EMBRYOGENESIS 
● the process of development of embryo from the zygote.
● During this, zygote undergoes mitotic division and cell differentiation.
● Cell division increase the number and cell differentiation help in formation of new group of cells and organs.
OVIPAROUS
★Development of zygote takes place outside the body of organisms and lay fertilized of unfertilized eggs.
Ex - Reptiles and birds
DIFFERENT PHASES IN SEXUAL REPRODUCTION
★[A]★ JUVENILE PHASE
★The period between birth and sexual maturity is called juvenile phase.
★In plants it is known as vegetative phase.The end of juvenile/vegetative phase marks the beginning of the reproductive phase.
[B]REPRODUCTIVE PHASE
● Some plants show flowering in particular season and some other flowers in all seasons.
●Some other plants like bamboo species flowers once in life time (after 50-100 years),
●Strobilanthus kunthiana (neelakuranji), flowers once in 12 years.
●The female placental animals exhibit cyclic change in activities ovaries and accessary glands as well as hormone during the reproductive phase.
SEXUAL REPRODUCTION
●Involves formation of male and female gamete by two individuals of the opposite gender
●Offspring produced by fusion of male and female gametes not identical to each other or to the parents.
●All sexually reproducing organisms share a similar pattern of reproduction.
●In sexual reproduction, fusion of male and female gametes results in offspring that are not identical to parents.
EXTERNAL FERTILIZATION
★Syngamy occurs outside the body of the organism Large numbers of
gametes are released in the
surrounding medium.
★Ex. Bony fishes and Amphibians.
INTERNAL FERTILIZATION
★Syngamy occurs inside the body of the organism Numbers of ova produced are less, but large numbers
of male gametes are released and they travel towards
the ovum.
Ex. Birds and Mammals.
GAMETE TRANSFER
●In majority of organisms, male gametes are motile and females
gametes are non-motile, except in fungi and algae in which both gametes are motile.
● In simple plants like algae, fungi, bryophytes and pteridophytes water is the medium through which male and female gametes moves.
●The number of male gametes are much more than number of female gametes as most of male gametes fail to reach the female gametes.
● In higher plants pollen grains are carrier of male gametes and ovule has eggs.
● Pollen grains must be transferred from anther to stigma to facilitate fertilisation.
● The transfer of pollen
grains from anther to stigma is called pollination.
★Pollination may be self (anther to stigma of same flower) or cross (anther to stigma of different flower).
★Pollen grains germinate on stigma to produce pollen tube that delivers the male gametes near the ovule.
■FERTILISATION ■– The fusion of male and female gamete is called fertilization or syngamy.
★It results in the formation of diploid zygote.
★The process of development of new organisms without fertilisation of female gametes is called parthenogenesis.
★ For example honey bee, rotifers, and lizards
OESTROUS CYCLE
︎It occurs in non primates like cow, sheep, rat, deer, dog, tiger etc.
︎ It consists of a short period of oestrous or heat. it is 12-24 hours in cow followed by anoestrous or passive period.
︎Blood does not flow in this cycle. The broken endometrium is reabsorbed.
︎ Female permits copulation only during oestrous period.
︎Both in plants and animals, hormones are responsible for the transition between different
phases of life cycle.
★Interaction between hormones and environmental factors regulate the
reproductive processes.
MENSTRUAL CYCLE
︎ It occurs in monkeys, apes and human beings.
︎ Cycle consists of 3 phases-menstrual, proliferative and secretory phase.
︎Blood flows in the last few days of the cycle. The broken endometrium is passed out during
menstruation.
︎Female does not permit copulation during menstrual phase of the cycle.
WATER HYACINTH
☆ (Terror of Bengal)
★One of the most invasive weeds
Grows wherever there is standing water Drains oxygen from water- leads to death of fishes.
☆Introduced in India because of its pretty flowers & shape of leaves
Vegetative propagation occurs at a phenomenal rate
●Asexual reproduction is the most common method of reproduction in organisms having simpler body like in algae and fungi but during unfavorable condition they shift to sexual
reproduction.
EVENTS IN SEXUAL REPRODUCTION
★Pre-fertilisation
★Fertilisation
★Post-fertilisation
PRE-FERTILISATION
★all the events prior to fusion of gametes are included in it.
★It includes gametogenesis and gamete transfer.
★[A]★ Gametogenesis is the process of formation of male and female gametes.
☆Gametes are haploid cells which may be similar or dissimilar in structure.
★In algae, both gametes are
similar in structure called homogametes (isogametes).
★In higher organism that reproduces
sexually, two morphologically distinct gametes are formed called heterogametes,
︎ male gametes are called antherozoid or sperm and
︎female gametes are called ovum or egg.
