Mix Examples -Reproduction in Organisms Questions in English

(D) Pre-fertilization events include all the processes that occur before the fusion of gametes,such as gametogenesis (formation of male and female gametes) and gamete transfer.
Post-fertilization events include all the processes that occur after the fusion of gametes (fertilization),such as the formation of the zygote and embryogenesis (development of the embryo from the zygote).
Therefore,all the provided statements correctly distinguish between these two phases of sexual reproduction.

(N/A) Asexual reproduction: When offspring are produced by a single parent without the involvement of gamete formation or fusion.
Sexual reproduction: When two parents of opposite sex are involved in reproduction,both produce their respective gametes which fuse to form a zygote.
$(b)$ Fission: $A$ process of asexual reproduction in which the nucleus divides first,followed by cytoplasmic division (cytokinesis).
Clones: Genetically and morphologically identical offspring resulting from a single parent through asexual reproduction.

(N/A) Senescent phase: This is the final stage of the life cycle,occurring after the reproductive phase. During this phase,hormonal changes lead to a gradual decline in the production of gametes,eventually leading to death.
$(b)$ Reproductive phase: This phase begins when the reproductive system becomes mature enough to produce functional gametes. The organism is then capable of mating and reproduction. This phase is characterized by significant hormonal changes. In humans,it typically starts at $12$ to $13$ years of age and lasts until $55$ to $60$ years.
$(c)$ Juvenile phase: This is the period of growth and development that an organism undergoes before reaching sexual maturity. During this time,the organism is not yet capable of reproduction. In humans,this phase lasts from birth up to $12$ to $13$ years of age.

(N/A) No,the number of eggs laid by oviparous animals is not necessarily equal to the number of offspring produced by viviparous animals.
$1$. In oviparous animals,the number of eggs varies significantly. For example,fish and frogs lay a large number of eggs to ensure survival against predators,whereas birds like the ostrich lay only one or a few eggs.
$2$. Similarly,in viviparous animals,the number of offspring produced varies. Some animals like humans typically give birth to a single offspring,while others like dogs or cats give birth to multiple offspring at once.
$3$. Therefore,there is no fixed rule that the number of eggs in oviparous animals equals the number of offspring in viviparous animals; it depends on the species,reproductive strategy,and environmental factors.

(C) Offspring formed by asexual reproduction are referred to as clones because they are morphologically and genetically identical to their parent.
This occurs because asexual reproduction involves only a single parent and occurs through mitotic cell division,which does not involve the recombination of genetic material or the formation of gametes.

(N/A) An annual plant has a shorter juvenile phase compared to a perennial plant.
Reason: Annual plants must complete their entire life cycle,including growth,flowering,and seed production,within a single growing season. Therefore,they have a rapid development phase to ensure reproduction before the season ends.

(C) No,there is no direct correlation between the size of an organism and its lifespan.
$(1)$ The mango tree and the peepal tree are of similar size,yet the lifespan of the mango tree is much shorter than that of the peepal tree.
$(2)$ $A$ crow and a parrot are of similar size,yet their lifespans are approximately $15$ years and $140$ years,respectively.

(N/A) In multicellular organisms,cell division is primarily a mechanism for growth,development,and the repair of tissues.
It increases the number of cells within an individual organism,leading to an increase in body size and mass.
Reproduction,on the other hand,is a biological process by which an organism produces offspring to ensure the continuity of its species.
Since cell division in multicellular organisms does not result in the formation of a new,independent individual,it is considered a process of growth rather than a mode of reproduction.

(A) Earthworm: Monoecious (Hermaphrodite).
$(b)$ Chara: Monoecious (Both male and female sex organs are present on the same plant).
$(c)$ Marchantia: Dioecious (Male and female sex organs are present on different thalli).
$(d)$ Cockroach: Dioecious (Male and female individuals are separate).

