales diverged from the artiodactyl order after llamas and giraffes, what should be true of the vestigial pelvic bones of whales?

  1. They are a shared ancestral feature of whales, llamas, and giraffes.

  2. They are a shared derived feature of whales, llamas, and giraffes.

  3. They are a shared ancestral feature of whales.

  4. They are a shared derived feature of whales.


Correct Option: D
Explanation:
The presence of vestigial pelvic bones is a characteristic of whales, even though pelvic bone was present in the species that diverged Hippopotamuses. It was not used in whales and hence vestigial. The bone being vestigial is characteristic of whales
So, the correct answer is 'They are a shared derived feature of whales'

The difference between Homo sapiens and the Homo erectus was _______________ .

  1. Homo sapiens originated in Africa while Homo erectus was in Asia

  2. Homo erectus were much smaller in size than homo sapiens

  3. Homo erectus stayed in Africa while Homo sapiens did not

  4. The size of their brain of Homo eructus was smaller to homo sapiens


Correct Option: D
Read the passage and answer the following question.
Some dinosaur bones were discovered fairly recently that still contained significant amounts of the protein collagen in a non-fossilized form. Enough material was available to determine its amino-acid sequence. This allowed researchers to compare its sequence with the sequences of collagen from currently existing animals. 
Identify the organisms that are closely resemble to the dinosaur sequence?
  1. Birds

  2. Lizards

  3. Amphibians

  4. Rodents

  5. Fish


Correct Option: A
Explanation:

Scientists working across a variety of disciplines have discovered evidence of common descent among the living organisms on earth.  This evidence which constructs a theoretical framework on which evolutionary theory rests demonstrates the natural processes  of earth's biodiversity. These studies are based on fossil studies and comparison of the DNA genetic sequences thereby revealing phylogenetically closer organisms. A protein is a chain of amino acids and the functional end-product of a gene. Studies by evolutionary scientists involve the comparative analysis of both DNA and protein sequences and comparing the same type of gene or protein sequence between organisms helps to determine the closeness of a relation.  According to their studies, two organisms are considered closely related if they share a high percentage of amino acid sequence similarity for a certain protein. The recent studies however, bring to light the close resemblance of Birds to the extinct dinosaur. Thus, the correct answer is option A.

A human species who were more intelligent than the present human beings

  1. Ramapethicus

  2. Australopithicusafricanus

  3. Homo erectus

  4. Homo fossilis


Correct Option: D

Read the passage and answer the following question.
Cytochrome-c is a protein that scientists often use to compare the evolutionary relationships among species. There is one difference in the cytochrome-c sequence between humans and rhesus monkeys. There are ten differences between human and kangaroos.
What can infer about the relationship between these species?

  1. Humans and kangaroos have the same proteins coded in their genes

  2. Humans and kangaroos share a more recent ancestor than humans and rhesus monkeys

  3. Humans are not closely related to either kangaroos or rhesus monkeys.

  4. Humans and rhesus monkeys share a more recent ancestor than humans and kangaroos

  5. Rhesus monkeys and kangaroos share a more recent ancestor than humans and rhesus monkeys.


Correct Option: D
Explanation:
The rhesus monkey and humans have the most similar amino acids in the haemoglobin protein. This shows that they share a more recent common ancestor than the other organisms do.

Appearance of teeth in the embryo of a bird proves that 

  1. Ontogeny repeats phylogeny

  2. Evolution has taken place

  3. Birds have evolved from reptiles

  4. All the above


Correct Option: A
Explanation:

Even though birds lost teeth as physical structures between 60 and 80 million years ago, several studies have shown that those tissues within birds that would normally produce teeth still retain the potential to do so. For example, in 1821, Geoffrey St. Hilaire was the first scientist to publish the observation that some bird embryos exhibited evidence of tooth formation, but his contemporaries considered his work flawed.  

So, the correct answer is  "Ontogeny repeats phylogeny".

Which of the following is sequenced during study of phylogeny?

  1. mRNA

  2. rRNA

  3. tRNA.

  4. DNA


Correct Option: B
Explanation:
Ribosomal RNA groupings contrast between species, because of change. Through variety in r RNA groupings, we can recognize living beings on around the species level and follow developmental connections.
So, the correct option is 'r RNA'.

Which of the following is correct?

  1. 99% of existed species are extinct.

  2. 25% of existed species are extinct.

  3. 40% of existed species are extinct.

  4. 30% of existed species are extinct.


Correct Option: A
Explanation:

Around 99% of all species which amounts to over 5 billion species which ever lived on Earth are said to be extinct. The current number of species present on Earth is estimated to be 10-14 million. Hence option A is correct.

Which of the following is included in those species which are likely to become extinct?

  1. Endangered species

  2. Critically endangered species

  3. Vulnerable species

  4. All of the above


Correct Option: D
Explanation:

The species (including animals, plants, fungi, etc.) which are vulnerable to endangerment in the near future are known as threatened species. The International Union for Conservation of Nature (IUCN) is the authority on threatened species, and it treats threatened species as a group of three categories, depending on the degree relative to which they are threatened. Those categories are Vulnerable species; Endangered species and Critically endangered species. 

So, the correct answer is 'All of the above'.