Reproduction in Org NCERT Flashcards
When offspring is produced by a single parent with or without the involvement of gamete formation, the reproduction is _____________
asexual
Morphologically and genetically identical offsprings are also called
Clone
Among single celled organism and in plants and animals with relatively simple organisation the mode of reproduction is
Asexual reproduction
In _____________ and _____________, the organism or the parent cell divides by mitosis into two to give rise to new individuals
Protists & Monerans
Many single celled organisms reproduce by _______________, where a cell divides in two halves and each rapidly grows into adult.
Binary fission
The phenomenon of cyst formation is termed as
Encystation
When favorable conditions return, the encysted amoeba divides by-
Multiple fission
The encysted Amoeba divides by multiple fission and produces many minute amoeba or ______________.
Pseudopodiospores
The cyst wall bursts out, and the spores are liberated in the surrounding medium to grow up into many amoebae. This phenomenon is known as
Sporulation
Members of the Kingdom Fungi and simple plants such as algae reproduce through special ___________.
asexual reproductive structures
Members of the Kingdom Fungi and simple plants such as algae reproduce through special asexual reproductive structures. The most common of these structures are _________ .
Zoospores
____________ are usually a microscopic & motile structure
Zoospores
Name any three common asexual reproductive structures
Conidia, Buds and Gemmules
In plants, the units of _________________ such as runner, rhizome, sucker, tuber, offset, bulb are all capable of giving rise to new offspring
Vegetative propagation
In some organisms, if the body breaks into distinct pieces (fragments) each fragment grows into an adult capable of producing offspring. This is called
Fragmentation
Name the aquatic plant which is also known as the terror of Bengal
Water hyacinth
Adventitious buds arise from the notches present at margins of leaves of ______________
Bryophyllum
In animals, the ____________ phase is followed by morphological and physiological changes prior to active reproductive behaviour.
Juvenile phase
The juvenile phase is also known as
Vegetative phase
Name the plant which flowers once in 12 years
Strobilanthus kunthiana (neelakuranji)
In non-primate mammals like cows, sheep, rats, deers, dogs, tiger, etc., cyclical changes during reproduction are called
Oestrus cycle
The cyclic changes in primates like monkey, apes, and humans are called
Menstrual cycle
In sexual reproduction, fusion of gametes is termed as
Fertilization / syngamy
The events like fusion of gametes, the formation of zygote and embryogenesis are characteristics of_________
Sexual reproduction
Three stages of sexual reproduction are
Pre-fertilization, fertilization and post-fertilization events
________________ refers to the process of formation of the two types of gametes – male and female.
Gametogenesis
When both the gametes are similar in appearance that these can’t be distinguished, these gametes are called
Homogametes (isogametes)
Morphologically distinct types of gametes are called
Heterogametes
Male gametes are also called
Antherozoid or sperm
Female gamete is also called the ________
Egg or ovum
The fertilization of plants and some invertebrate animals by their own sperm rather than that of another individual is called
Self-fertilisation
Bisexual animals that possess both male and female reproductive organs are called ____.
Hermaphrodites
In several plants, the bisexual condition is denoted by _______________
Monoecious
The term used to describe the unisexual condition in plants is
Heterothallic
The term used for unisexuality in plants is
Heterothallic / Dioecious
The term used for unisexual male flower is
Staminate
______________ refers to having both the male and female reproductive organs on the same plant.
Monoecious
______________ refers to having both the male and female reproductive organs in the separate individuals.
Dioecious
Bisexual animals that possess both male and female reproductive organs, are _______________
Hermaphrodites
There are two types of gametes in all ______________ species
Heterogametic species
The plant body of several organisms belonging to Monera, fungi, algae, and bryophytes is __________ in nature.
Haploid
The reduction division has to occur if a __________ body has to produce haploid gametes
Diploid
In diploid organisms, specialised cells called ___________ undergo meiosis
Meiocytes
At the end of meiosis, only ___________________ gets incorporated into each __________
One set of chromosomes; gamete
After their formation, male and female gametes must be physically brought together to facilitate _____________
Fusion (fertilisation)
_____________ produced in anthers therefore, have to be transferred to the stigma before it can lead to fertilisation.
Pollen grains
In bisexual, self-fertilising plants, e.g., peas, transfer of pollen grains to the ___________ is relatively easy.
