Tag: darwin's theory of evolution

Questions Related to darwin's theory of evolution

Which of the following differences between Lamarckism and Darwinism is incorrect?

  1. It does not consider struggle for existence, Struggle for existence is very important in this theory

  2. Only useful variations are transferred to the next generation, All the acquired characters are inherited to the next generation

  3. Neglect survival of fittest, Based on survival of the fittest

  4. None of these


Correct Option: B
Explanation:

According to Lamarckism, all the acquired characters are inherited to the next generations. According to Darwinism only useful variation are transferred to the next generation.

So, the correct answer is 'only useful variations are transferred to the next generation, All the acquired characters are inherited to the next generation'

Which of the following explained evolution in most acceptable form?

  1. Lamarck, Darwin, Hugo de Vries

  2. Anaximander, Darwin, Malthus

  3. F. Redi, Richter, Cuvier

  4. Lamarck, Hardy Weinberg, Darwin


Correct Option: A

Which of the following facts develop suspicions in Lamarckism?

  1. Human females are not born with bored ear pinna although they have been bored for thousand of years.

  2. Giraffe has long neck to eat leaves of tall trees.

  3. A stag can run fast to protect against the enemies.

  4. None of the above


Correct Option: A
Explanation:

Lamarckism was disproved later after putting up the human ear piercing example. Lamarckism which is otherwise called as use and disuse theory advocated the idea that animals acquired characteristics after using certain physical traits constantly.

During a conversation at the dinner table, a high school student tells his mother that, "At first all giraffes had short necks because they all ate leaves close to the ground, but when all those leaves were gone some giraffes started being born with long necks".
Which statement would be most helpful for the student to understand the concept?

  1. Phenotypic variations occur through random mutations which are then selected for or against.

  2. The phenotype for neck length changed in giraffes so that the species did not go extinct.

  3. Short-necked giraffes developed long necks in response to increased competition for food.

  4. When the environment changed, the struggle to exist created new mutations in the gene pool and natural selection acted on them.


Correct Option: D
Explanation:

For the giraffes, the change in the position of the food  (leaves) from near to ground level to higher on the trees, triggered for adaptation to prevent extinction. So, those giraffes that underwent genetic changes/variations and developed long necks were able to obtain food and survive in the changed environmental conditions, while others perished, as this change in the genetic pool was beneficial for the giraffes propagation. It was passed on to next generation and so the modern day giraffe has long necks.

The phenotypic determination by genetic variation in a population refers to the degree of

  1. Fitness

  2. Heritability

  3. Limited environmental resources

  4. Overproduction of offspring

  5. Phenotypic variation


Correct Option: B
Explanation:

The observed phenotypic variations of a trait in a population which is caused by genetic variation are called as heritability. It shows the extent to which a trait is determined genetically. Fitness refers to the ability of survival and production of fertile offspring. Limited environmental resources lead to the struggle for existence, not phenotypic variations. Overproduction of offspring represents the biotic potential of species.  

Therefore, the correct answer is option B.

In order to increase its population through natural selection, an allele should have one of the following features.

  1. Individuals with the allele are better able to find food.

  2. Individuals with the allele are better able to resist disease.

  3. Individuals with the allele have an increased ability to find and retain mates.

  4. Individuals with the allele produce more offspring that reach adulthood.

  5. Individuals with the allele have a longer lifespan than those without it.


Correct Option: D
Explanation:

A trait is favored by natural selection when it imparts reproductive fitness to the population. Reproductive fitness refers to ability of organisms to pass traits to offspring. This makes option D correct as individual with allele that enable it to produce fertile and viable offspring is favored by natural selection. 

The present giraffe has a long neck as compared to its ancestors. Lamarck believed it could be due to

  1. Natural selection

  2. Isolation

  3. Inheritance of acquired characters

  4. Speciation


Correct Option: C

Who first placed fossils in chronological series in evolutionary context?

  1. Leonardo da Vinci

  2. Lamarck

  3. Cuvier

  4. Darwin


Correct Option: B
Explanation:

The first theory of evolution was proposed by Jean Baptiste de Lamarck. Lamarckism proposed:

  • Some internal forces are present in all organisms. By the presence of these forces, the organism has the tendency to increase the size of their organs or the entire body.
  • Environment influences all type of organisms. Changing environment give rise to new needs. New needs or desires produce new structure and change habits of the organism.
  • If an organ is constantly used, it would be better developed whereas disuse of organ results in its degeneration.

So, the correct option is 'Lamarck'.

Key point of Lamarck's view about organic evolution is that every offspring 

  1. Is similar to its parent.

  2. Inherits characters acquired by the parental generation.

  3. Shows struggle for existence.

  4. Repeats phylogeny in its ontogeny.


Correct Option: B
Explanation:
According to Lamarck's theory of inheritance of acquired characters, the skills or morphological changes acquired by an organism during its lifetime will be passed on to the next generation.
So, the correct answer is'Inherits characters acquired by the parental generation'

Lamrck's theory of evolution fails to explain 

  1. Indian women have been getting their ears pierced for thousands of years, but not a single baby with pierced ears is born.

  2. Giraffes have long necks because they have to eat leaves from the tall trees on their habitat.

  3. Deer have the capacity to escape from agile enemies because these can run very fast.

  4. High attitude pines have branches which slope down so that snow fails to collect them in winter.


Correct Option: A
Explanation:

Indian women have getting their ears pierced for thousands of years, but this character does not passed to any offspring, this casts doubt on lamarck's theory of evolution. Later on, in Neo-lamarckism it was explained that only those characters will be inherited which can affect germ cells, while characters that affect somatic cells do not pass to descendants. Thus, the correct answer is 'Indian women have been getting their ears pierced for thousands of years, but not a single baby with pierced ears is born.'