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Consider the following statements about "Mass Extinction" 1. Mass extinction refers to when the Earth loses more than three-quarters of its species in a geologically short period of time. 2. So far, during the entire history of the Earth, there have been four mass extinctions, and we are experiencing the sixth mass extinction. Which of the above statements is/are incorrect?

Consider the following statements about "Mass Extinction" 1. Mass extinction refers to when the Earth loses more than three-quarters of its species in a geologically short period of time. 2. So far, during the entire history of the Earth, there have been four mass extinctions, and we are experiencing the sixth mass extinction. Which of the above statements is/are incorrect? Correct Answer 2 only

The correct answer is 2 only.

In News

  • The ongoing sixth mass extinction may be one of the most serious environmental threats to the persistence of civilization, according to new research.
  • The research was published in the journal Proceedings of the National Academy of Sciences of the United States of America (PNAS).

Key Points

  • What is the mass extinction of species?
    • Mass extinction refers to a substantial increase in the degree of extinction or when the Earth loses more than three-quarters of its species in a geologically short period of time. Hence, Statement 1 is correct.
    • So far, during the entire history of the Earth, there have been five mass extinctions. Hence, Statement 2 is NOT correct.

Additional Information 

  • What is the sixth mass extinction?
    • The sixth, which is ongoing, is referred to as the Anthropocene extinction.
    • Researchers have described it as the “most serious environmental problem” since the loss of species will be permanent.
  • Why it is attributable to humans?
    • One of the reasons that humanity is an “unprecedented threat” to many living organisms is because of their growing numbers.
    • The loss of species has been occurring since human ancestors developed agriculture over 11,000 years ago. Since then, the human population has increased from about 1 million to 7.7 billion.

