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

Which of the following statements does NOT characterise RNA editing in both plants and animals?

  1. After editing, all amino acids at the number 228 position are converted to cysteine.

  2. The RNA editing events occur at random in the transcript.

  3. The primary benefit of RNA editing could be evolutionary conservation of protein structure.

  4. Plant mitochondria do not use the universal genetic code.

  5. Editing converts a tryptophan codon to methionine codon.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Structural RNAs such as tRNAs and rRNAs are also affected. Editing can convert a tryptophan codon to arginine codon (CGG to UGG).

Multiple choice

Jumping genes are referred as

  1. exons

  2. introns

  3. mutons

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

Transposons, often called jumping genes, are DNA sequences that can change their position within a genome. They were first discovered by Barbara McClintock in maize.

Multiple choice

Among which of the following types of speciation, genetic drift is supposed to play a significant role?

  1. Allopatric speciation

  2. Peripatric speciation

  3. Parapatric speciation

  4. Sympatric speciation

  5. Natural speciation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In peripatric speciation, new species are formed in isolated, smaller peripheral populations that are prevented from exchanging genes with the main population. Genetic drift is often proposed to play a significant role in peripatric speciation.

Multiple choice

We are all unique. Every one of us has a unique combination of traits. Which among the following variable traits are influenced by a combination of genes and environmental factors?

  1. Earlobe attachment

  2. Tongue rolling

  3. Dimples

  4. Handedness

  5. Freckles
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Some people can curl up the sides of their tongue to form a tube shape. Tongue rolling is controlled by a single gene. However, people can learn to roll their tongue as they get older, suggesting that environmental factors also influences the trait.

Multiple choice

Which of the following is not true about hybridisation?

  1. Hybridisation refers to the crossing between genetically dissimilar plants.

  2. Crossing between two different species of the same genus is called inter specific.

  3. Crop production can be decreased by biotic and abiotic stresses under different situations.

  4. None of these

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Hybridisation refers to the crossing between genetically dissimilar plants. Crop production can be decreased by biotic and abiotic stresses under different situations.

Multiple choice

The individuals morphology, or physiological properties, indicates his __________.

  1. phenotype

  2. genotype

  3. haploid no. of chromosomes

  4. diploid no. of chromosomes
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Phenotype is any observable characteristic or trait of an organism: such as its morphology, development, biochemical or physiological properties, behaviour, and products of behaviour (such as a bird's nest). Phenotypes result from the expression of an organism's genes as well as the influence of environmental factors and the interactions between the two.

Multiple choice

Continuous inbreeding is not recommended for a small population because

  1. it makes the genetic diversity comparatively small

  2. it makes the genetic diversity comparatively larger and richer

  3. it enhances the rate of mutations

  4. it decreases the rate of mutations
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Usually closely related individuals are genetically similiar. When they mate, there is a less chance of occurrence of significantly new genetic combinations. Compared to crossbreeding, there will be reduced genetic diversity and increased homozygosity.