Biology

Genetics and Evolutionary Biology

1,156 Questions

Genetics and evolutionary biology explain how traits are passed from parents to offspring and how species change over time. Key concepts include genetic drift, inbreeding, and heredity. This topic is fundamental for the biology section of many competitive tests.

Heredity and traitsGenetic variations and driftInbreeding conceptsEvolutionary mechanisms

Genetics and Evolutionary Biology Questions

Multiple choice commercial studies biotechnology: general introduction introduction to genetic engineering and production of insulin use of efficient and eco-friendly technology genetics of the future

____ results in change in genetic makeup of organisms.

  1. Genetic appliance

  2. Genetic diversity

  3. Genetic engineering

  4. All of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Genetic engineering, also called as genetic modification, is the direct manipulation of an organism's genome using biotechnology. It is a set of technologies used to change the genetic makeup of cells, including the transfer of genes within and across species boundaries to produce improved or novel organisms. 

Multiple choice botany breeding and biotechnology branches of biotechnology gene cloning biotechnology and genetic engineering

Which of the following bacteria are used in study of 'genetics'?

  1. E. coli

  2. Bacillus

  3. Pseudomonas

  4. Rhizobium
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
E. coli is the most well-understood bacterium and is an extremely important model organism in many fields of research, particularly molecular biology, genetics, and biochemistry. It is easy to grow under laboratory conditions, and research strains are very safe to work with. As with many bacteria, E. coli grows quickly, which allows many generations to be studied in a short time. Under ideal conditions, E. coli cells can double in number after only 20 minutes. The genetics of E. coli are well-understood and can be readily manipulated.
Therefore, the correct answer is option A.
Multiple choice botany modes of reproduction why do plants reproduce? reproduction and variation the life cycle of plants

Read the following statements about reproduction and select the incorrect one.

  1. It is a biological process in which an organism gives rise to young ones

  2. It enables the continuity of the species

  3. It produces genetic variations in organisms

  4. It maintains populations of the young and adult persons only
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • Reproduction is a biological process in which an organism gives rise to young ones. It is a fundamental feature of all known life. Reproduction enables the continuity of the species and produces genetic variations in organisms. 
  • Reproduction not only maintains populations of the young and adult persons but also that of older adults.
  • Reproduction is a key process that determines the distribution of people of various ages in a population, called age structure.
  • So the correct option is D.
Multiple choice botany modes of reproduction why do plants reproduce? reproduction and variation the life cycle of plants

Offspring formed as a result of sexual reproduction exhibit more variations because

  1. Sexual reproduction is a lengthy process.

  2. Genetic material comes from two parents of the same species.

  3. Genetic material comes from two parents of different species.

  4. Genetic material comes from many parents.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Offspring formed as a result of sexual reproduction exhibit more variations because genetic material comes from two parents of the same species.

In asexual reproduction, the offspring that are produced are not only identical to the parent but are also exact copies of their parent. It is because in asexual reproduction, there is the involvement of a single parent. So, in this case the genetic variation is not created.
While in sexual reproduction, genetic variation is created and inherited. In sexual reproduction, two parents having different genetic composition participate in the reproductive process and also involve fusion of male and female gametes, which gives rise to the new individual having genetic composition of both.

Multiple choice botany modes of reproduction why do plants reproduce? reproduction and variation the life cycle of plants

Only variations that confer an advantage to an individual organism will survive in a population. 

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
All the variations do not have an equal chance of surviving in the environment in which they find themselves. The chances of surviving depend on the nature of variations. Different individual would have different kind of advantages. A bacteria that can withstand heat will survive better in a heat wave. Selection of variants by environmental factors forms the basis for revolutionary process.
Multiple choice botany classical genetics incomplete dominance deviation from mendelism inheritance

Complete dominance does not occur in

  1. Mirabilis jalapa

  2. Oenothera lamarckiana

  3. Lathyrus odoratus

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

As we know that trait is represented by two contrasting factors of a gene in a heterozygous individual; the allele/factor that can express itself in the heterozygous individual is called as the dominant trait. The other factor, whose effect is masked by the presence of dominant factor, is called recessive factor. In the case of complete dominance, the heterozygous individual shows dominant phenotype. Law of incomplete dominance tells that where none of the factors of a gene is dominant, the phenotype of the heterozygous dominant individual is the blend of dominant and recessive traits. For example, flower colour in Mirabilis jalapa and sweet peas (Lathyrus odoratus) shows incomplete dominance and the monohybrid cross between two pure varieties gives 1:2:1 phenotypic ratio in F$ _2$ generation which is 3:1 in dominant traits. Monohybrid cross in Oenothera lamarckiana does not give typical 3:1 ratio, hence does not follow complete dominance. Pisum sativum was the experimental plant of Mendel and show complete dominance. 

Multiple choice zoology why classification? history of classification of organisms introduction to classification of living organisms living world and classification

Species is

  1. Population of individuals having same genotypes and

    phenotypes

  2. A group of individuals inhabiting a geographical area

  3. A group of interbreeding populations

  4. Population of one type
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Species are the groups of individuals that sexually interbreed or are potentially interbreeding form.

