Tag: botany

Questions Related to botany

Mutations are responsible for.

botany classical genetics variation and its type natural selection introduction to genetics

  1. Extinction of organisms

  2. Variations in population

  3. Increase in population

  4. Maintaining genetic continuity

Show answer
Correct Option: B
Explanation:
Mutations are changes in the DNA. A single mutation can have a large effect, but in many cases, evolutionary change is based on the accumulation of many mutations. Gene flow is any movement of genes from one population to another and is an important source of genetic variation.

So, the correct answer is 'Variations in population'.

Recombinations and variations in eucaryotic organisms are due to

botany classical genetics variation and its type natural selection introduction to genetics

  1. Mitosis and meiosis

  2. Fertilization and mitosis

  3. Meiosis and fertilisation

  4. Meiosis and amitosis

Show answer
Correct Option: C
Explanation:

The process of forming new allelic combination in offspring by exchanges between genetic materials of parents is called Recombination.

Variation is a change or slight difference in condition, amount, or level, typically within certain limits appear in the progeny compared with parents.

Recombination and variations appear in sexually reproducing organisms during meiosis and fertilization.

So, the correct option is ‘Meiosis and fertilization’.

Some individuals produce lesser amounts of insulin. It is a type of

botany classical genetics variation and its type natural selection introduction to genetics

  1. Physiological variation

  2. Behavioural variation

  3. Morphological variation

  4. All the above

Show answer
Correct Option: A
Explanation:
  • Physiological variation is related to the differences in the ways individuals of the same species react to conditions in their environment because of difference in their functioning of the body. Production of insulin is an example of physiological variation.
  • So, the correct option is 'Physiological variation'


Mutation, selection and genetic drift are three important forces which are responsible for evolutionary changes

botany classical genetics variation and its type natural selection introduction to genetics

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Evolution is dependent on the natural selection , genetic drift , gene flow , mutation are the main factors responsible for evolution .

Hence the given statement is true

Aspects such as sedentary habit, territoriality, etc., not aiding diversification are classified as 

botany classical genetics variation and its type natural selection introduction to genetics

  1. Reproductive isolation

  2. Mutational effects

  3. Biological barriers

  4. Genetic incompatibility

Show answer
Correct Option: C
Explanation:
Biological barriers are factors that prevent species migration, interbreeding, or free movement. What determines the barrier depends on the species and it's method of movement. For some species biological barriers are sedentary habits, physical like bodies of water, mountains, or deserts.
Mutation effects is the formation of altered protein from an altered or mutated genes.
When the species are not able to cross breed is called as genetic incompatibility
Thus, the correct answer is option C.

Which one of the following traits of the parents cannot be inherited by their children?

botany classical genetics variation and its type natural selection introduction to genetics

  1. Cleft chin

  2. Snub nose

  3. Scarred eyebrow

  4. Brown eyes

Show answer
Correct Option: C
Explanation:

Scarred eyebrow is an acquired trait which is never passed on to the offspring because scarring does not change the genes of the reproductive cells of the parent.

Which of the following statements is correct?

botany classical genetics variation and its type natural selection introduction to genetics

  1. Accumulation of useful mutations through ages has led to the creation of new species of living beings.

  2. Genetic variability provides raw material for the operation of natural selection and reproductive isolation.

  3. Genetic variability is produced by gene mutations.

  4. All of the above.

Show answer
Correct Option: D
Explanation:

Genetic variability is the change in the sequence of the gens due to mutations. These mutations has led to new species generation. The so evolved species are selected in the environment based on natural selection

Laboratory mice are to be classified based on genes A, B, and C, none of  these are lethal genes. How many would be genetically different gametes if they are formed by genotype AaBbCc?

botany classical genetics variation and its type natural selection introduction to genetics

  1. $3$

  2. $6$

  3. $8$

  4. $9$

  5. $12$

Show answer
Correct Option: C

Ultimate source of variation is

botany classical genetics variation and its type natural selection introduction to genetics

  1. Fertilization

  2. Mitosis

  3. Meiosis

  4. Mutations

Show answer
Correct Option: D
Explanation:

Variation is a change or slight difference in condition, amount, or level, typically within certain limits appear in the progeny compared with parents. Variations appear in sexually reproducing organisms during meiosis and fertilization and also by mutations. So, the correct option is ‘Mutation’.

The ultimate source of continuous variations is 

botany classical genetics variation and its type natural selection introduction to genetics

  1. Natural selection

  2. Sexual reproduction

  3. Hormonal action

  4. Mutations

Show answer
Correct Option: B
Explanation:

Sexual reproduction involves gamete formation and fertilisation. During fertilisation, 1 gamete from each parent combines to form a zygote. Because of recombination and independent assortment in meiosis, each gamete contains a different set of DNA. This produces a unique combination of genes in the resulting zygote and ultimately within the organism.

As reproduction takes place continuously throughout the generation as well as these variations are inheritable, it is the ultimate source of continuous variations.
So, the correct option is 'Sexual reproduction.'