BIOLOGY- 12 STD CBSE CHAPTER 1

REPRODUCTION IN ORGANISM

PART 1

• DEAR STUDENTS THIS IS THE FIRST LESSON IN 12 TH STD BIOLOGY READER.

• I HOPE YOU GO THROUGH THIS PPT AND UNDER STAND THIS SIMPLE LESSON

• AT THE END OF THE PPT THERE IS AN ASSIGNMENT TRY TO DO IT .

• I HAVE INCLUDED MANY PHOTOS AND A SMALL VIDEO

• THANK YOU, HOPE YOU ENJOY AND BE BENIFITTED.

BIOLOGY ACADEMIC SUPERVISOR

MRS.R.VIJAYALAKSHMI

REPRODUCTION IN

ORGANISM

LIFE SPAN: The period from birth to the natural death of an

organism

REPRODUCTION: A biological process in

which an organism gives rise to offspring similar to

itself

ASEXUAL REPRODUCTION: 1) offspring are produced by a single parent 2) gametes are not involved 3) offsprings are clones of each other and to their parent 4)common in simple organism (monera,protista)

CLONE: Morphologically and

genetically similar individuals

Cell division itself is a mode of reproduction in unicellular animals: Binary Fission: Amoeba Paramecium Budding : Yeast

BINNARY FISSION

• Binary Fission-Many single celled organisms reproduce by binary fission, where a cell divides in two halves and each rapidly -grows into adult.

• e.g. Amoeba, Paramecium.

Binary Fission In Amoeba Taken Under Microscope

BINARY FISSION IN AMOEBA

BINARY FISSION IN PARAMECIUM

BUDDING IN YEAST under microscope

BUDDING IN YEAST

Hydra Bud formation This Slide is a clear illustration of

asexual reproduction.

BUDDING IN HYDRA

BUDDING IN HYDRA

ASEXUAL REPRODUCTIVE STRUCTURES: ZOOSPORE :CHLAMYDOMONAS CONIDIA :PENICILLIUM BUDS :HYDRA GEMMULES :SPONGES

ZOOSPORE: Microscopic Motile Asexual Reproductive Structures Of Fungi And Lower plants (algae)

Zoospore production in chamydomonas

Asexual reproduction in Penicillium

• Penicillium is a ascomycetous fungi

• FUNGI REPRODUCE ASEXUALLY BY MEANS OF CONIDIA

• Conidia are asexually produced spores that are borne externally to the cells that produce them

PENCILLIUM

CONIDIA OF PENICILLIUM UNDER SCANNING MICROSCOPE

ASEXUAL REPRODUCTION IN SPONGE

• An asexually produced mass of cells, which are capable of developing into a new organism or into an adult freshwater sponge

is termed as a Gemmule. • They are small bud like cells, which are

formed by sponges to withstand unfavorable environmental conditions.

GEMMULES IN SPONGE

GEMMULES IN SPONGE

GEMMULE FORMATION IN SPONGE PHOTOGRAPH TAKEN UNDER MICROSCOPE

Methods of Asexual Reproduction: • Cell division as a method of asexual

reproduction in Protista and Monera.

1. Binary fission e.g. Amoeba, Paramecium.

2. Budding: e.g. yeast.

3. Other Asexual reproductive structures:

i) Zoospores: aquatic fungi, Chlamydomonas.

ii) Conidia: Penicillium.

iii) Bud: Hydra.

iv) Gemmules: Sponges.

ASSIGNMENT

Q. 1. What is life Span ?

Q. 2. Define reproduction.

Q. 3. Give two example which reproduce a sexually by binary fission.

Q. 4. Draw a labelled diagram of conidia of Penicillium.

Q. 5. Diagrammatically represent the asexual reproduction in yeast.

Q. 6. Diagrammatically represent the asexual reproduction in Amoeba .

Q.7. Define clone.

Q.8. Mention the difference between asexual and sexual reproduction.

Q.9 Name one fungi that reproduce by budding and conidia.

Q.10. Name an organism in which cell division itself is a mode of reproduction

Q.11. Name a algae that produces zoospores. Why are they called so?

Q.12. How do Penicillium reproduce asexually?

THANK YOU PART 2 WILL CONTINUE