Related Questions

Choose the sentences which can be S2 and S3. S1: Extinction of a particular animal or plant species occurs when there are no more individuals of that species alive anywhere in the world - the species has died out. S2: S3: S4: Today human intervention is causing rapid extinction of animals. P. For example, a mass extinction caused the death of many different types of animals and plants, including the dinosaurs. Q. Sometimes extinctions happen at a much faster rate than usual. R. This is a natural part of evolution.
Read the passage carefully and choose the best answer to each question out of the four alternatives and click the button corresponding to it.
Ants have been living on the earth for more than 100 million years and can be found almost anywhere on the planet. It is estimated that there are about 20000 different species of ants. For this reason ants have been called Earth's most successful species. If you watch ants for any length of time you will see that they really do communicate with each other and very effectively too. Ants communicate by touching each other with their antennae. Ants also use chemicals called pheromones to leave scent trails for other ants to follow. Ants build many different types of homes. Many ants build simple little mounds out of dirt or sand. Other ants use small sticks mixed with dirt and sand to make a stronger mound that offers protection from rain. Western Harvester ants make a small mound on top, but then tunnels up to 15 feet straight down to hibernate during winter. Ant mounds consist of many chambers connected by tunnels. Different chambers are used for nurseries, food storage, and resting places for the worker ants. Some ants live in wood like termites. Army ants don't make a home at all but travel in a large groups searching for food. Ants are social insects which means they live in large colonies or groups. Some colonies consist of millions of ants. There are three types of ants in each species, the queen, the sterile female workers and males. The male ants only serve one purpose, to mate with future queen ants and do not live very long. The queen grows to adulthood, mates, and then spends rest of her life laying eggs. A colony may have only one queen, or there may be many queens depending on the species. Ants go through four stages of development: egg, larva, pupa and adult.
Why are ants called the 'Earth's' most successful species?
Read the passage carefully and choose the best answer to each question out of the four alternatives and click the button corresponding to it.
Ants have been living on the earth for more than 100 million years and can be found almost anywhere on the planet. It is estimated that there are about 20000 different species of ants. For this reason ants have been called Earth's most successful species. If you watch ants for any length of time you will see that they really do communicate with each other and very effectively too. Ants communicate by touching each other with their antennae. Ants also use chemicals called pheromones to leave scent trails for other ants to follow. Ants build many different types of homes. Many ants build simple little mounds out of dirt or sand. Other ants use small sticks mixed with dirt and sand to make a stronger mound that offers protection from rain. Western Harvester ants make a small mound on top, but then tunnels up to 15 feet straight down to hibernate during winter. Ant mounds consist of many chambers connected by tunnels. Different chambers are used for nurseries, food storage, and resting places for the worker ants. Some ants live in wood like termites. Army ants don't make a home at all but travel in a large groups searching for food. Ants are social insects which means they live in large colonies or groups. Some colonies consist of millions of ants. There are three types of ants in each species, the queen, the sterile female workers and males. The male ants only serve one purpose, to mate with future queen ants and do not live very long. The queen grows to adulthood, mates, and then spends rest of her life laying eggs. A colony may have only one queen, or there may be many queens depending on the species. Ants go through four stages of development: egg, larva, pupa and adult. Antennae are used by ants to
Read the passage carefully and choose the best answer to each question out of the four alternatives and click the button corresponding to it.
Ants have been living on the earth for more than 100 million years and can be found almost anywhere on the planet. It is estimated that there are about 20000 different species of ants. For this reason ants have been called Earth's most successful species. If you watch ants for any length of time you will see that they really do communicate with each other and very effectively too. Ants communicate by touching each other with their antennae. Ants also use chemicals called pheromones to leave scent trails for other ants to follow. Ants build many different types of homes. Many ants build simple little mounds out of dirt or sand. Other ants use small sticks mixed with dirt and sand to make a stronger mound that offers protection from rain. Western Harvester ants make a small mound on top, but then tunnels up to 15 feet straight down to hibernate during winter. Ant mounds consist of many chambers connected by tunnels. Different chambers are used for nurseries, food storage, and resting places for the worker ants. Some ants live in wood like termites. Army ants don't make a home at all but travel in a large groups searching for food. Ants are social insects which means they live in large colonies or groups. Some colonies consist of millions of ants. There are three types of ants in each species, the queen, the sterile female workers and males. The male ants only serve one purpose, to mate with future queen ants and do not live very long. The queen grows to adulthood, mates, and then spends rest of her life laying eggs. A colony may have only one queen, or there may be many queens depending on the species. Ants go through four stages of development: egg, larva, pupa and adult. What does the Western Harvester do in winter ?
Read the passage carefully and choose the best answer to each question out of the four alternatives and click the button corresponding to it.
Ants have been living on the earth for more than 100 million years and can be found almost anywhere on the planet. It is estimated that there are about 20000 different species of ants. For this reason ants have been called Earth's most successful species. If you watch ants for any length of time you will see that they really do communicate with each other and very effectively too. Ants communicate by touching each other with their antennae. Ants also use chemicals called pheromones to leave scent trails for other ants to follow. Ants build many different types of homes. Many ants build simple little mounds out of dirt or sand. Other ants use small sticks mixed with dirt and sand to make a stronger mound that offers protection from rain. Western Harvester ants make a small mound on top, but then tunnels up to 15 feet straight down to hibernate during winter. Ant mounds consist of many chambers connected by tunnels. Different chambers are used for nurseries, food storage, and resting places for the worker ants. Some ants live in wood like termites. Army ants don't make a home at all but travel in a large groups searching for food. Ants are social insects which means they live in large colonies or groups. Some colonies consist of millions of ants. There are three types of ants in each species, the queen, the sterile female workers and males. The male ants only serve one purpose, to mate with future queen ants and do not live very long. The queen grows to adulthood, mates, and then spends rest of her life laying eggs. A colony may have only one queen, or there may be many queens depending on the species. Ants go through four stages of development: egg, larva, pupa and adult. What kind of homes do the army of ants build ?
Read the passage carefully and choose the best answer to each question out of the four alternatives and click the button corresponding to it.
