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Extra Question Chapter 1:Chemical Reaction And Equations

Extra Question II Chapter 1:Chemical Reaction And Equations

Extra Question Chapter 2:Acid Ans Base

Important Question Chapter 3:Metal and Non Metal

Chapter 4:Carbon And Its Compoundl

Chapter 5:Periodic Classification of elememt

Chapter 6:Life Processes

Chapter 7:Control and coordination

Chapter 8:How Do Organisms Reproduce?

Chapter 9:Hearedity And Evolution

Chapter 10:Light Reflection and Refraction

Chapter 11:The Human Eye and Colorful World

Chapter 12:Electricity

Chapter 13:Magnetic effect of electric current

Chapter 14:Sources of energy

Chapter 15:Our Environment

Extra Questions – Heredity and Evolution – CBSE Class 10 Science

Question 1

What is heredity?

Answer

Heredity refers to the transmission of traits from parents to their offspring either through asexual reproduction or sexual reproduction. The offspring cells and organisms acquire the genetic information of their parent cell or organisms

Question 2

Define evolution.

Answer

Evolution is the gradual development of organisms from a simple to a more complex form over several generations. It explains the diversity and unity of life on earth.

Question 3

What are genes?

Answer

Genes are units of heredity which are transferred from parents to offspring and determine some characteristics of the offspring. They are segments of DNA and are responsible for the physical and inheritable characteristics or traits of an individual.

Question 4

What is a trait?

Answer

A trait is a distinct characteristic or quality of an organism that can be inherited or acquired. Traits include physical characteristics such as height, eye color, and behavioral characteristics such as the ability to sing.

Question 5

What is variation?

Answer

Variation refers to the differences in traits among the individuals of the same species. Variation can be caused by genetic differences, environment, or a combination of both.

Question 6

Explain the term 'natural selection'.

Answer

Natural selection is a process by which species adapt to their environment. It involves survival of the fittest, where organisms best adapted to their environment are more likely to survive and pass on their traits to the next generation.

Question 7

What is speciation?

Answer

Speciation is the formation of new and distinct species in the course of evolution. It occurs when populations of a species become isolated and evolve differently.

Question 8

What is the role of DNA copying in inheritance?

Answer

DNA copying plays a crucial role in inheritance as it helps in the transmission of traits from parents to offspring. The process of DNA copying brings about a variation each time cell division occurs, which forms the basis of evolution.

Question 9

Define fossils and explain their significance.

Answer

Fossils are preserved remains or traces of animals, plants, and other organisms from the remote past. They provide direct evidence about the life forms and their chronology on earth. They also provide evidence about how evolution has occurred.

Question 10

Explain Mendel's experiment with peas.

Answer

Gregor Mendel conducted breeding experiments with pea plants. He took into consideration various contrasting traits like height, seed color, flower color, etc. He observed that some traits were dominant over others, and these findings led him to formulate the laws of inheritance.

Question 11

What is genetic drift?.

Answer

Genetic drift is a mechanism of evolution that involves random changes to the gene pool of a small population, which can lead to significant changes in the genetic makeup of the population over time..

Question 12

What is the significance of sex in reproduction?

Answer

Sexual reproduction leads to greater genetic diversity as genes from two parents combine in unique ways in each offspring. This genetic variation can lead to better survival of the species in changing environments.

Question 13

What is a chromosome?

Answer

A chromosome is a long DNA molecule with part or all of the genetic material of an organism. Humans have 23 pairs of chromosomes.

Question 14

What is meant by acquired traits and inherited traits?

Answer

Acquired traits are the ones that an organism develops during its lifetime, like learning a skill. These traits cannot be passed on to the next generation. Inherited traits are those that are passed from parents to offspring through genes, like eye color or skin color

Question 15

What is the difference between dominant and recessive traits?

Answer

Dominant traits are those that are expressed even if only one copy of the gene for that trait is present. Recessive traits are those that are expressed only when two copies of the gene for that trait are present.

Question 16

What are homologous and analogous organs? Give examples

Answer

Homologous organs are those with similar structure and origin but different functions, like the forelimbs of humans and wings of birds. Analogous organs have different structures and origins but similar functions, like the wings of a bird and wings of a butterfly. .

Question 17

What is the evolutionary significance of the human appendix?

Answer

The human appendix is considered a vestigial organ, with no apparent function in humans. Its presence suggests that our evolutionary ancestors may have had a diet that required a large cecum, which is used in the digestion of plant material. Over time, as human diets changed, the appendix became less useful.

Question 18

Explain how genetic variation is advantageous to the survival of a species.

Answer

Genetic variation is advantageous because it allows a population to adapt to changing environments. If an environment changes, and some individuals have a trait that allows them to survive and reproduce, they will pass on their genes to the next generation. Over time, these genes become more common in the population, leading to evolution.

Question 19

What does the term 'fitness' mean in the context of evolution?

Answer

In the context of evolution, fitness refers to an organism's ability to survive and reproduce in its environment. The more offspring an organism leaves in the next generation, the fitter it is considered.

Question 20

How can the age of fossils be determined?

Answer

The age of fossils can be determined using several methods. One common method is relative dating, which involves looking at the layers of rock in which the fossil was found. Fossils in lower layers are older than those in upper layers. Another method is radiometric dating, which measures the decay of radioactive elements within the fossil or the rocks associated with it. This method can provide a more precise age.