Freshwater plant called water lily

Marine plant called water propagules

REPRODUCTION IN ORGANISMS MCQs for NEET UG BIOLOGY — Medium, Page 2

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Number of parents involved in asexual and usual sexual reproductions respectively?

View answer and explanation

Correct option: B

1,2

Option B (

1,2

) is correct because asexual reproduction involves one parent, while sexual reproduction usually involves two.

Solution approach

Correct Answer + Core Reason: $1,2$ . Asexual reproduction involves one parent, while sexual reproduction usually involves two.

Step-by-Step Solution:

Step 1: Asexual reproduction involves a single parent and produces offspring that are genetically identical to the parent.

Step 2: Sexual reproduction typically involves two parents, each contributing genetic material to the offspring.

Step 3: Therefore, the number of parents involved in asexual and sexual reproduction are 1 and 2, respectively.

Why other options are wrong:
- Option A: $2,1$ : Incorrect, asexual reproduction involves one parent, not two.
- Option C: $2,2$ : Incorrect, asexual reproduction involves one parent.
- Option D: $1,1$ : Incorrect, sexual reproduction usually involves two parents.

Key Concepts:
- Asexual reproduction
- Sexual reproduction
- Number of parents

Memory Aids:
- Asexual = 1, Sexual = 2 (think A1, S2)

Quick Tips:
- Remember the fundamental difference in parental involvement between asexual and sexual reproduction.

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There is no natural death in single celled organisms like Amoeba and bacteria because

View answer and explanation

Correct option: C

Parental body is distributed among the offspring

Option C is correct because in single-celled organisms like Amoeba and bacteria, reproduction often occurs through binary fission, where the parental body divides and its components are distributed among the offspring, effectively eliminating the original parent cell through transformation.

Solution approach

Correct Answer + Core Reason: Parental body is distributed among the offspring. In binary fission, the parent cell divides into daughter cells, so the parent ceases to exist as an individual.

Step-by-Step Solution:

Step 1: Recall the mode of reproduction in Amoeba and bacteria (binary fission).

Step 2: Describe the process of binary fission: the parent cell divides into two identical daughter cells.

Step 3: Explain that the parent cell's cytoplasm and genetic material are equally distributed between the daughter cells.

Step 4: Emphasize that the original parent cell no longer exists after division; it has been transformed into the daughter cells.

Step 5: Conclude that there is no natural death because the parent cell's substance is passed on to the offspring.

Why other options are wrong:
- Option A: They cannot reproduce sexually. The absence of sexual reproduction doesn't directly explain the lack of natural death in these organisms. It's the mode of asexual reproduction that matters.
- Option B: They reproduce by binary fission. While correct, this is not the complete explanation. The key is what happens to the parental body during binary fission.
- Option D: They are microscopic. Size is irrelevant to the concept of natural death in this context.

Key Concepts:
- Binary fission
- Asexual reproduction
- Distribution of parental material

Memory Aids:
- Binary Fission = Parent Splits = No Death

Quick Tips:
- Focus on the fate of the parent cell during asexual reproduction.

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In

Amorphophallus

and

Yucca

, the moth lay egg into the

View answer and explanation

Correct option: A

Locule of ovary

Option A (Locule of ovary) is correct because the female moth deposits its eggs inside the locule of the ovary, ensuring the developing larvae have access to the developing seeds for food.

Solution approach

Correct Answer + Core Reason: Locule of ovary. The moth lays its eggs into the locule of the ovary in $Amorphophallus$ and $Yucca$ .

Step-by-Step Solution:

Step 1: Recall the mutualistic relationship between Yucca/Amorphophallus and moths.

Step 2: Identify the location where the moth lays its eggs.

Step 3: Recognize that the locule of the ovary provides protection and food for the developing larvae.

Step 4: Conclude that the locule of the ovary is the correct answer.

Why other options are wrong:
- Option B: On stigma - The stigma is the receptive surface for pollen, not where the moth lays eggs.
- Option C: Into the fruit wall - The moth lays eggs inside the ovary, which later develops into the fruit, but not directly into the fruit wall initially.
- Option D: On style - The style connects the stigma to the ovary, not where the moth lays eggs.

Key Concepts:
- Mutualism
- Pollination
- Plant reproduction
- Insect-plant interactions

Memory Aids:
- Think of the \"ovary\" as a safe place for the moth's \"ova\" (eggs).

Quick Tips:
- Consider the specific roles of different floral parts in reproduction.

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Assertion: Algae and fish produce a large number of gametes.
Reason: They show internal fertilization.

View answer and explanation

Correct option: C

If Assertion is true but Reason is false

Option C (If Assertion is true but Reason is false) is correct because Algae and fish produce a large number of gametes, but they show external fertilization (mostly), not internal fertilization.

Solution approach

Correct Answer + Core Reason: If Assertion is true but Reason is false. Algae and fish produce many gametes, but they usually exhibit external fertilization.

