Kerala SSLC Biology Chapter 8 Questions The Paths Traversed by Life English Medium
Question 1.
The theory argues that life has originated in some other planet in the universe and accidentally reached the earth.
a. Natural selection
b. Chemical evolution
c. Panspermia
d. Mutation theory
Answer:
c. Panspermia
Question 2.
The chemical evolution theory was put forward by
a. Urey – Miller
b. Oparin – Halden
c. Watson – Crick
d. Hugo de Vries
Answer:
b. Oparin – Halden
Question 3.
The islands in which Charles Darwin conducted his study.
a. Galapagos
b. Indonesia
c. Japan
d. Sri Lanka
Answer:
a. Galapagos
Question 4.
Most primitive member of human race.
a. Ardipithecus ramidus
b. Homo habilis
c. Homo erectus
d. Homo sapiens
Answer: .
a. Ardipithecus ramidus
Question 5.
Fill up the blanks by observing the relationship – between the first pair.
a. Darwin: Natural selection
Hugo de Vries: ……………………….
b. Gibbon: Hominoidea
Gorilla: ……………………….
c. Contemporary to modern man: Homo neanderthalensis
Modern man:……………………….
Answer:
a. Mutation
b.Hominoidea
c. Homo sapiens
Question 6.
Find the odd one out, note down the common features of others.
a. Homo habilis, Orangutan, Homo sapiens, Ardipithecus ramidus
b. Gibbon, Monkey, Gorilla, Chimpanzee
c. Hydrogen, Nitrogen, Oxygen, Carbon dioxide
Answer:
a. Orangutan, others are members of human evolution.
b. Monkey, others are members of Hominoidea.
c. Oxygen, others are gases present on primitive earth.
Question 7.
The names of organisms that are included in the evolutionary history of modern man are given in the box. Select the answer from the box related to the statements given below.
Homo neanderthalensis, Homo erectus,
Ardipithecus ramidus, Homo sapiens,
Homo habilis
a. Modern man
b. Most primitive member of the human race.
c. Made weapons from stones and bone pieces.
d. Contemporary to modern man.
e. Have the ability to stand erect, thick chin and large teeth.
Answer:
a. Homo sapiens
b. Ardipithecus ramidus
c. Homo habilis
d. Homo neanderthalensis
e. Homo erectus
Question 8.
Some situations that helped in the origin of life existed in primitive earth. Select the situation from the following.
a. There was no water in primitive earth.
b. There was no free oxygen in primitive earth.
c. There were no gases in primitive earth.
d. There was availability of energy in primitive. earth.
Answer:
b. There was no free oxygen in primitive earth, d. There was availability of energy in primitive earth.
Question 9.
Read the description on bacteria and answer the questions given below.
Under favourable circumstances, bacteria divide every 20 minutes. The rapid multiplication results in the mutation in the DNA. Mutation causes the formation of new bacteria, producing different enzymes.
a. What will be the crisis created in the medical field by such changes in pathogenic bacteria?
b. Which theory of evolution is justified by changes in bacteria?
Answer:
a. Bacteria which show immunity to medicines are formed.
b. The theory of Natural Selection.
Question 10.
The main ideas related to an argument attempted to explain the history of evolution is given below.
- The characters developed during the lifetime of organisms are called acquired characters.
- The accumulation of acquired characters led to the formation of new species.
a. Name the scientist who put forward these ideas?
b. This argument was not accepted by the . scientific world. Why?
Answer:
a. Jean Baptist Lamarck.
b. The acquired characters were not inheritable.
Question 11.
Description of Darwin’s theory is given below. Which is the wrong statement?
a. Competition between organisms for the limited resources is known as struggle for existence.
b. Organisms with favourable variations survive.
c. The structure of organisms formed by continuous use is transmitted to next generations.
d. Organisms with unfavourable variations get eliminated.
Answer:
c. The structure of organisms formed by continuous use is transmitted to next generations.
Question 12.
What are the evidences given by biochemistry and physiology for evolution?
Answer:
Enzymes control chemical reactions in all organisms. Energy is stored in ATP molecules. Genes determine hereditary traits. Carbohydrates, proteins and fats are the basic substances. It is clear from these facts that different species that exist today have a common ancestor.
Question 13.
Arrange column B in accordance with column A.
| A | B |
| Ardipithecus ramidus | Modern man. |
| Homo erectus | Slender body. |
| Homo sapiens | Most primitive member of the human race. |
| Have the ability to stand erect. |
Answer:
| A | B |
| Ardipithecus ramidus | Most primitive member of the human race. |
| Homo erectus | Have the ability to stand erect. |
| Homo sapiens | Modem man. |
Question 14.
What are homologous organs? Write the evidences given by these for evolution?
Answer:
Organs that are similar in structure and perform different functions are called homologous organs. Such anatomical resemblances justify the inferences that all organisms evolved from a common ancestor.
Question 15.
Given below are the criticisms raised against – Darwin’s theory of Natural Selection.
a. Lack of experimental support.
b. Does not explain how variations within species are transmitted to the next generation.