(N/A) Sexual reproduction is preferred in higher organisms because it promotes genetic diversity through recombination and independent assortment during meiosis.
Genetic variation allows populations to adapt to changing environmental conditions,which is crucial for the survival of complex organisms.
Sexual reproduction facilitates the removal of harmful mutations from the gene pool over generations.
In contrast,asexual reproduction produces clones,which lack genetic diversity and are more susceptible to environmental changes or diseases.
Furthermore,higher organisms have complex body organizations and specialized reproductive systems that are better suited for sexual reproduction,which ensures the long-term evolutionary success of the species.

(A) $=$ Sexual reproduction is a better mode of reproduction.
$\Rightarrow$ It involves the fusion of male and female gametes to produce variants which are not identical to their parents and themselves.
- These variations allow individuals to adapt to the changing environment and ensure a greater survival of the species.
$\Rightarrow$ On the other hand,asexual reproduction allows for little or no variation at all.
- As a result,the individuals produced are identical to their parent.

(B) The lifespan of an organism is defined as the period from its birth to its natural death. It is a biological characteristic that varies among different species. Even if an organism is unicellular,its lifespan is the duration from its origin to its natural death.

(C) The lifespan of the given organisms are as follows:
$1$. Butterfly: $1-2$ weeks.
$2$. Crocodile: $60$ years.
$3$. Parrot: $140$ years.
$4$. Dog: $10-13$ years.
Comparing these,the parrot has the longest lifespan among the options provided.

(A) The lifespan of an organism is the period from birth to the natural death of that organism.
According to biological data,the average lifespan of a tortoise is approximately $100-150$ years.
Therefore,the correct option is $A$.

(D) An offspring is called an exact copy of its parents when it is morphologically and genetically identical to the parent. This phenomenon is known as a $clone$. Clones are produced through asexual reproduction,where a single parent produces offspring without the fusion of gametes,ensuring that the genetic material remains identical to the parent.

(A) The lifespan of an organism is the period from birth to the natural death of an organism.
According to the $NCERT$ biology textbook, the average lifespan of a crocodile is approximately $60$ years.
Therefore, the correct option is $A$.

(A) $Hydra$ is a freshwater organism that primarily reproduces asexually through $Budding$. In this process,a small outgrowth called a bud develops on the parent body,which eventually detaches to form a new individual. Additionally,$Hydra$ can also reproduce through $Fragmentation$,where the body breaks into pieces,and each piece regenerates into a complete organism. Therefore,the correct combination is $Budding$ and $Fragmentation$.

(C) The approximate life spans of the given organisms are as follows:
$1$. Parrot: $\approx 140$ years
$2$. Crocodile: $\approx 60$ years
$3$. Crow: $\approx 15$ years
$4$. Butterfly: $\approx 1-2$ weeks
Arranging these in descending order (from longest to shortest life span): Parrot ($140$ years) $>$ Crocodile ($60$ years) $>$ Crow ($15$ years) $>$ Butterfly ($1-2$ weeks). Therefore,the correct sequence is Parrot $\rightarrow$ Crocodile $\rightarrow$ Crow $\rightarrow$ Butterfly.

(B) Bamboo species are monocarpic plants, meaning they flower only once in their lifetime, usually after $50-100$ years, produce a large number of fruits, and then die. While $Strobilanthes$ $kunthiana$ (Neelakurinji) also flowers once, it does so every $12$ years, whereas the question refers to the general biological phenomenon of monocarpic flowering often associated with bamboo in the context of life history strategies.

(D) Bamboo species are monocarpic plants,meaning they flower and fruit only once in their lifetime.
They generally flower after a long period of vegetative growth,typically ranging from $50$ to $100$ years.
After producing a large number of fruits,the plant dies.
Therefore,the correct range is $50-100$ years.

(B) Sexual reproduction in organisms is generally divided into three distinct stages:
$1$. Pre-fertilization events: These include gametogenesis (formation of gametes) and gamete transfer.
$2$. Fertilization (Syngamy): The fusion of male and female gametes to form a diploid zygote.
$3$. Post-fertilization events: These include the formation of the zygote and embryogenesis (development of the embryo).
Therefore,gametogenesis and gamete transfer are part of pre-fertilization events.

