REPRODUCTION

Reproduction is the capacity of all living things to give rise to new living things. It includes the transmission of hereditary material from the parent/parents.

The two types of reproduction are: Asexual Reproduction Sexual Reproduction

ASEXUAL REPRODUCTION

Is the simplest form of reproduction. Occurs in plants, animals, bacteria, and protists Requires one parent. Is more reliable than sexual reproduction. Doesn’t allow for any type of genetic variation.

TYPES

Sporulation Fragmentation Regeneration Binary Fission Budding Vegetative propagation

SPORULATION

Spore is a reproductive cell that produces a new organism.

Spores are unicellular if conditions are right a spore will develop into a new individual.

They can be carried by the wind, water, or animals

FRAGMENTATION

When a organism is broken into more than one part.

Organism must have good regeneration abilities.

Create many new organisms quickly.

REGENERATION An organism can replace/re-grow an injured or

lost part Regeneration in plants from Roots Stem leaf Regeneration in animals For simple organisms No vertebrates have this power Examples are starfish and the salamander

BINARY FISSION

One parent dividing into two by mitosis Offspring are always genetically identical Cells may stay close together to form

filaments or colonies Examples-Bacteria and Amoebas

BUDDING

Form on part of the parent by growing an outgrowth which then detaches

Example- is Hydra and Yeast Offspring will always be genetically identical to

the parent

VEGETATIVE PROPOGATION

Plant parts make new plant Reproduction is very quick Disadvantage: many plants grow close to each

other

Bulbs – Underground stem – Surrounded by colorless leaves – Colorless leaves protect the bulb – The green leaves store the food Rhizomes – Underground stem – They store food for new plant – At the end of Rhizomes nodes

Runners(strawberries) – They are above ground. – Stems – Nodes form at the end of Runners – They grow outward Tuber (potatoes) – Underground stem – Stores food – The nodes eat the tuber – Potatoes have eyes / buds to make new

tubers and or reproduce

Grafting – Surgically connecting two similar plants – Ex. Apples – Not done naturally Cutting – Cutting off a stem or leaf to reproduce a

new plant – Must be in wet or moist area – Combination of regeneration and

fragmentation – Not done naturally

Cloning

WHAT IS CLONING?

Cloning is the creation of an organism that is an exact genetic copy of another. This means that every single bit of DNA is the same between the two!

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How does one go about making an exact genetic copy of an organism? There are a couple of ways to do this: artificial embryo twinning and somatic cell

nuclear transfer.

HOW IS REPRODUCTIVE CLONING DONE?

ARTIFICIAL EMBRYO TWINNING IS THE RELATIVELY LOW-TECH VERSION OF CLONING. AS THE NAME SUGGESTS, THIS TECHNOLOGY MIMICS THE NATURAL PROCESS OF CREATING IDENTICAL TWINS.

Artificial Embryo Twinning

DNA cloning or Gene cloning

A clone has been made from this technique.

DNA fragment is transferred to self-replicating element

Used to generate multiple copies of the same gene

Human Genome Project Study

Bacterial Plasmid1804/14/2023

DNA cloning or Gene cloning

Advantages1/ Potential benefits to modern medicine

2/ Helping in fertile couples

3/ Reverse the aging process

4/ Protecting Endangered Species

Disadvantages

1/ The Element of Uncertainty

2/ Inheriting diseases

3/ The Potential for Abuse

Dolly the sheep

Dolly (1996-07-05– 2003-02-14, a ewe, was the first mammal to have been successfully cloned from an adult cell (while the mice in USSR

were cloned from embryo cell back in 1986). She was cloned at the

Roslyn Institute in the United Kingdom and lived there until her death when she was 6. Her birth was announced on 1997-02-22.

Dolly and her first-born lamb, Bonnie

Twins

WHAT ARE TWINS?

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

They can be the same or different sex.

TYPES OF TWINS

IDENTICAL TWINS FRATERNAL TWINS CONJOINED TWINS

STAGES OF TWIN FORMATION

• As off springs reproduced by fertilization. • the fertilized egg, now called a zygote divides one

time, resulting in two cells.• By the sixth day after fertilization, the zygote

implants itself in the uterine wall and continues to develop for nine months.

• after implantation, the developing baby is called an embryo.

• Around week nine of development, it is called a fetus • Now we know and twins are formed.

IDENTICAL TWINS

• Occur when a single egg is fertilized to form identical which then divides into two separate embryos.

• They have identical genes.

FRATERNAL TWINS• Usually occur when two fertilized eggs are

implanted in the uterine wall at the same time. When two eggs are independently fertilized by two different sperm cells.

• The two eggs form two zygotes.• They have same or opposite sex and they

don't have to look at all alike.• They have separate placentas

CONJOINED TWINS

• Conjoined twins are joined at some region of their bodies. The many different types of conjoined twins are classified by the area where the attachment is located.

Lavanya Topa (VIII-A)