Step-by-Step Solution:

Step 1: Analyze the Assertion: Algae and fish produce a large number of gametes. This is generally true. Many aquatic organisms, including algae and fish, release a large number of gametes into the water to increase the chances of fertilization.

Step 2: Analyze the Reason: They show internal fertilization. This is generally false. Most algae and fish exhibit external fertilization, where the eggs and sperm are released into the water for fertilization to occur. Internal fertilization is less common in these groups.

Step 3: Determine if the Reason is the correct explanation for the Assertion. The Reason is not the correct explanation. The large number of gametes produced is an adaptation to the challenges of external fertilization, where many gametes may be lost or fail to find each other.

Step 4: Conclusion: The Assertion is true, but the Reason is false.

Why other options are wrong:
- Option A (If both Assertion and Reason are true and Reason is the correct explanation of Assertion): Incorrect because the Reason is false.
- Option B (If both Assertion and Reason are true but Reason is not the correct explanation of Assertion): Incorrect because the Reason is false.
- Option D (If both Assertion and Reason are false): Incorrect because the Assertion is true.

Key Concepts:
- Gamete Production
- External Fertilization
- Internal Fertilization

Memory Aids:
- External fertilization = many gametes.

Quick Tips:
- Consider the mode of fertilization when analyzing gamete production strategies.

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Which of the following statement support the view that elaborate sexual reproductive processes appeared much later in organic evolution?
I. Lower groups of organisms have complex body design
II. Asexual reproduction is common in lower groups
III. Asexual reproduction is common in higher groups of organisms
IV. High incidences of sexual reproduction are visible in angiosperms and vertebrates

View answer and explanation

Correct option: C

II and IV

Option C (II and IV) is correct because the prevalence of asexual reproduction in lower organisms and the high incidence of sexual reproduction in angiosperms and vertebrates suggest that elaborate sexual reproduction appeared later in evolution.

Solution approach

Correct Answer + Core Reason: II and IV. Asexual reproduction in lower groups and high sexual reproduction in angiosperms and vertebrates support the later appearance of sexual reproduction.

Step-by-Step Solution:

Step 1: Analyze Statement I. Lower groups of organisms do not necessarily have complex body designs. Some have simple designs.

Step 2: Analyze Statement II. Asexual reproduction is common in lower groups of organisms, suggesting it was an earlier form of reproduction.

Step 3: Analyze Statement III. Asexual reproduction is not common in higher groups of organisms; sexual reproduction is more prevalent.

Step 4: Analyze Statement IV. High incidences of sexual reproduction in angiosperms and vertebrates suggest that sexual reproduction became more dominant later in evolution.

Why other options are wrong:
- Option A (I and II): Statement I is incorrect, so this option is incorrect.
- Option B (I and IV): Statement I is incorrect, so this option is incorrect.
- Option D (II and III): Statement III is incorrect, so this option is incorrect.

Key Concepts:
- Asexual reproduction
- Sexual reproduction
- Organic evolution
- Reproductive strategies

Memory Aids:
- Asexual = Ancient; Sexual = Sophisticated.

Quick Tips:
- Consider the evolutionary history of reproductive strategies when answering such questions.

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During embryogenesis the zygote undergoes

View answer and explanation

Correct option: D

1) followed by 3)

Option D (1) followed by 3)) is correct because during embryogenesis, the zygote undergoes cell division (mitosis) to increase cell number, followed by cell differentiation to form specialized tissues and organs.

Solution approach

Correct Answer + Core Reason: 1) followed by 3). During embryogenesis, the zygote undergoes cell division (mitosis) followed by cell differentiation.

Step-by-Step Solution:

Step 1: Define Embryogenesis. Embryogenesis is the process of development of an embryo from the zygote.

Step 2: Cell Division (Mitosis). The zygote undergoes rapid cell division through mitosis to increase the number of cells. This process is called cleavage.

Step 3: Cell Differentiation. As the embryo develops, cells begin to differentiate, meaning they become specialized to perform specific functions. This leads to the formation of different tissues and organs.

Why other options are wrong:
- Option A (Cell division (mitosis)): While cell division (mitosis) is a part of embryogenesis, it is not the only process. Cell differentiation is also crucial.
- Option B (Cell division (meiosis)): Meiosis is involved in gamete formation, not embryogenesis.
- Option C (Cell differentiation): While cell differentiation is a part of embryogenesis, it occurs after cell division (mitosis).

Key Concepts:
- Embryogenesis
- Mitosis
- Cell differentiation
- Zygote

Memory Aids:
- Embryogenesis = Embryo formation (division then differentiation).

Quick Tips:
- Remember the sequence of events in embryogenesis: cell division (mitosis) followed by cell differentiation.

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Offsprings formed by sexual reproduction exhibit more variation than those formed by asexual reproduction because

View answer and explanation

Correct option: C

Genetic material comes from two parents of same species

Option C (Genetic material comes from two parents of same species) is correct because sexual reproduction involves the fusion of gametes from two parents, leading to genetic recombination and increased variation in offspring.

