How do organisms reproduce - PowerPoint Presentation

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How do organisms reproduce?

WHAT IS REPRODUCTION ?

SEXUAL REPRODUCTION

Reproduction in Flowering Plants

Reproduction in Human Beings

ASEXUAL REPRODUCTION

Fission

Fragmentation

Regeneration

Vegetative Propagation

Spore Formation

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DEOXYRIBO NUCLEIC ACID (DNA)

Also known as “Blue Print” and “Master Copy”

Present in chromosomes in the nucleus of a cellContains information for inheritance of features

Information source for making proteins

First reaction takes place and DNA gets duplicatedDNAs separate from each other and make 2 different cellsDNA copies generated will be similar, but may not be identical to the original

DNA DUPLICATION AND REPLICATION

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IMPORTANCE OF VARIATION

Variation is important for the survival of species as it allows some individuals to withstand and changes in the environment or niches

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IMPORTANCE OF DNA COPYING IN REPRODUCTION

DNA Copying means the production of an exact copy of the original . But the process of copying DNA will have some variation each time which leads to the stability of the population and formation of new species .

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WHAT IS REPRODUCTION ?

Reproduction is the process by which organisms generate new individuals of the same kind.

Reproduction is classified into 2 types;

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1.ASEXUAL REPRODUCTION

It is the process of formation of new individual from any specialized or unspecialized part of a single parent without fertilization.Asexual Reproduction is classified into 6 groups, they are;FissionFragmentation

RegenerationBuddingVegetative PropagationSpore formation

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It is the type of asexual reproduction in which the parent cell splits into two or more daughter cells. The division can take place in any plane.

BINARY FISSION IN AMOEBA

MULTIPLE FISSION IN PLASMODIUM

a) FISSION

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b) Fragmentation

It is the type of asexual reproduction in which the parent cell is simply breaks up into smaller pieces upon maturation.

Fragmentation in Spirogyra

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c) Regeneration

It is the type of asexual reproduction in which the parent cell cut or brake up into several pieces, and each piece will develop into a new individual.

Regeneration in Planaria

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d) Budding

It is the type of reproduction in which a bud develops as an outgrowth due to repeated cell division at one specific site and the bud will develop to a new individual, when fully mature and detach from the parent body.

Budding in Hydra

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e)

Vegetative Propagation

It is the type of asexual reproduction in which the plant parts like the root, stem and leaves develop into new plants.

Bryophyllum

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VEGETATIVE PROPAGATION(CHRYSANTHEMUM)

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VEGETATIVE PROPAGATION (PISTIA)

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VEGETATIVEV PROPAGATION (POTATO)

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f) Spore Formation

It is the type of asexual reproduction in which the spores in the sporangium will come out, when matured and each spore will develop into new individuals.

Spore Formation in Rhizopus

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2.SEXUAL REPRODUCTION

It is the mode of multiplication in which young ones are formed due to the process

of gamete formation.

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Flower is a reproductive unit of a plant Parts of a flower include sepals, petals, stamen and stigma (pistil)Pistil is the female reproductive part.Pistil consists of stigma, style and ovary

Stamen is the male reproductive partStamen consists of filament, anther and pollen FLOWER

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The plants developed by vegetative propagation are genetically similarPlants developed by vegetative propagation bear flowers and fruits earlier than those raised from seeds Hundreds of genetically similar plants can be propagated from a single parent plant The plants which don’t produce viable seeds can be propagated only by this method It needs lass attention than those raised from seeds

ADVANTAGES OF VEGETATIVE PROPAGATION

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L.S.OF A TYPICAL FLOWER

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POLLINATION (ENTEMOPHILY)

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POLLINATION

SELF POLLINATIONTransfer of pollen grains from anther to the stigma of the same flower CROSS POLLINATIONTransfer of pollen grains from anther to the stigma of another flower of the same plant or different plant of the same species

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PROCESS OF FERTILISATION IN PLANTS

In plants pollination is followed by fertilisationThe pollen grains deposited on the stigma germinated to form a pollen tube Simultaneously the nucleus present in the pollen grain divides in to two male gametesThe pollen g[tube bearing two male gametes penetrate through the style reaches the ovary and enter in to the embryo sac through the micropyle