Ants have been living on the earth for more than 100 million years and can be found almost anywhere on the planet. It is estimated that there are about 20000 different species of ants. For this reason ants have been called Earth's most successful species. If you watch ants for any length of time you will see that they really do communicate with each other and very effectively too. Ants communicate by touching each other with their antennae. Ants also use chemicals called pheromones to leave scent trails for other ants to follow. Ants build many different types of homes. Many ants build simple little mounds out of dirt or sand. Other ants use small sticks mixed with dirt and sand to make a stronger mound that offers protection from rain. Western Harvester ants make a small mound on top, but then tunnels up to 15 feet straight down to hibernate during winter. Ant mounds consist of many chambers connected by tunnels. Different chambers are used for nurseries, food storage, and resting places for the worker ants. Some ants live in wood like termites. Army ants don't make a home at all but travel in a large groups searching for food. Ants are social insects which means they live in large colonies or groups. Some colonies consist of millions of ants. There are three types of ants in each species, the queen, the sterile female workers and males. The male ants only serve one purpose, to mate with future queen ants and do not live very long. The queen grows to adulthood, mates, and then spends rest of her life laying eggs. A colony may have only one queen, or there may be many queens depending on the species. Ants go through four stages of development: egg, larva, pupa and adult. What is the purpose of male ants ?
Which one of the following is the correct sequence of various stages of operating cycle of a manufacturing company?  1. Raw material conversion period, work-in-progress conversion period, Finished goods conversion period, Receivables conversion period 2. Raw material conversion period, work-in-progress conversion period, Creditors payment period, Receivables conversion period 3. Creditor payment period. Raw material conversion period, Receivables conversion period, work-in- progress conversion period 4. Raw material conversion period, Finished goods conversion period, work-in- progress conversion period. Receivables conversion period 
The conditions regarding selection from a list of suitable candidates to be called for interview after a written examination for appointment of management-level persons to a multi-national company providing accounting services and sales are mentioned below. Candidates: a) Must have a Bachelor's degree in Basic Science with 65% or more marks or BE with 55% or more marks. b) Must have passed the examination with 70% or more marks. c) Age must be between 25 to 30 years as of 1/4/18. d) Must have 3 years of experience in an Accounting Institution and must have a Diploma in Accounting with 60% or more marks. e) Must be currently getting CTC of Rs. 6 lakh or more per annum. If the candidate: 1) If he fulfills all the other conditions other than A above, he will be designated as Junior Accountant. 2) If he fulfills all the other conditions other than (d) and (e) above, he can be designated as Trainee-Accountant. If he fulfills all the above conditions including 5 years of experience, he can be designated as a Senior Accountant. He can be designated as Manager (Accounts) if he fulfills all the above criteria including educational qualifications of CA/ ICWA/ MBA (Finance). Study all the above information and answer the following question. Varun has passed the CA exam and has a bachelor's degree in basic science and a diploma in accountancy, having scored 75% or more in the written examination during his entire career and also in the written examination. His age is 27 years and with 4 years of experience in Accountancy, he has a CTC salary of 18 lakhs per annum. To which of the following positions can he be referred? Select from the given options.
Read the passage carefully and select the best answer to each question out of the given four alternatives.
What is Gandhian philosophy? It is the religious and social ideas adopted and developed by Gandhi, first during his period in South Africa from 1893 to 1914, and later of course in India. These ideas have been further developed by later "Gandhians", most notably, in India by, Vinoba Bhave and Jayaprakash Narayan. Outside of India some of the work of, for example, Martin Luther King Jr. can also be viewed in this light. Understanding the universe to be an organic whole, the philosophy exists on several planes - the spiritual or religious, moral, political, economic, social, individual and collective. The spiritual or religious element, and God, is at its core. Human nature is regarded as fundamentally virtuous. All individuals are believed to be capable of high moral development, and of reform. The twin cardinal principles of Gandhi's thought are truth and nonviolence. It should be remembered that the English word "truth" is an imperfect translation of the Sanskrit, "satya", and "non-violence", an even more imperfect translation of "ahimsa". Derived from "sat" - "that which exists" - "satya" contains a dimension of meaning not usually associated by English speakers with the word "truth". There are other variations, too, which we need not go into here. For Gandhi, truth is the relative truth of truthfulness in word and deed, and the absolute truth - the Ultimate Reality. This ultimate truth is God (as God is also Truth) and morality - the moral laws and code - its basis. Ahimsa, far from meaning mere peacefulness or the absence of overt violence, is understood by Gandhi to denote active love - the pole opposite of violence, or "Himsa", in every sense. The ultimate station Gandhi assigns non violence stems from two main points. First, if according to the Divine Reality all life is one, then all violence committed towards another is violence towards oneself, towards the collective, whole self, and thus "self"-destructive and counter to the universal law of life, which is love. Second, Gandhi believed that ahimsa is the most powerful force in existence. Had himsa been superior to ahimsa, humankind would long ago have succeeded in destroying itself. The human race certainly could not have progressed as far as it has, even if universal justice remains far off the horizon. From both viewpoints, non violence or love is regarded as the highest law of humankind.
According to Gandhiji, truth complies to which of the following?
Read the passage carefully and select the best answer to each question out of the given four alternatives.
What is Gandhian philosophy? It is the religious and social ideas adopted and developed by Gandhi, first during his period in South Africa from 1893 to 1914, and later of course in India. These ideas have been further developed by later "Gandhians", most notably, in India by, Vinoba Bhave and Jayaprakash Narayan. Outside of India some of the work of, for example, Martin Luther King Jr. can also be viewed in this light. Understanding the universe to be an organic whole, the philosophy exists on several planes - the spiritual or religious, moral, political, economic, social, individual and collective. The spiritual or religious element, and God, is at its core. Human nature is regarded as fundamentally virtuous. All individuals are believed to be capable of high moral development, and of reform. The twin cardinal principles of Gandhi's thought are truth and nonviolence. It should be remembered that the English word "truth" is an imperfect translation of the Sanskrit, "satya", and "non-violence", an even more imperfect translation of "ahimsa". Derived from "sat" - "that which exists" - "satya" contains a dimension of meaning not usually associated by English speakers with the word "truth". There are other variations, too, which we need not go into here. For Gandhi, truth is the relative truth of truthfulness in word and deed, and the absolute truth - the Ultimate Reality. This ultimate truth is God (as God is also Truth) and morality - the moral laws and code - its basis. Ahimsa, far from meaning mere peacefulness or the absence of overt violence, is understood by Gandhi to denote active love - the pole opposite of violence, or "Himsa", in every sense. The ultimate station Gandhi assigns non violence stems from two main points. First, if according to the Divine Reality all life is one, then all violence committed towards another is violence towards oneself, towards the collective, whole self, and thus "self"-destructive and counter to the universal law of life, which is love. Second, Gandhi believed that ahimsa is the most powerful force in existence. Had himsa been superior to ahimsa, humankind would long ago have succeeded in destroying itself. The human race certainly could not have progressed as far as it has, even if universal justice remains far off the horizon. From both viewpoints, non violence or love is regarded as the highest law of humankind.
According to the passage, which of the following statement is not true?