Solution approach

Correct Answer + Core Reason: Genetic material comes from two parents of same species. Sexual reproduction involves genetic recombination from two parents, leading to more variation.

Step-by-Step Solution:

Step 1: Understand Sexual Reproduction. Sexual reproduction involves the fusion of male and female gametes, each carrying half the genetic material of the parent.

Step 2: Understand Asexual Reproduction. Asexual reproduction involves a single parent and produces offspring that are genetically identical to the parent (clones).

Step 3: Explain the Source of Variation. In sexual reproduction, genetic material from two parents combines, resulting in new combinations of genes and increased variation in the offspring. This variation is due to crossing over, independent assortment, and random fertilization.

Why other options are wrong:
- Option A (Sexual reproduction is a lengthy process): The length of the process does not directly cause variation.
- Option B (Gametes of parents have quantitatively different genetic composition): Gametes have qualitatively different genetic composition, not quantitatively.
- Option D (Greater amount of DNA is involved in sexual reproduction): The amount of DNA is not the primary reason for increased variation; it's the recombination of genetic material.

Key Concepts:
- Sexual reproduction
- Asexual reproduction
- Genetic variation
- Genetic recombination

Memory Aids:
- Sexual = Sharing = Variation.

Quick Tips:
- Remember that genetic recombination is the key to variation in sexual reproduction.

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Clones are similar with their parents in?

View answer and explanation

Correct option: C

Both 1 and 2

Option C (Both 1 and 2) is correct because clones are genetically and morphologically identical to their parents.

Solution approach

Correct Answer + Core Reason: Both 1 and 2. Clones are morphologically and genetically similar to their parents.

Step-by-Step Solution:

Step 1: Define clone: An organism or cell produced asexually from one ancestor or stock, to which they are genetically identical.

Step 2: Clones are morphologically similar to their parents because they inherit the same genetic information that determines their physical characteristics.

Step 3: Clones are genetically similar to their parents because they are produced by asexual reproduction, which does not involve genetic recombination.

Step 4: Therefore, clones are similar to their parents both morphologically and genetically.

Why other options are wrong:
- Option A: Morphologically is incorrect because clones are also genetically similar.
- Option B: Genetically is incorrect because clones are also morphologically similar.
- Option D: Amphibolically is incorrect because this term is not relevant to the similarity of clones to their parents.

Key Concepts:
- Clone
- Asexual reproduction
- Genetic similarity
- Morphological similarity

Memory Aids:
- Clones: Genetically and Morphologically Identical to Parents

Quick Tips:
- Remember that clones are produced by asexual reproduction and are identical to their parents.

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Bamboo species flower only in

View answer and explanation

Correct option: A

50-100 yrs

Option A (50-100 yrs) is correct because bamboo species are known to flower only once in their lifetime, typically within a range of 50 to 100 years.

Solution approach

Correct Answer + Core Reason: 50-100 yrs. Bamboo species are known for their long flowering cycle.

Step-by-Step Solution:

Step 1: Recall the flowering cycle of bamboo.

Step 2: Bamboo species typically flower once every 50-100 years.

Why other options are wrong:
- Option B: 25-50 years is too short for most bamboo species.
- Option C: 75-100 years is within the correct range, but 50-100 is more inclusive.
- Option D: 60-80 years is within the correct range, but 50-100 is more inclusive.

Key Concepts:
- Flowering cycle
- Bamboo reproduction

Memory Aids:
- Think of bamboo's long lifespan and infrequent flowering.

Quick Tips:
- Remember that bamboo flowering is a rare and long-awaited event.

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Terror of Bengal is

View answer and explanation

Correct option: C

Aquatic plant called water hyacinth

Option C is correct because water hyacinth is an aquatic plant that spreads rapidly and causes significant ecological damage, hence the name 'Terror of Bengal'.

Solution approach

Correct Answer + Core Reason: Aquatic plant called water hyacinth. Water hyacinth is an invasive species that causes ecological damage.

Step-by-Step Solution:
Step 1: Recall the characteristics of water hyacinth: Water hyacinth (Eichhornia crassipes) is an aquatic plant that is known for its rapid growth and ability to form dense mats on the surface of water bodies.
Step 2: Explain why it is called "Terror of Bengal": Its rapid growth can block sunlight, deplete oxygen, and hinder navigation, causing significant ecological and economic problems, particularly in regions like Bengal.

Why other options are wrong:
- Option A: Freshwater plant called water lily. Water lilies are not typically referred to as the "Terror of Bengal".
- Option B: Marine plant called water propagules. This is not a specific plant and does not relate to the "Terror of Bengal".
- Option D: None of the above. Water hyacinth is the correct answer.

Key Concepts:
- Invasive species
- Water hyacinth
- Ecological impact

Memory Aids:
- Terror of Bengal = Water hyacinth

Quick Tips:
- Remember the ecological impact of invasive species.

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