Question
The image shows the nucleus of a cell from the pancreas that is surrounded by endoplasmic reticulum.
What describes this nucleus?
A. It is composed of highly folded internal membranes and a liquid matrix.
B. It contains ribosomes and is the main site of protein synthesis in a cell.
C. It contains membrane-bound organelles.
D. It contains chromatin and is surrounded by a double membrane.
▶️Answer/Explanation
Answer: D
Explanation:
The nucleus is an organelle in eukaryotic cells that holds genetic material in the form of chromatin (uncoiled DNA). It is surrounded by a double membrane, called the nuclear envelope, which has pores that allow molecules like RNA to pass in and out.
Question
The image shows a single Paramecium with food vacuoles that contain ingested cells of the unicellular green alga Chlorella.
What can be deduced about Paramecium?
A. It is an autotroph.
B. It cannot perform all of the functions of life.
C. It carries out heterotrophic nutrition.
D. It is a prokaryote.
▶️Answer/Explanation
Answer: C.
Explanation:
Paramecium is a heterotroph, hence it cannot make its own food like plants (which are autotrophs). Paramecium ingests food from its environment. The food vacuoles are used to digest the ingested food.
Question
Which feature shared by both types of cells – aseptate fungal hyphae and striated muscle cell makes them atypical?
A. Both have cell walls.
B. Both have several nuclei.
C. Both lack membrane-bound organelles.
D. Both are divided into compartments.
▶️Answer/Explanation
Answer. B.
Explanation:
Aseptate fungal hyphae and striated muscle cells are atypical cells because they have multiple nuclei in a single cell.
Question
Which function is accomplished by structures X and Y in the Paramecium?
▶️Answer/Explanation
Answer: B
Explanation:
Structure X: The oral groove (X) is responsible for feeding, where food particles are ingested.
Structure Y: The contractile vacuole (Y) regulates water balance through osmoregulation, supporting metabolism.