Edgar Allan Poe

What is reproduction?

is the process by which new organisms are generated. It is the mechanism of species continuation. There are two means of reproducing: asexual and sexual reproduction.
Ex:
When two lions mate, they produce lion cubs as offspring. A bee carrying pollen from one daisy to another fertilizes it, causing it to reproduce in the form of fertilized seeds. In these and allother examples of reproduction, new individuals are created from existing ones.



Types of reproduction.

Two fundamental types may be distinguished; asexual reproduction, in which a single organism separates into two or more equal or unequal parts; and sexual reproduction, in which a pair of specialized reproductive (sex) cells fuse.
Sexual reproduction| Asexual reproduction |
the reproduction process in which male sex cells (sperm) fertilize female sex cells (egg). | The reproduction process in which sex cells are not involved at all.It’s when offspring are produced through platelets, tubers, runners, etc. |
There are two parents involved. | There is only on parent involved. |
| |

Plant Reproduction
Sexual Plant Reproduction
Mostplants need both male and female parts to reproduce. In most cases, a plant will need the pollen from the male part of a plant to come in contact with the eggs contained inside the female part of a plant.
* The male part of the plant is called the stamen and the female part is called the pistil.
* Some species of plants contain both male and female parts on the same plant, while othersmay require cross-pollination from other plants, or plants of a similar but not identical variety.

Asexual Plant Reproduction
Some plants are capable of reproducing on its own, without needing pollinating.
* Some plants can reproduce from a cutting that is taken and placed in water or moist soil, forming new roots from the cutting that will become a whole, self-sustaining plant.
*Other plants can reproduce by sending out rhizomes, or offshoots that form roots and become independent plants. Strawberries are good examples of this type of asexual reproduction.
* Some plants can form new bulbs, like tulips, without needing to produce seeds first
* .
Phenotypes and Genotypes
* An individual’s genotype is considered to be all of the combined genes that the organismcontains on it’s chromosomes.
* Not all of the genes that make up an organism’s genotype are known just by looking at physical characteristics, or traits, as many genes are not expressed or are silent in one way or another. The physical traits that are observable make up an organism’s phenotype.
* Phenotype = physically observable, Genotype = genetically determined

An organism’sphenotype can be influenced by it’s genotype, as is seen in this picture of a cat with a gene for normal ear shape (left) and a cat with a gene for curled ear shape (right).

Mendel's Law of Segregation The law says that alleles segregate (separate from each other) at some point before the formation of gametes, and are combined randomly at fertilization.
An example: The seeds of a garden pea maybe round or wrinkled. Round shape is determined by a gene G, and wrinkled shape by g. When Mendel crossed F1 plants (Gg) he found that, although all the parents had round seeds, about one-quarter of their offspring had wrinkled seeds.

Male and Female human reproductive system
When girls and boys reach puberty, their bodies start to change and become more mature. From this time, if a male anda female have sexual intercourse. It is possible that the girl could get pregnant, and a baby could start to grow.

Sperm is the male reproductive cell; the male gamete. Sperms cells fertilize a female egg cell in sexual reproduction.

An ovum is an unfertilized egg, or female gamete.In fertilization, a sperm cell unites with an ovum to produce a zygote.
Humans, like other organisms,...