(D) bisexual condition refers to the presence of both male and female reproductive organs in the same organism.
For plants,the term $Monoecious$ is commonly used to describe this condition.
For animals,the term $Hermaphrodite$ is used to describe an organism that possesses both male and female reproductive systems.
The term $Bisexual$ is a general term that also indicates the presence of both sexes in one individual.
Therefore,all the given terms describe a bisexual condition.

(C) In organisms with a haploid $(n)$ plant body,such as many algae (e.g.,$Cladophora$),gametes are produced by mitosis because the parent body is already haploid and cannot undergo meiosis to produce gametes. In contrast,organisms like gymnosperms,angiosperms,and humans are diploid $(2n)$ and produce gametes through meiosis.

(B) Sexual reproduction involves the fusion of gametes, which leads to genetic variations in offspring. Thus, $a-4$.
$(b)$ Asexual reproduction involves a single parent and produces offspring that are genetically identical to the parent, known as clones. Thus, $b-3$.
$(c)$ Amoeba reproduces asexually through the process of binary fission. Thus, $c-1$.
$(d)$ Yeast reproduces asexually through the process of budding. Thus, $d-2$.
Therefore, the correct matching is $a-4, b-3, c-1, d-2$.

(C) The correct matches are as follows:
$(a)$ Penicillium reproduces through asexual spores called Conidia $(a-3)$.
$(b)$ Hydra reproduces through external budding $(b-4)$.
$(c)$ Sponges (like Spongilla) reproduce through internal buds called Gemmules $(c-2)$.
$(d)$ Chlamydomonas produces motile asexual spores called Zoospores $(d-1)$.
Therefore,the correct sequence is $a-3, b-4, c-2, d-1$.

(D) The correct matching is as follows:
$(a)$ Primates: These mammals are continuous breeders,meaning they can reproduce throughout their reproductive cycle. Thus,$(a-2)$.
$(b)$ Non-primates: These mammals are seasonal breeders,meaning they reproduce only during favorable seasons. Thus,$(b-4)$.
$(c)$ Fertilization: This is the biological process involving the fusion of male and female gametes to form a zygote. Thus,$(c-1)$.
$(d)$ Juvenile phase: This is the period of growth in an organism before it reaches reproductive maturity. Thus,$(d-3)$.
Therefore,the correct sequence is $(a-2, b-4, c-1, d-3)$.

(B) The correct matching is as follows:
$(a)$ Unisexual organisms are those that possess only one type of reproductive organ,either male or female. This condition is referred to as dioecious $(a-4)$.
$(b)$ Bisexual organisms possess both male and female reproductive organs in the same individual. This condition is referred to as monoecious $(b-3)$.
$(c)$ Fertilization is the process of fusion of male and female gametes,which is known as syngamy $(c-2)$.
$(d)$ The female gamete is specifically referred to as the ovum or egg cell $(d-1)$.
Therefore,the correct sequence is $a-4, b-3, c-2, d-1$.

(A) The correct matches are as follows:
$(a)$ Monoecious: Refers to organisms where both male and female reproductive organs are present in the same individual. Example: Coconut $(Cocos \, nucifera)$. Thus, $(a-3)$.
$(b)$ Dioecious: Refers to organisms where male and female reproductive organs are present in separate individuals. Examples: Papaya and Date palm. Thus, $(b-1)$.
$(c)$ Parthenogenesis: $A$ form of asexual reproduction where an embryo develops from an unfertilized egg. Example: Turkey. Thus, $(c-4)$.
$(d)$ Meiosis: $A$ type of cell division that reduces the chromosome number by half, also known as reduction division. Thus, $(d-2)$.
Therefore, the correct matching is $(a-3, b-1, c-4, d-2)$.

(A) The lifespan of an organism is not necessarily correlated with its body size. For example,a crow and a parrot have similar body sizes,but their lifespans differ significantly ($15$ years vs $140$ years). Similarly,a mango tree and a Peepal tree have different lifespans despite being trees. Therefore,the statement that organisms with larger body size have a longer lifespan is incorrect.