Stigma
A specialised event called______________ facilitates transfer of pollen grains to the stigma.
Pollination
_____________ results in the formation of a diploid zygote.
Syngamy
Syngamy results in the formation of a diploid ___________
Zygote
A natural form of asexual reproduction in which growth and development of embryos occur without fertilization by sperm is
Parthenogenesis
In many terrestrial organisms, syngamy occurs inside the body of the organism and the process is called
Internal fertilization
________________ refers to the process of development of embryo from the zygote
Embryogenesis
During embryogenesis zygote undergoes ________ and ________
Cell division and cell differentiation
An oviparous animal is one that produces______
eggs
_______________ animals give birth to their young ones.
Viviparous
In oviparous animals like reptiles and birds, the fertilised eggs covered by hard __________
Calcareous shell
The ovary develops into the fruit which develops a thick, protective wall called
Pericarp
The period from birth to the natural death of an organism represents its ___.
life span
___ is defined as a biological process in which an organism gives rise to young ones (offspring) similar to itself.
Reproduction
Life spans of organisms are not necessarily correlated with their _______.
Sizes
Crows and parrots are almost similar in ______
sizes
In yeast the division of cells is______
unequal
___________ are the mode of asexual reproduction in sponge.
gemmules
Crows and parrots show wide difference in their __________
lifespans
Between mango and peepal tree, which one lives longer?
Peepal tree
Except single celled organism, what is certain for every other living organism?
death
No individual is immortal, except __________
Single-celled organisms
The process in living organism that ensures continuity is___________
reproduction
Conidia are asexual reproductive structures found in_________.
Penicillium
Crow has a lifespan of ______
15 years
Crocodile has a lifespan of _____
60 years
Life span of parrot is ____
140 years
The life span of butterfly spans from ________
1 to 2 weeks
Tortoise usually have a long lifespan that can range from _____ to _______ years.
100 to 150
Reproduction is defined as a _________ process in which an organism gives rise to young ones (offspring) similar to itself.
biological
There is a cycle of _____, _________ and death.
birth, growth
Asexual reproductive structures found in chlamydomonas are __________.
zoospores
Reproduction enables the ________ of the species, generation after generation
continuity
Each organism has evolved its own mechanism to ________ and produce offspring.
multiply
Among an organism’s internal and external physiology, which one affects the reproduction?
Internal physiology
Which mode of reproduction produces offsprings identical to one another and also exact copies of their parent?
Asexual
Asexual reproductive structures found in Hydra are __________.
Buds
Asexual reproductive structures found in Pencillium are __________.
Conidia
Asexual reproductive structures found in sponge are __________.
Gemmules
Vegetative propagules found in potato are __________.
eyes
Vegetative propagules found in ginger are __________.
rhizome
Vegetative propagules found in agave are __________.
bulbil
Vegetative propagules found in bryophyllum are __________.
leaf buds
Vegetative propagules found in water hyacinth are __________.
offset
In animals and other simple organisms the term ______ is used unambiguously.
Asexual
What is the term used for asexual reproduction in plants?
Vegetative reproduction
The formation of vegetative propagules is _______ as it does not involve two parents.
asexual
Water hyacinth is found in standing or running water?
Standing water
Water hyacinth drains which gas from waters?
oxygen
Water hyacinth drains oxygen from water leading to death of _______.
fishes
It is difficult to get rid of water hyacinth as it can propagate at a phenomenal rate through ____________.
vegetative propagation
Name the plant which was introduced in India because of its beautiful flowers and shape of leaves but later turned invasive.
water hyacinth
Small plants can be seen emerging from which structure in potato?
eyes
Small plants emerge from the ________ of banana and ginger.
rhizomes
The site of origin of the new plantlets present in the modified stems of plants is ________.
nodes
Which structure after coming in contact with damp soil or water, produces roots and new plants?
nodes
Which organism exhibit both sexual and asexual mode of reproduction?
