Genetic Variations

Q.

What is the importance of evolution?

Q.

What is the modern synthetic theory of evolution?

Q. The variations which are non-inheritable and disappear with the death of an individual are___________.

1. Germinal variations
2. Somatic variations
3. Gene pool
4. Genetic variations

Q.

What factors affect genetic variation?

Q. Write two points of difference between asexual and sexual types of reproduction. Describe why variations are observed in the offspring formed by sexual reproduction?

Q.

All of the following are sexual sources of genetic variation except

1. Random fertilization

2. Mutation

3. Crossing-over

4. Production of offspring from two parents

Q. Select a statement that is not true with respect to variation.

1. All variations in a species have equal chance of survival.
2. Change in the genetic composition results in variation.
3. Selection of variants by environmental factors form the basis of evolutionary process.
4. Variation is minimum in asexual reproduction.

Q. Which type of ear lobe is dominant character -

1. Both
2. Attached
3. None of these
4. Free

Q. Question 41
Reproduction is linked to the stability of the population of a species. Justify the statement.

Q.

With the help of an example, explain how variation leads to evolution.

Q.

What is variation? Give an example.

Q.

Asexual mode of reproduction leads to more variation in the offspring as compared to sexual mode of reproduction.

1. True

2. False

Q.

Name one variation in humans connected with ears.

Q.

Why are asexually reproducing organisms more capable of showing the hereditary features?

Q.

Characters that are transmitted parents to offspring during reproduction show

1. Only similarities with parents

2. Only variation with parents

3. Both similarities and variations with parents

4. Neither similarities nor variations

Q. Environmental factors can influence variation.

1. True
2. False

Q.

Question 34
Give two reasons for the appearance of variations among the progeny formed by sexual reproduction.

Q. Question 15
Which of the following statements is not true with respect to variation?

(a) All variations in a species have equal chance of survival.
(b) Change in genetic composition results in variation.
(c) Selection of variants by environmental factors forms the basis of evolutionary processes.
(d) Variation is minimum in asexual reproduction.

Q. Variations are _________ in the offsprings of Amoeba.

1. More
2. Less
3. Definite
4. Scanty

Q. What is an organic evolution? It cannot be equated with progress. Explain with the help of a suitable example.

Q.

(a) What do you understand by the term 'variation ' ?

(b) Name two human traits which show variation.

(c) How does the creation of variation in a species ensure its survival ?

Q.

Question 15
Which of the following statements is not true with respect to variation?

(a) All variations in a species have an equal chance of survival.
(b) Change in genetic composition results in variation.
(c) Selection of variants by environmental factors forms the basis of evolutionary processes.
(d) Variation is minimum in asexual reproduction.

Q. Give the respective terms used for studying:
1:The mechanism by which variations are created and inherited
2:The development of new type of organisms from the existing ones

Q. Statement 1: In the process of evolution, one species always gets lost to give rise to new species.

Statement 2: The newly generated species are always better than the existing previous ones.

Statement 3: Natural selection and genetic drift leads to speciation.

1. Only statement 2 is correct.
2. Only statement 3 is correct.
3. All the statements are correct.
4. Only statement 1 is correct.

Q.

One example of variation observed in human beings is presence of ____ and___ ear lobe.

Q. The two types of variations are:

1. Somatic and Asomatic
2. Asomatic and Genetic
3. Somatic and Germinal
4. Germinal and Genetic

Q.

Question 1
Why are human beings who look so different from each other in terms of size, colour and looks said to belong to the same species?

Q. Reason of diversity in living being is:

A. Mutation
B. Long term evolutionary change
C. Gradual change
D. Short term evolutionary change

[1 mark]

Q.

How does evolution affect us today?

Q.

A sugarcane field consist of little variations when compared to butterfly population. The reason could be

1. Sugarcanes grow in more watery conditions

2. Sugarcanes grow and multiply by vegetative reproduction

3. Sugarcanes have more adventitious roots

4. Sugarcanes have fibrous root systems