What explanation will you give to this in the background of the advancement of genetics?
Answer:
a. Molecular biology, Mutation, etc.
b. Explanations from Neo Darwinism, Mutation, Crossing over.
Question 16.
Create an evolutionary tree of Anthropoidea by using the words given in the box.
Monkey, Gorilla, Gibbon, Cercopithecoidea, Orangutan, Man, Hominoidea, Chimpanzee.
Answer:
Question 17.
Write two examples for the theories discussed among the scientists in connection with the origin of life.
Answer:
The theory of chemical evolution, The panspermia theory.
Question 18.
What are fossils? What are the inferences you can arrive at from fossil studies?
Answer:
- Fossils are the remnants of primitive organisms. The inferences that we can arrive at from such studies.
- Primitive fossils have simple structure.
- Recently formed fossils have complex structure.
- Certain fossils are connecting links between different species.
Question 19.
Gibbon, Baboons, Oranguttan, Gorilla. Find the odd one. In which group the other organisms belong? Write the characteristics of this group.
Answer:
Baboons Gibbon, Oranguttan, Gorilla belong to the Hominoidea group.
The characteristics of Hominoidea are developed brain, freely movable hands.
Question 20.
Dinesh applied DDT, a pesticide in his garden to control termites. He could control termites successfully during the initial stages, but subsequent usage of the same did not produce any results. Evaluate the survival of termites on the basis of Natural Selection.
Answer:
According to The Theory of natural selection, the organisms are in competition for limited resources (struggle for existence). Only organisms with favourable variations survive. And this leads to the evolution of new species with favourable variations. They become accustomed to the new environment.
This new species produce more number of offsprings (overproduction).
Here the pests have variations to overcome the DDT. Organisms with favourable variations survive and lead to the evolution of new species which can survive DDT.
Question 21.
Write your inference by analyzing the following information in connection with evolution.
Difference from the amino acids in the beta chain of haemoglobin in man.
Chimpanzee: Nil
Gorilla: difference of one amino acid Rat: difference of 31 amino acids
a. Substantiate the reason for variations of amino acids of protein like haemoglobin in above organisms.
b. Write the advantage of the micro-level knowledge of protein and genes of related organism.
Answer:
a. Mutation
b. Through a comparative study of protein molecules in different species, the evolutionary relationship among organisms can be identified.
This is an effective method to draw the evolution showing the branching of organisms from a common ancestor.
22. Tabulate the data appropriately in the box given below:
i. Chemical evolution
ii. Natural selection
iii. Panspermia theory
iv. Mutation theory
| Origin of Life | Evolution |
| ………………………….
…………………………. |
…………………………
………………………….
|
Answer:
| Origin of Life | Evolution |
| Chemical evolution | Natural selection |
| Panspermia theory | Mutation theory |
Question 23.
“The coñstant use of antibiotics develops resistance in bacteria” Substantiate the above statement on the basis of the theory of natural selection.
Answer:
- Presence of antibiotics in body.
- Bacteria capable of and incapable of resisting antibiotics
- Those that are capable of resisting antibiotics will exist.
- Resistant bacteria produce more offspring.
Question 24.
Scientific study of the remnants, body parts. and imprints of primitive organisms are evidences on evolution.
a. What inferences do we arrive at, through such scientific studies?
b. How will you explain these inferences as evidences on evolution?
Answer:
a.
- Primitive fossils have simple structure.
- Recently formed fossils have complex structure.
- Certain fossils are connecting links between different species.
b.
- Organisms with complex structure are formed from those with simple structure.
- Certain fossils indicate the evolution of one species from another species.
Question 25.
A few concepts of scientists like Darwin and Malthus are given below. Classify them in the table given below.
a. Selection by nature leads to the diversity of species.
b. Rate of food production does not increase proportionately to the increase in population.
c. Those organisms that ovèrcome the unfavourable situations will survive.
d. Scarcity of food and starvation lead to struggle for existence.
| Concepts of Darwin | Concepts of Matthus |
| ……………………………
…………………………… |
……………………………
…………………………… |
Answer:
Concepts of Darwin
a. Selection by nature leads to the diversity of species.
c. Those organisms that overcome the unfavourable situations will survive.
Concepts of Matthus
b. Rate of food production does not increase proportionately to the increase in population.
d. Scarcity of food and starvation lead to struggle for existence.
Question 26.
An excerpt from the science article ‘Man and Evolution’ is given below. Analyse the excerpt and answer the questions.
Certain evolutionary features that make man different from other animals are included in evolutionary history. This helped him in his dominance over nature and other organisms. His interferences had created a negative impact on the existence of other organisms.
a. What are the features that make man different from other animals?
b. Has man’s interference led to Biodiversity deterioration as mentioned in the excerpt? Evaluate.
Answer:
a. High cranial capacity, ability to stand erect, ability to walk on two legs, ability to make and use machines and tools, cultural development.
b. Yes. Climate changes, deteriorating habitats, extinction.
Kerala SSLC Biology Chapter Wise Questions and Answers