Algae and fungi
Algae and fungi shift to ________ method of reproduction just before the onset of adverse conditions.
sexual
Asexual (vegetative) as well as sexual modes of reproduction are exhibited by __________.
Higher plants
Which mode of reproduction is present in most of the animals?
Sexual
Sexual reproduction involves formation of the male and female gametes,either by the ____ individual or by ______ individuals of the opposite sex.
same, different
Gametes fuse to form the _____ which develops to form the new organism.
zygote
Which process results in formation of offspring that are not identical to the parents or amongst themselves?
sexual reproduction
Sexual reproduction is an ______, ________ and _______ process as compared to asexual reproduction
elaborate, complex, slow
Plants, animals or fungi share a similar pattern of __________ mode of reproduction.
sexual
Juvenile or vegetative phase are of ________ durations in different organisms.
different
The end of juvenile/vegetative phase marks the beginning of the _________ phase.
reproductive
Reproductive phase can be seen easily in the higher plants during ___________.
flowering
Plants –the _______and ______ types, show clear cut vegetative,reproductive and senescent phases.
annual, biennial
Vegetative, reproductive and senescent phases are very difficult to clearly define in ___________ plants.
perennial
_______ species flower only once in their life time.
Bamboo
Bamboo species flower only once in their life time, generally after how many years?
50-100 years
In animals, the juvenile phase is followed by __________ and _________ changes prior to active reproductive behaviour
morphological and physiological
The reproductive phase is also of ________ duration in different organisms.
variable
The females of _______ mammals exhibit cyclical changes in the activities of ovaries and accessory ducts as well as hormones during the reproductive phase
placental
Many mammals, especially those living in natural, wild conditions exhibit menstrual cycles only during favourable seasons in their reproductive phase and are therefore called _______________.
Seasonal breeders
Mammals that reproduce actively throughout their reproductive phase are called ___________ breeders.
continuous
The end of reproductive phase can be considered as one of the parameters of __________ or old age.
senescence
__________ ultimately leads to death.
Old age
In both plants and animals, __________ are responsible for the transitions between the three phases
hormones
Interaction between hormones and certain environmental factors regulate the _________ processes and the associated _______ expressions of organisms.
reproductive, behavioural
The events of sexual reproduction though elaborate and complex, follow a _______ sequence.
regular
The two main pre-fertilisation events are _______ and ________ transfer.
gametogenesis, gamete
Gametes are ______ cells
haploid
Which type of gametes are found in Cladophora (an alga)?
Isogametes
Type of gametes present in Fucus and Homo sapiens is ___________
Heterogametes
Heterogametes are found in majority of ________ reproducing organisms
sexually
The term used for unisexual female flower is
Pistillate
Cucurbits and coconuts are examples of _________ plants.
Monoecious
Earthworms, sponge, tapeworm and leech, typical examples of _______ animals
bisexual
Cockroach is an example of a _________ species.
unisexual
In organisms belonging to pteridophytes,gymnosperms, angiosperms and most of the animals including human beings, the parental body is ________.
diploid
Earthworm is a bisexual animal and cockroach is a _________ animal
unisexual
Male thallus in Marchantia contains _________ while female thallus contains __________.
Antheridiophore, Archegoniophore
Chara is _______ plant while Marchantia is _______ plant.
monoecious, dioecious
Female sex organ found in Chara is
oogonium
Male sex organ found in Chara is
antheridium
Sweet potato produces bisexual or unisexual flowers?
bisexual
If the ploidy level in gametes is ‘n’ then the ploidy level in meiocytes will be ______.
2n
Meiocytes are haploid or diploid?
diploid
Chromosome number in meiocytes of human is_____
46
Chromosome number in meiocytes of house fly is_____
12
Chromosome number in meiocytes of dog is_____
78
Chromosome number in gamete of cat is _____
19
Chromosome number in gamete of rat is _____
21
Chromosome number in meiocytes of fruit fly is ______
8
Chromosome number in gamete of Ophioglossum (a fern) is _____
630
Chromosome number in gamete of apple is _____
17
Chromosome number in meiocytes of rice is ______
24
Chromosome number in meiocytes of maize is ______
20
Chromosome number in gamete of potato is _____
24
Chromosome number in meiocytes of butterfly is ______
380
Chromosome number in meiocytes of onion is ______
16
In a majority of organisms, _______ gamete is motile and the _______gamete is stationary
male, female
Organisms in which both types of gametes are motile are few _______ and ______.