★ heterogametes
In fungi and plants,
★homothallic and monoecious terms are used to denote the bisexual
condition and heterothallic
★dioecious are used for unisexual condition. In flowering
plants,
︎the unisexual male flower is staminate, i.e., bearing stamens,
︎while the female is
pistillate or bearing pistils.
★In animals, species which possess both male and female reproductive organs in same individual are called bisexual or hermaphrodites (earthworm, sponges, tapeworm etc.)
★both having either male or female reproductive organs are called unisexual (cockroach,
human).
★Gametes are always haploid( having half set of chromosome ), although organisms may be haploid and diploid.
★Diploid organisms form gametes by meiotic division.
●The organisms
belonging to algae, fungi, and bryophytes have haploid plant body
● pteridophytes, gymnosperms, angiosperms and most of animals are diploid ( having double set of
chromosome )
★ In diploid organisms, gamete mother cell (meiocyte) undergoes meiosis in which one set of
chromosome is present in gametes
★➢ Tissue – group of cells having a common origin and usually performing a common function
☆➢ Two groups of plant tissue
★➢ meristems – Growth in plants is largely restricted to specialised regions of active cell division
☆- apical meristems – occur at the tips of roots and shoots and produce primary tissues
★➔ shoot apical – meristem occupies the distant most region of the stem axis
★➔ root apical – occupies the tip of a root
★➢ permanent or mature cells – newly formed cells become structurally and functionally
specialised and lose the ability to divide, constitute Primary tissue
Properties of monosaccharide
(a) Monosaccharides are colourless, sweet tasting, solids.
(b) Due to asymmetric carbon, they exist in different isomeric forms. They can rotate polarized light hence they are dextrorotatory and leavorotatory.
(c) D-glucose after reduction gives rise to a mixture of polyhydroxy alcohol, sorbitol or mannitol.
(d) The sugars with a free aldehyde or ketone group reduce Cu++ to Cu+ (cupric to cuprous)
(e) Sugars show oxidation, esterification and fermentation.
(f) The aldehyde or ketone group of a simple sugar can join an alcoholic group of another organic compound bond C-O-C the process involves loss of water and is called condensation (H-O-H) or H+OH → H2O.
NITROGEN role and deficiency symptoms
Impart green colour to plant encourages vegetative growth
Nitrogen is essential constituent of protein
Constituent of Protoplasm of chlorophyll and coenzyme.
Play important role in
synthesis of auxin
#Deficiency
Lower leaves become yellow and dries.
V shaped chlorosis on older leaves or yellowing at tip.
#Disease
Starvation disease due to nitrogen deficiency.
Buttoning in cauliflower.
Phosphorus functions and deficiency symptoms
Increase the disease resistance.
Enhance new cell formation and necessary for root development.
Required for grain formation and maturity of grains.
Phosphorus is essential constituent for nucleic acid and phytin.
Most essential functions are energy storage and transfer energy act as “energy currency”.
#Deficiency
Due to deficiency of single element the life cycle of plant can’t be completed hence (Agricultureexamslibrary) Phosphorus is called " key of life "
Deficiency imparts dark green colour in leaves.
Later develops red purple colourration.
#Disease
Sickle leaf diseases.
Pottasium deficiency symptoms and role
Most essential function of K+ is stomata regulation.
Provides disease resistance in plants.
Cofactor for enzymes.
Formation and translocation of Sugars.
Helps in chlorophyll formation.
#Deficiency
Spot of dead tissue at tips.
Scorching and burning on margins of autumn leaves.
#Disease
Rottle/ dieback disease.
Calcium role and deficiency symptoms
Calcium
It is constituent of cell wall
Calcium is a mobile in plants and deficiency symptoms appear on Meristem tip portion.
Terminal bud die
#Disease
Tip hooking.
Blossom end rot of tomato(BER).
Popping in groundnut.
Sulphur and magnesium role and important functions
Magnesium
Essential constituent of chlorophyll.
Magnesium is a constituent of chlorophyll.
Chlorosis between veins.
#Disease
Sand -drown disease of tobacco.
#Sulphur
Sulphur oxidizing Bacteria is Thiobacillus.
Sulphur is essential for oil seed and pulses because it improves oil content and protein content in oil seeds and pulses, respectively.
#Disease
Akiochi disease of rice due to Excess of hydrogen sulphide.
Tea yellow disease of tea.
Iron and manganese role and deficiency
Iron
Fe is the component of nitrate reductase.
Required for nitrogen fixation.
During respiration act as O2 carrier.
#Deficiency
Interveinal complete chlorosis.
Scorching of leaf margin.
Yellowing of iron chlorosis in groundnut.
#Manganese
Formation of chlorophyll.
Co-factor of enzyme.
Mn toxicity causes crinckle leaf of cotton.
#Deficiency
Dead spot on leaves.
#Desease
Marsh spot of pea.
Pahala blight of sugarcane.