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DOUBLE FERTILIZATION

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POST FERTILISATION CHANGES One of the male gamete fuses with the egg (ovum) to form a diploid zygote .this process of fertilization is called zyngamy

Another male gamete fuses with two polar nuclei to form a triploid PEN (primary endosperm nucleus) .This ferilisation is called triple fusion As two fertilisation takes place simultaneously in the embryo sac ,this process is called double

fertilisation.After fertilisation ,the zygote changes in to embryo and the PEN changes in to endosperm The endosperm provides nutrition to the developing embryo

After fertilisation , the sepals and petals fall off and the ovary changes in to fruit and the ovules changes in to seeds

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MALE REPRODUCTIVE SYSTEM

Male reproductive system consists of a pair of testes .the testes lie in a muscular bag called scrotum which lie outside the abdominal cavity .There is tubular structure arise from each testis and is called vas deferens. It unites with a duct arising from the urinary bladder and form a common tube called urethra. The urethra is enclosed within a muscular organ called penis Scrotum lie outside the abdominal cavity between two legs because the production of sperm requires a lower temperature (2—2.5 C less ) than the normal body temperature Functions of testes 1. production of sperms

2. secretion of male hormone testosterone

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Male Reproductive System

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Female reproductive system consists of a pair of ovaries which are located in the abdominal cavity near kidneys each ovary contains a large number of follicles which on maturation at puberty becomes eggs Near the posterior end of each kidney there is a funnel shaped structure called fallopian tube or oviduct . The fallopian tube opens in to the uterus .the uterus opens in to vagina through cervix Functions of ovary 1. production of egg or ovum

2. secretion of female hormone estrogenFEMALE REPRODUCTIVE SYSTEM

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Female Reproductive System

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.Seminal vesicle secretes an alkaline viscous liquid semen which provides nutrients to the sperm .Prostrate gland secretes a milky fluid which makes the sperms to transport faster Cowper’s gland secrets a fluid which acts as a lubricant

ACCESSORY GLANDS ASSOCIATED WITH THE MALE REPRODUCTINE SYSTEM

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Placenta is special disc shaped tissue found on the inner wall of the uterus . The embryo gets nutrients and oxygen from the mothers blood with the help of placenta through umbilical cord it also transport waste materials and carbon dioxide from the foetus

to the mothers blood ROLE OF PLACENTA

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The inner lining of the uterine wall slowly breaks and comes out through the vagina as blood and mucous known as menstruation It occurs every month and lasts for 2 to 5 days

WHAT HAPPENS IF FERTILISATION DOES NOT OCCUR

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1.Natural method2.Barrier method 3.Chemical method 4.Surgical method Natural methods –abstinence and withdrawal

Abstain from coitus from day 10 to 17 of the menstrual cycle Withdrawal of the penis from vagina before ejaculation Barrier method – in this method , physical devices such as condom , diaphragms, cervical ca[ps etc are used which prevents the entry of sperm in to the female genital tract during mating IUCD s such as loop and copper T are safely placed safely inside the uterus which prevent fertilization and implantation . the copper ions suppresses the mobility and fertilizing capacity of the sperms

DIFFERENT METHODS

OF CONTRACEPTION

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Chemical methods –use of oral or vaginal pills or chemicals that change the hormonal balance of the body so they prevent the ovulation and fertilization –

surgical methods – in this method a small portion of the vas deferens in males and fallopian tubes in females are surgically legated or tied .it is called vasectomy in males and tubectomy in females ‘It is an ideal method of contraception

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1.HIV—Human Immunodeficiency Virus2.AIDS---Acquired Immuno Deficiency Syndrome3.IUCD---Intra Uterine Contraceptive Device4.OC---Oral Contraceptive

5.STD---Sexually Transmitted Diseases6.STI---Sexually Transmitted Infections7.RTI---Reproductive Tract Infections8.ARSH---Adolescence Reproductive and Sexual HealthEXPAND

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PRESENTED BY,

P.V MANOHARANK.V NO 1 CPCRI KASARAGOD