Multiple choice zoology molecular basis of inheritance genome projects human genome project human genome project and dna fingerprinting

The sequencing of the entire genome (the totality of all genes) of an organism was completed in 1996. The organism was

  1. Human being

  2. Yeast

  3. Albino mouse

  4. Plasmodium vivax
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The sequencing of the entire genome of an organism was completed in 1996 and the organism was yeast.

So, the correct option is 'Yeast'.

Multiple choice zoology the paths traversed by life mutational theory of evolution theories of evolution other theories of evolution

The tendency of a large population to remain in genetic equilibrium can n be disturbed by

  1. Presence of random mating

  2. Lack of gene migration

  3. Lack of mutations

  4. Presence of selective mating
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
For a population to be in Hardy-Weinberg equilibrium five conditions must be met :
1. Population must be very large.
2. Population must be isolated from other populations (no immigration or emigration).
3. No mutations
4. Random mating
5. No natural selection
Non-random/selective/assortative mating causes more expression of recessive phenotypes.
So, the correct option is 'Presence of selective mating'.
Multiple choice zoology the paths traversed by life mutational theory of evolution theories of evolution other theories of evolution

In a random mating population in equilibrium, which of the following brings about a change in a gene frequency in a non-directional manner?

  1. Mutation

  2. Random drift

  3. Selection

  4. Migration
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In a random mating population in equilibrium, mutations bring about a change in gene frequency. Mutations are non-directional.

Hugo de Vries conducting experiments on Evening Primrose and when he self-pollinated the plants from F1 generation. He found that though the majority of plants are similar to parents, there were a few different plants which appeared at random, in which inherited characters appeared suddenly without any previous indication in the race.
On this basis, he gave the mutation theory
  • mutations appear suddenly but become operational immediately
  • mutations are inheritable
  • do not revolve around normal characteristics of species
  • same type of mutations can appear in the number of individuals of the species

Multiple choice zoology the paths traversed by life mutational theory of evolution theories of evolution other theories of evolution

The concept of sudden genetic change which breeds true in a species is represented as 

  1. Inheritance of acquired characters

  2. Natural selection

  3. Laws of inheritence

  4. Mutation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The concept of sudden genetic change which breeds true in a species is represented as a mutation. Any sudden or spontaneous change in character which is inheritable is known as mutation. It is defined as the changing of the structure of a gene, resulting in a variant form which may be transmitted to subsequent generations, caused by the alteration of single base units in DNA, or the deletion, insertion, or rearrangement of larger sections of genes or chromosomes. 

So, the correct answer is option D.

Multiple choice zoology the paths traversed by life mutational theory of evolution theories of evolution other theories of evolution

Gene frequency in a population remains stable, unless and until there is ___________.

  1. Random drift

  2. Random mating

  3. Selection

  4. Mutation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • In biology, a mutation is the alteration of the nucleotide sequence of the genome of an organism, virus, or extrachromosomal DNA.
  •  Mutations result from errors during DNA replication or other types of damage to DNA such as may be caused by exposure to radiation or carcinogens.
  • Hence, gene frequency in a population remains stable, unless and until there is a mutation. 
  • So, the correct answer is 'Mutation'.
Multiple choice zoology the paths traversed by life mutational theory of evolution theories of evolution other theories of evolution

The concept of sudden genetic change, which breeds true in an organism is visualized as

  1. Natural selection

  2. Inheritance of acquired characters

  3. Mutation

  4. Independent assortment
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The concept of sudden genetic change, which breeds true in an organism is visualized as a mutation. Any sudden or spontaneous change in character which is inheritable is known as mutation. It is defined as the changing of the structure of a gene, resulting in a variant form which may be transmitted to subsequent generations, caused by the alteration of single base units in DNA, or the deletion, insertion, or rearrangement of larger sections of genes or chromosomes.

So, the correct answer is option C.

Multiple choice zoology the paths traversed by life mutational theory of evolution theories of evolution other theories of evolution

After observing the variations Hugo De Vries first of all described the mutation in

  1. Oenothera lamarckiana

  2. Neurospora crassa

  3. Pisum sativum

  4. Drosophila melanogaster
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Hugo de Vries studied inheritance of flower colour in Oenothera lamarckiana (evening primrose) and proposed mutation theory that says that mutations are sudden, random, and inheritable and discontinuous variations which serve as raw material for evolution. 

George Beadle and Edward Tatum gave molecular definition of a gene while working on nutritional mutants in Neurospora crassa and proposed the one gene–one enzyme hypothesis.
Mendel conducted hybridization experiments on garden pea plant, Pisum sativum and proposed “Laws of inheritance” but did not observe any mutations.
Morgan and Muller identified radioactive nature of X-rays to induce point mutations while working on sex linked inheritance in Drosophila. 
So, the correct answer is option A.

Multiple choice zoology the paths traversed by life mutational theory of evolution theories of evolution other theories of evolution

In nature, the occurrence of mutations are

  1. Mostly harmful

  2. Mostly useful

  3. Mostly neutral

  4. Mostly neutral or harmful
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Example for harmful effect of mutation: Oncogenes are harmful mutations can cause cells to become malignant and can ultimately lead to cancer. Mutations are mostly harmful and sometimes neutral (silent mutations)

So, the correct answer is 'Mostly neutral or harmful'