Chapter 3 — Reproduction in Living Organisms · Biology. These are 10 questions from the Magmo3 bank on this lesson, from easy to hard. Solve each one, then open "Show answer and explanation". Magmo3 has 34 questions on this lesson, each with an explanation.
The onion is an example of vegetative reproduction by...
Correct answer: (A) A bulb
Explanation: The onion is a short underground stem surrounded by fleshy scale leaves that store food, called a bulb, which forms new plants.
The type of cell division that occurs in asexual reproduction is...
Correct answer: (C) Mitosis
Explanation: Asexual reproduction relies on mitosis, which produces cells identical to the parent with the same number of chromosomes.
The starfish can replace the missing parts of its body by...
Correct answer: (C) Regeneration
Explanation: The starfish has the ability to regenerate, and a severed arm together with part of the central disc can form a complete new individual.
What is the similarity between fission and budding?
Correct answer: (A) Both are asexual reproduction by a single parent
Explanation: Fission and budding are both asexual reproduction by a single parent and by mitosis, and the resulting individuals are genetically identical.
Grafting, cutting, and layering are all examples of...
Correct answer: (A) Artificial vegetative reproduction
Explanation: Grafting, cutting, and layering are methods of artificial vegetative reproduction (carried out by humans) to propagate desired plants.
The life plant (Bryophyllum) is distinguished by forming buds on...
Correct answer: (A) The leaf margins
Explanation: Bryophyllum forms small buds on the margins of its leaves, which fall to the ground and form new plants (vegetative reproduction by leaves).
The ginger plant reproduces vegetatively by a horizontal underground stem called a...
Correct answer: (A) Rhizome
Explanation: Ginger reproduces by a rhizome, which is a thick horizontal underground stem bearing buds that grow into new plants.
A plant grown by vegetative reproduction is identical to the original plant, which is useful for the farmer in order to...
Correct answer: (D) Preserve the traits of a superior variety such as taste and yield
Explanation: Vegetative reproduction produces exact copies, so it guarantees passing the good variety's traits (such as fruit quality) to the new plants unchanged.
A bacterium reproduces by binary fission every 20 minutes under ideal conditions. Starting from one bacterium, how many bacteria are present after 2 hours, and how are they related to the original cell?
Correct answer: (C) 64 bacteria, all genetically identical to it
Explanation: 2 hours = 120 minutes = 6 divisions, and each division doubles the number: 2⁶ = 64. Binary fission copies the genetic material of one parent and splits it equally, so all the offspring are identical to it.
Assume every piece able to regenerate does so: a Planaria is cut lengthwise into two halves, a Hydra is cut across into three pieces, one arm of a sea star is cut off with a piece of its central disc, and a crab loses one leg. How many complete animals will there finally be?
Correct answer: (C) 8 animals
Explanation: Each Planaria half and each Hydra piece grows into a new individual (2 + 3). The arm with part of the central disc grows into a whole sea star while the original star regrows its arm (2), but in crustaceans regeneration only restores the lost part, so there is still one crab: 2 + 3 + 2 + 1 = 8.
The first 10 questions in every subject are free, each with an explanation.