(2026) Actual Q&A PDF | Portage Learning
Module 1
1. Who is credited with formulating the theory of natural selection?
A) Charles Darwin
B) Gregor Mendel
C) James Watson
D) Francis Crick
Correct Answer: A) Charles Darwin
Rationale: Darwin’s 1859 On the Origin of Species detailed natural selection as
the mechanism of evolution. Mendel discovered gene inheritance, and Watson
and Crick elucidated DNA structure. Darwin’s theory remains foundational.
2. According to Darwin, what is the primary consequence of the struggle for
existence?
A) Extinction of all species
B) Survival of individuals with the most adaptive traits
C) Equal reproductive success for all organisms
D) Elimination of genetic variation
Correct Answer: B) Survival of individuals with the most adaptive traits
Rationale: In a crowded environment, organisms compete for limited resources;
those with favorable variations survive and reproduce, passing advantageous
traits to offspring. This is the core of natural selection.
,3. Gregor Mendel’s classic heredity experiments used which organism?
A) Fruit flies
B) Mice
C) Pea plants
D) Zebrafish
Correct Answer: C) Pea plants
Rationale: Mendel chose the garden pea (Pisum sativum) because of its distinct
traits, rapid generation time, and ability to control pollination. His work
established the laws of inheritance.
4. Mendel proposed that inherited factors occur in pairs; what term describes
alternative forms of these factors?
A) Genome
B) Chromosome
C) Locus
D) Allele
Correct Answer: D) Allele
Rationale: An allele is a variant of a gene. Mendel’s “factors” are now known as
genes, and different versions (e.g., tall vs. short) are alleles. Genotype refers to
the combination of alleles.
5. Which two scientists are most directly associated with the formulation of the
cell theory?
, A) Schleiden and Schwann
B) Darwin and Wallace
C) Watson and Crick
D) Mendel and Morgan
Correct Answer: A) Schleiden and Schwann
Rationale: Matthias Schleiden (1838) and Theodor Schwann (1839) proposed
that all organisms are composed of cells, the basic unit of life. Their work
established the foundation of modern cell biology.
6. Which of the following is a correct statement of the cell theory? A)
All organisms are composed of cells.
B) All cells arise spontaneously.
C) Cells lack genetic material.
D) Cells function independently of chemical reactions.
Correct Answer: A) All organisms are composed of cells.
Rationale: The first tenet of cell theory states that all living things consist of one
or more cells. Spontaneous generation was disproved; cells contain DNA and
rely on chemical reactions.
7. According to the cell theory, where do the chemical reactions responsible for
life occur?
A) In extracellular fluid
B) In the nucleus only