BIOLOGY

PRESENTATIO

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Twins are two offspring resulting from the same pregnancy, usually born in close succession.

They can be the same or different sex.

What are Twins?

Identical Twins

Fraternal Twins

Conjoined Twins

Types of Twins

As off springs reproduced by fertilization.

The fertilized egg now called zygote divides one time, resulting into two cells.

By the sixth day after fertilization, the zygote implants itself in the uterine wall & continues to develop for nine months.

After implantation the baby is called an embryo.

Around week nine of development it is called a fetus.

Now Twins are formed.

Stages of Twin Formation

CLONING

Cloning is the process of producing similar populations of genetically identical individuals that occurs in nature when organisms such as bacteria, insects or plants reproduce asexually.

Cloning in biotechnology refers to processes used to create copies of DNA fragments.

What is Cloning?

DNA cloning or molecular cloning refers to the process in which DNA fragments are transferred of interest from one organism to a self-replicating genetic element such as a bacterial plasmid. The DNA of interest can then be propagated in a foreign host cell. This technology has become common practice in molecular biology labs even today.

DNA Cloning

Reproductive cloning is a technology used to generate an animal that has the same nuclear DNA as another currently or previously existing animal. This process was the one used to create Dolly. This process is called somatic cell nuclear transfer or SCNT.

Reproductive Cloning

ASEXUAL

REPRODUCTION

Asexual reproduction is a mode of reproduction by which offspring arise from a single parent, and inherit the genes of that parent only.

What is Asexual Reproduction?

It is the simplest and most common method of asexual reproduction. The whole parental body acts as the reproductive unit. The nucleus of the unicellular parent organism divides into two. This is followed by the division of the cytoplasm and 2 daughter cells of almost equal size are formed. The daughter cells grow in size and then divide again.

Binary Fission

In some organisms the nucleus of the parent divides into many daughter nuclei by repeated divisions (amitosis). This is followed by the division of the cytoplasm into several parts with each part enclosing one nucleus. So a number of daughter cells are formed from a single parent at the same time. This kind of fission is known as multiple fission.

Multiple Fission

 A new organism develops from an outgrowth or bud on another one. The new organism remains attached as it grows, separating from the parent organism only when it is mature, leaving behind scar tissue. Since the reproduction is asexual, the newly created organism is a clone and is genetically identical to the parent organism.

Budding

In some organisms the body of the organism breaks into several parts. Each part then develops into a complete organism.

Fragmentation

Made By-

Abhinav SomaniVIII-B