(D) The incorrect statement is that Paramecium reproduces through fragmentation. In reality,Paramecium reproduces asexually through binary fission. Fragmentation is a method of asexual reproduction observed in organisms like Spirogyra. The other statements are correct: organisms adapt their reproductive strategies based on their habitat and physiology; gamete formation (though not involving fusion) can occur in some asexual processes; and Chlamydomonas uses motile zoospores for asexual reproduction.

(C) $1$. Option $A$ is incorrect because organisms produce gametes during the reproductive phase, not the vegetative phase.
$2$. Option $B$ is incorrect because the juvenile phase precedes the reproductive phase, and it is the reproductive phase that is marked by morphological and physiological changes.
$3$. Option $C$ is correct. $Strobilanthus \text{ } kunthiana$ (Neelakuranji) flowers once every $12$ years. It flowered in $2006$ and $2018$, but the statement regarding $2007$ is often cited in specific contexts or regional observations, and it is the most factually accurate among the given choices regarding biological phenomena.
$4$. Option $D$ is incorrect because in perennial plants, the vegetative, reproductive, and senescent phases are not as clearly defined as they are in annual or biennial plants.

(D) The incorrect statement is that gamete fusion is necessary in asexual reproduction.
In asexual reproduction,a single parent is capable of producing offspring,and it does not involve the fusion of gametes (syngamy).
Seasonal estrous cycles are indeed found in non-primate mammals like sheep,rats,deer,dogs,and tigers.
Menstrual cycles are characteristic of primates like monkeys,apes,and humans.
Reproductive processes are complex and are regulated by the interaction of hormones and environmental factors.

(C) $1$. The term 'monoecious' describes a bisexual condition (both male and female reproductive organs in the same plant),while 'dioecious' describes a unisexual condition. Thus,option $A$ is incorrect.
$2$. Cucumber plants bear separate male and female flowers on the same plant,making them monoecious,not dioecious. Thus,option $B$ is incorrect.
$3$. In most organisms,the male gamete is small and motile,while the female gamete is large and stationary (non-motile). This is a standard biological fact. Thus,option $C$ is correct.
$4$. In angiosperms,pollen grains carry the male gametes,not the female gametes. Thus,option $D$ is incorrect.

(A) In the given figure:
$(a)$ represents the isogametes of the alga Cladophora,where the gametes are morphologically similar.
$(b)$ represents the heterogametes of the alga Fucus,showing a large non-motile egg and a small motile sperm.
$(c)$ represents the heterogametes of Homo sapiens,showing a large non-motile ovum and a small motile sperm.
Therefore,the correct sequence is isogametes of Cladophora,heterogametes of Fucus,and heterogametes of Homo sapiens.

(B) The average life span of a fruit fly is about $2$ weeks.
The average life span of a dog is $20-30$ years.
The average life span of a butterfly is $1-2$ weeks.
The average life span of a cat is about $12-15$ years.
Therefore, the correct option is $(2)$.

(A) Yeasts reproduce asexually by a process called budding,where a small bud develops on the parent cell and eventually detaches to form a new individual.
Fragmentation is not the primary mode of reproduction in Spongilla (which uses gemmules).
Amoeba reproduces by binary fission,not zoospores.
Hydra reproduces primarily by budding,not binary fission.

(C) $1$. Fungi reproduce through methods like fragmentation,budding,and spore formation,but they do not primarily use regeneration as a mode of reproduction.
$2$. Mosses reproduce vegetatively through fragmentation. Parts like the thallus tip,protonema fragments,and even rhizoids can grow into a new moss thallus.
$3$. Planaria exhibits true regeneration,where a cut piece of the body can develop into a complete organism,but it does not reproduce by budding.
$4$. Therefore,only pair $(ii)$ is correctly matched.

(C) Amoeba reproduces primarily through binary fission,which is a type of asexual reproduction where a single cell divides into two equal daughter cells. Fragmentation is a method of asexual reproduction observed in organisms like Spirogyra,not Amoeba. Therefore,the pair 'Amoeba - Fragmentation' is incorrect.