Fungi, algae
In several simple plants like algae, bryophytes and pteridophytes, _______is the medium through which this gamete transfer takes place.
water
The number of _____ gametes produced is several thousand times the number of ________ gametes produced.
male, female
Pollen grains germinate on the _______.
stigma
Successful _______ and coming together of gametes is essential for the most critical event in sexual reproduction, the ________.
transfer, fertilisation
The most vital event of sexual reproduction is perhaps the fusion of _______.
gametes
The terms syngamy and _______ are frequently used though , interchangeably
fertilisation
Development phenomenon taking place in some organisms like rotifers, honeybees and even some lizards and birds (turkey), is known as ____________.
Parthenogenesis
Which type of gametic fusion occurs in majority of algae and fishes as well as amphibians?
External fertilisation
Organisms exhibiting external fertilisation show great ______ between the sexes
synchrony
Release of large number of gametes into the surrounding medium (water) in order to enhance the chances of syngamy occurs in bony ______ and ________.
fishes, frogs
A major disadvantage of external fertilisation is that the offspring are extremely vulnerable to _________ threatening their survival up to ___________.
predators, adulthood
In organisms exhibiting internal fertilisation, the male gamete is ______ and has to reach the egg in order to fuse with it
motile
Internal fertilisation occurs in many terrestrial organisms, belonging to ______, higher animals such as ______, birds, mammals and in a majority of _______.
fungi, reptiles, plants
In the event of internal fertilisation the number of sperms produced is very large but there is a significant reduction in the number of ______ produced.
eggs
In seed plants, however, the__________ male gametes are carried to female gamete by pollen tubes.
non-motile
Events in sexual reproduction after the formation of zygote are called _________events.
post-fertilisation
Formation of the diploid zygote is universal in all ______ reproducing organisms.
sexually
In organisms exhibiting external fertilisation, zygote is formed in the external medium usually ______
water
In animals exhibiting ________ fertilisation, zygote is formed inside the body of the organism.
internal
Further development of the zygote depends on the type of ____________ the organism has and the ________ it is exposed to
lifecycle, environment
In organisms belonging to fungi and algae, zygote develops a thick wall that is resistant to _________ and damage.
dessication
In organisms with ______ life cycle, zygote divides by meiosis to form haploid spores that grow into _______ individuals.
haplontic, haploid
_______ is the vital link that ensures continuity of species between organisms of one generation and the next
Zygote
Every __________ reproducing organism, including human beings begin life as a single cell–the zygote.
sexually
Cell divisions increase the number of cells in the developing ________.
embryo
Cell ________ helps groups of cells to undergo certain modifications to form specialised tissues and organs to form an organism.
differentiation
Oviparous animals lay _______/_______ eggs.
fertilised/unfertilised
In oviparous animals like reptiles and birds,young ones hatch out after a period of ___________.
incubation
In viviparous animals (majority of mammals including human beings), the zygote develops into a young one inside the body of the ______ organism
female
After attaining a certain stage of _______,the young ones are delivered out of the body of the female organism.
growth
Because of proper embryonic care and protection, the chances of survival of young ones is greater in _________ organisms.
viviparous
In flowering plants, the zygote is formed inside the _______.
ovule
After fertilisation what parts of the flower wither and fall off?
sepals, petals and stamens
Generally even after fertilisation the _____ remains attached to the plant.
pistil
Following fertilisation, which structure develops in to embryo?
zygote
After fertilization, the ovules develop into ____.
seed
The ovary develops into the_______ which develops a thick wall called __________.
fruit, pericarp
What is the function of pericarp?
protection
After dispersal, seeds germinate under _______ conditions to produce new plants.
favourable
