Biology

Biological Reproduction

806 Questions

Biological reproduction encompasses processes like asexual and sexual reproduction, alternation of generations, and specific mechanisms in plants and fungi. This topic is fundamental for biology paper preparation in various competitive exams. Practice these questions to solidify your understanding.

Asexual reproduction structuresPlant and fungi life cyclesCloning and fertilizationReproductive terminology

Biological Reproduction Questions

Multiple choice

The oocysts of Cystoisospora belli are long and oval-shaped. Which among the following statements regarding the life cycle of Cystoisospora belli is incorrect?

  1. Trophozoites develop into schizonts.

  2. The sporozoites invade the epithelial cells of the allimentary.

  3. Transmission occurs when these mature oocysts are ingested.

  4. An oocyst with two sporoblasts is released in the stool of infected person.

  5. Each sporocyst divides twice, resulting in four sporozoites.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

An oocyst with one sporoblast is released in stool of infected person.After the oocyst has been released, the sporoblast matures further and divides into two.

Multiple choice

The life cycle of dinoflagellates is multi-staged. Which among the following statements regarding the life cycle of dinoflagellates is false?

  1. Vegetative fission dominates yielding motile diploid schizonts.

  2. The schizonts act as gametes.

  3. The diploid zygote constructs a new theca and resumes its motility as a planozygote.

  4. In several species, the zygote theca becomes much thicker and considerably larger than the vegetative theca.

  5. Following a period of obligate dormancy, the protoplast excysts.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

During periods favoured by rapid growth and population expansion, vegetative fission dominates yielding motile haploid schizonts.

Multiple choice

The most common mode of reproduction in diatoms is asexual. Which among the following diatoms differs from closely related species by its sexual reproduction and movement in response to light?

  1. Craspedodiscus elegans

  2. Bacteriastrum delicatulum

  3. Craticula

  4. Tabellaria

  5. Pinnularia
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Craticula is a genus of diatom that lies on or in the top layers of sediments in the freshwater to brackish water environments it inhabits.In addition to frustule morphology the genus differs from closely related species by its sexual reproduction and movement in response to light.

Multiple choice

Which among the following statements does not characterise diatoms?

  1. Araphid pennate diatoms are capable of gliding movement.

  2. The daughter cell that receives the original epitheca remains of the same size as the parent.

  3. The most common mode of reproduction in diatoms is asexual by cell division.

  4. The epicingulum and hypocingulum are collectively known as the girdle.

  5. The frustule is frequently in a high state of differentiation in diatoms.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Raphid pennate diatoms are capable of gliding movement that is caused by the secretion of mucopolysaccharides, derived from vesicles or crystalline bodies, through the raphe. Araphid pennate diatoms lack a raphe and posses a central, unornamented area known as the sternum or pseudoraphe. No centric diatom has a raphe.

Multiple choice

Which among the following statements regarding the life cycle of red algae is FALSE?

  1. The spores of a sporophyte produce either of the tetrasporophytes.

  2. The gametophyte may replicate using carpospores.

  3. Carpospores may also germinate directly into thalloid gametophytes.

  4. They display alternation of generations.

  5. Red algae lack motile sperm.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The gametophyte may replicate using monospores, but produces sperm in spermatangia, and eggs in carpogonium.

Multiple choice

Regarding the reproduction in sponges, which of the following statements is INCORRECT?

  1. In the sponges the sperm are produced by collencytes.

  2. During spawning, sperm burst out of their cysts and are expelled via the osculum.

  3. Gemmules are aggregates of sponge tissue and food.

  4. Only a sponge fragment containing both collencytes and archeocytes will regenerate.

  5. Freshwater gemmules may also include phytosynthesising symbionts.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Most sponges are hermaphrodites (function as both sexes simultaneously), although sponges have no gonads (reproductive organs). Sperm are produced by choanocytes or entire choanocyte chambers that sink into the mesohyl and form spermatic cysts while eggs are formed by transformation of archeocytes, or of choanocytes in some species.

Multiple choice

Spirogyra reproduces by ___________.

  1. budding

  2. fragmentation

  3. gamete formation

  4. vegetative propogation

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

Yes, it is the correct answer. The plant body is divided into smaller fragments. Each fragment then develops into a new plant.

Multiple choice

In which type of reproduction, two parents are involved?

  1. Budding

  2. Fragmentation

  3. Spore formation

  4. Vegetative propogation

  5. Sexual
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Yes, when two parents are involved in the process, it is called sexual reproduction. Two gametes, viz. male and female gametes, are formed.

Multiple choice

The diploidy in higher animals is maintained by

  1. plasmogamy

  2. syngamy

  3. dichogamy

  4. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Diploidy (2n chromosome number) in higher animals is maintained by syngamy - the fusion of male and female gametes during fertilization. This restores the diploid state in the zygote. Plasmogamy is fungal cytoplasm fusion, and dichogamy refers to timing differences in sexual organ maturity.

Multiple choice

During unfavorable conditions Amoeba reproduces through:

  1. binary fission

  2. sporulation

  3. multiple fission

  4. conjugation

  5. budding
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Amoeba reproduces by multiple fission (sporulation) during unfavorable conditions, forming a protective cyst and producing many amoebulae. Binary fission occurs during favorable conditions. Conjugation is a ciliate protozoan process, not amoeboid. Budding occurs in organisms like Hydra and yeast.

Multiple choice

In Hydra, reproduction occurs in favourable conditions by:

  1. budding

  2. gametes

  3. gemules

  4. binary fission

  5. multiple fission
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Hydra reproduces asexually by budding during favorable conditions when food is abundant. A small outgrowth (bud) develops into a complete organism and detaches. Sexual reproduction (gametes) occurs during unfavorable conditions. Gemmules are sponge structures, not hydra.

Multiple choice

Identical twins arise when two

  1. cells develop independently from the same zygote

  2. gametes develop independently

  3. ova develop independently

  4. sperms develop independently
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Identical (monozygotic) twins develop from a single fertilized egg (zygote) that splits into two embryos, each developing independently. They don't come from separate gametes, ova, or sperm - those would produce fraternal (dizygotic) twins or separate siblings.

Multiple choice

Sexual reproduction leads to:

  1. genetic recombination

  2. polyploidy

  3. aneuploidy

  4. euploidy

  5. none of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Genetic recombination is the production of offspring with combinations of traits that differ from those found in either parent. In eukaryotes, genetic recombination during meiosis can lead to a novel set of genetic information that can be passed on from the parents to the offspring.

Multiple choice

Mosses occur in moist places because :

  1. they can not grow on land

  2. their gametes fuse in water

  3. they lack vascular tissue

  4. they lack root and stomata

  5. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Mosses occur in moist places because they require water for fertilisation. Their gametes fuse in water.