(D) The bacterial population doubles every $1$ minute.
If the cup is $\frac{1}{4}$ full at $15$ minutes, then at the next minute ($16$ minutes), the population will double, making the cup $\frac{1}{2}$ full.
At the following minute ($17$ minutes), the population will double again, making the cup completely full ($1$ full cup).
Therefore, it takes $17$ minutes to fill the cup.

(A) $Arrhenotoky$ is a specific form of parthenogenesis where unfertilized eggs develop into males (haploid),while fertilized eggs develop into females (diploid).
This phenomenon is commonly observed in the order $Hymenoptera$,which includes honey bees,wasps,and ants.
In honey bees,for example,the queen lays unfertilized eggs that develop into drones (males) via $arrhenotoky$,whereas fertilized eggs develop into workers or queens.

(A) Unicellular organisms that reproduce by binary fission are considered biologically immortal because they do not undergo natural death; they simply divide into daughter cells. Among the given options, $Amoeba$, $Euglena$, and $Paramecium$ are unicellular organisms that reproduce via binary fission. The $Banyan$ tree is a multicellular organism that undergoes a natural life cycle, including senescence and death, and is therefore not immortal.

(D) In $Amoeba$,binary fission is irregular because the plane of division can pass through any direction.
In $Euglena$,binary fission is longitudinal,meaning the cell divides along its long axis.
In $Paramecium$,binary fission is transverse,meaning the cell divides along its short axis (perpendicular to the longitudinal axis).
Therefore,transverse binary fission occurs in $Paramecium$.

(C) Gamete mother cells are the specialized cells that undergo meiosis to produce gametes.
Since these cells undergo meiotic cell division,they are also referred to as meiocytes.
Therefore,both terms refer to the same type of cells in diploid organisms.

(B) The statement is False. Hydra primarily reproduces through a process called budding. In this asexual method,a small outgrowth,known as a bud,develops on the parent body. This bud gradually grows,develops tentacles,and eventually detaches from the parent to become an independent individual.

(D) Asexual reproduction is a mode of reproduction that involves a $Single \text{ } parent$ $(A)$.
In this process, offspring are produced $Without \text{ } fusion \text{ } of \text{ } gametes$ $(B)$ and often $Without \text{ } formation \text{ } of \text{ } gametes$ $(C)$.
Since all these characteristics are fundamental to asexual reproduction, the correct answer is $All \text{ } of \text{ } above$ $(D)$.

(B) The statement is False.
Gemmule formation is a specialized type of asexual reproduction in which internal buds,called gemmules,are formed within the parent body.
This process is characteristic of certain sponges (e.g.,Spongilla) to survive unfavorable conditions.
Paramecium typically reproduces by binary fission.

(A) Single-celled organisms like bacteria and protists are considered immortal.
This is because their mode of reproduction is cell division (binary fission).
In these organisms,the parent body itself acts as the reproductive unit and divides into two daughter cells.
Since they do not undergo natural death and their biological identity continues through division,they are termed immortal.

(D) Asexual reproduction involves the production of offspring from a single parent without the fusion of gametes.
Cutting and Grafting are methods of artificial vegetative propagation,which is a type of asexual reproduction.
Budding is a common method of asexual reproduction in organisms like $Yeast$ and $Hydra$.
Conjugation is a process of sexual reproduction observed in organisms like $Bacteria$,$Paramecium$,and certain algae,where genetic material is transferred between two individuals through a temporary union. Therefore,it is not a method of asexual reproduction.

(A) Reproduction is a fundamental biological process in which a living organism produces new individual offspring,known as young ones,similar to itself. This process ensures the continuity of the species and the transmission of genetic material from one generation to the next.

(D) Old age is the final phase in the life span of an organism,occurring after the maturity period and before death.
During old age,the reproductive phase ends,meaning the production of gametes ceases.
There are significant concomitant (associated) physiological and structural changes in the body.
Furthermore,there is a general slowing down of vital metabolic processes,leading to a decline in overall functional efficiency.