MCQ Bank

A fossil is the preserved remains, impressions, or traces of organisms that lived in the past. Fossils provide evidence about ancient life and evolutionary history.

BT201 Final Term AI Solved

Q221

The half-life of Potassium-40 used in dating ancient rocks is:

A) 1.3 billion years
B) 3.5 billion years
C) 5,730 years
D) 704 million years

AI Explanation

Potassium-40 has a half-life of about 1.3 billion years and is commonly used to date very old rocks. Its slow radioactive decay makes it useful for geological timescales.

BT201 Final Term AI Solved

Q222

A chromosomal change that deletes or rearranges many loci is usually:

A) Harmful
B) Necessary
C) Beneficial
D) Harmless

AI Explanation

Large chromosomal changes that delete or rearrange many loci often disrupt important genes and cellular functions. Therefore, they are usually harmful to the organism.

BT201 Final Term AI Solved

Q223

What is meant by “introduced species”?

A) A native species evolving into another
B) A species created by artificial selection
C) A species that goes extinct
D) A species brought into a new ecosystem

AI Explanation

An introduced species is a non-native species moved by humans or other means into an area where it did not previously exist. Some introduced species can become invasive and affect native ecosystems.

BT201 Final Term AI Solved

Q224

Stromatolites are formed due to:

A) Volcanic eruptions
B) Breakdown of trilobites
C) Calcified microbial deposits
D) Sedimentation of sand

AI Explanation

Stromatolites are layered structures formed by ancient microbial communities, especially cyanobacteria, that trap and bind sediments. They are among the earliest evidence of life on Earth.

BT201 Final Term AI Solved

Q225

What was the Cambrian explosion?

A) A meteorite impact
B) A mass extinction event
C) A massive volcanic eruption
D) Rapid appearance of many new animal body plans

AI Explanation

The Cambrian explosion refers to a period about 541 million years ago when many major animal groups appeared rapidly in the fossil record. It represents a major diversification of life forms rather than an extinction or geological disaster.

BT201 Final Term AI Solved

Q226

Who proposed that Earth's early atmosphere was a reducing environment?

A) Wegener and Haldane
B) Alfred Wegener and Charles Darwin
C) Oparin and Haldane
D) Stanley Miller and Louis Pasteur

AI Explanation

Alexander Oparin and J. B. S. Haldane proposed that the early Earth's atmosphere was a reducing environment with little or no free oxygen. Their ideas supported hypotheses about the chemical origin of life.

BT201 Final Term AI Solved

Q227

Why can’t natural selection produce perfect organisms?

A) It works on ideal genetic codes
B) It only selects from existing variation
C) It always creates new genes
D) It removes all harmful mutations

AI Explanation

Natural selection acts on variations that already exist within a population. It cannot create perfect organisms because evolution is limited by available genetic changes and environmental conditions.

BT201 Final Term AI Solved

Q228

Which of the following is a possible consequence of DNA segment inversion?

A) Chromosome duplication
B) New chromosome formation
C) RNA degradation
D) Change in protein structure

AI Explanation

DNA segment inversions can alter the order of genes and regulatory regions, potentially affecting gene expression and protein structure. They do not necessarily duplicate chromosomes or form new chromosomes.

BT201 Final Term AI Solved

Q229

Which of the following is a condition for a population to be in Hardy-Weinberg equilibrium?

A) Natural selection
B) No genetic drift
C) High migration
D) Constant mutation

AI Explanation

Hardy-Weinberg equilibrium requires no evolutionary forces such as genetic drift, natural selection, mutation, or gene flow. Under these conditions, allele frequencies remain constant across generations.

BT201 Final Term AI Solved

Q230

Which is NOT a way natural selection affects populations?

A) Creating adaptive features
B) Altering allele frequencies
C) Changing phenotype display
D) Reducing genetic drift

AI Explanation

Natural selection can create adaptive features, alter allele frequencies, and change observable traits in populations. Reducing genetic drift is not a direct effect of natural selection.

BT201 Final Term AI Solved

Q231

Which of the following statements is true about prokaryotes?

A) They lack membrane-bound organelles
B) They have many organelles
C) They have a well-defined nucleus
D) They are multicellular organisms

AI Explanation

Prokaryotes, such as bacteria and archaea, do not contain membrane-bound organelles or a true nucleus. Their genetic material is located in a nucleoid region within the cell.

BT201 Final Term AI Solved

Q232

Genetic variation is essential for which evolutionary process?

A) Migration
B) Natural selection
C) Extinction
D) Photosynthesis

AI Explanation

Genetic variation provides the differences among individuals that natural selection acts upon. Without variation, populations cannot adapt effectively to changing environments.

BT201 Final Term AI Solved

Q233

In a phylogenetic tree, what does a node represent?

A) An extinct species
B) A common ancestor where lineage splits
C) A fossil
D) A branch ending

AI Explanation

In a phylogenetic tree, a node represents a point where evolutionary lineages diverge from a shared ancestor. It indicates relationships among groups of organisms.

BT201 Final Term AI Solved

Q234

What does similarity in DNA sequences between two organisms suggest?

A) Same lifespan
B) Similar habitat
C) Common ancestry
D) Random mutations

AI Explanation

Similar DNA sequences between organisms usually indicate that they share an evolutionary ancestor. The greater the genetic similarity, the more closely related the organisms are likely to be.

BT201 Final Term AI Solved

Q235

Which of the following is NOT an example of genetic variation?

A) Eye color
B) Skin tanning from the sun
C) Blood type
D) Leaf modification in plants

AI Explanation

Skin tanning is an acquired environmental response and does not represent inherited genetic variation. Eye color, blood type, and plant leaf modifications can be influenced by genetic differences.

BT201 Final Term AI Solved

Q236

Gene flow usually occurs due to:

A) Mutation of alleles
B) Reproduction within a clone
C) Migration of individuals or gametes
D) Isolation of species

AI Explanation

Gene flow occurs when alleles move between populations through the migration of individuals or the transfer of gametes. This process can introduce new genetic variation into a population.

BT201 Final Term AI Solved

Q237

Who proposed the concept of "survival of the fittest"?

A) Lamarck
B) Darwin
C) Malthus
D) Wallace

AI Explanation

Charles Darwin used the idea of natural selection to explain how organisms with favorable traits survive and reproduce more successfully. The phrase 'survival of the fittest' is commonly associated with Darwin's evolutionary theory.

BT201 Final Term AI Solved

Q238

Which of the following structures is an example of convergent evolution?

A) Roots of monocots and dicots
B) Wings of bat and bird
C) Beaks of Darwin’s finches
D) Human arm and whale flipper

AI Explanation

Bat and bird wings perform a similar function but evolved independently in different lineages, making them examples of convergent evolution. Their similar adaptations arose due to similar environmental pressures.

BT201 Final Term AI Solved

Q239

According to the video, how does molecular evidence relate to structural and fossil evidence?

A) It ignores it
B) It contradicts it
C) It complements it
D) It replaces it

AI Explanation

Molecular evidence, such as DNA comparisons, supports and adds to structural and fossil evidence when studying evolution. These different types of evidence together provide a stronger understanding of evolutionary relationships.