Reproduction is the type of biological process in all living organisms that permits the living organisms of a species to produce progenies and transmits the genetic information from one generation to another generation. In this way, reproduction helps the organisms to perpetuate the races to survive on the planet.
Reproduction is of two types; asexual reproduction and sexual reproduction. In asexual reproduction, offspring are produced by a single organism or parent. It does not require any interaction or mating between two organisms of the same species and lacks the gamete formation, zygote formation, or fusion of gametes. In asexual reproduction, offspring receive genetic information from the parents through mitosis. So, this is the process of making clones of parent organisms. Offspring produced by this type of reproduction are genetically identical to the single parent. It takes place in lower organisms.
In sexual reproduction, offspring are produced by the two parents of separate sexes; male and female. Parents pass their genetic information to the offspring. The new progeny produced by sexual reproduction is a combination of both parents as it inherits half of the genetic information from the father and half from the mother. This type of reproduction usually occurs in higher organisms like vertebrates and higher invertebrates.
|Basis for Comparison||Asexual Reproduction||Sexual Reproduction|
|Definition||Asexual reproduction is the reproduction in which the fusion of gametes or change in the number of chromosomes does not occur.||Sexual reproduction is the reproduction in which zygote formation from gametes fusion and fertilization occurs.|
|No. of organisms involved||One parent||Two parents are required to mate|
|Cell division||Fission, budding or regeneration||Meiosis|
|Involvement of sex cells||No formation or fusion of gametes||Formation and fusion of gametes occur|
|Found in||Lower organisms||Higher invertebrates and in all vertebrates|
|Unit of Reproduction||The whole parent body, a bud, a fragment or a single somatic cell||Gamete|
|Time of completion||A short period||Several months|
|Number of offspring||Two or more||One or more|
Budding, fission and fragmentation
|Syngamy and conjugation|
|Advantages||Time-efficient requires less energy.||A genetic variation that makes the organism unique.|
|Disadvantages||No genetic variation||Requires two organisms, requires more energy.|
|Example||Bacterial fission, budding of yeast, budding of hydra||Reproduction in human|
What is Asexual Reproduction?
Asexual reproduction is the reproduction without sex. In this reproduction, a single organism or cell makes a copy of itself. The genes of the parent organism and offspring remain the same except for rare mutations. They are clones. The major process of this reproduction is mitosis. Asexual reproduction is common among single-cell organisms, such as in amoeba. Many plants also reproduce by this type of reproduction.
There are several asexual reproductions; budding, fission, fragmentation and spore formation, etc. In binary fission, a cell splits and becomes two cells. Some organisms, such as bacteria reproduce by binary fission. Bacteria splits into two, so one bacterium becomes two bacteria. The new daughter cells will be identical to the parent bacterium. Binary fission is common in prokaryotes. Genetic makeup remains the same in the case of binary fission, but in some cases, a mutation occurs. But mutation shows slight differences. Daughter cells then divide to produce more offspring and so on.
Budding is similar to binary fission. Budding occurs in some plants and animals which can not simply split into two daughter cells. In this type of asexual reproduction, a small part of the plant or animal breaks off and starts to grow until it becomes similar in size like a parent. This process may happen multiple times.
What is Sexual Reproduction?
Some animals and plants reproduce by way of sexual reproduction. Some protists and fungi also reproduce by this type of reproduction. Sexual reproduction uses two different sexes; male and female. Offspring is produced by the combination of a cell from the male and a cell from the female. But this process consists of different steps.
The cells of the organisms undergoing sexual reproduction have two sets of chromosomes, which are called diploid. When gametes are produced, they have only one set of chromosomes, which are called haploid. Gametes undergo a process of cell division, meiosis. During this cell division, crossing over occurs, which makes it possible to get recombination. This has different consequences. For example, all the children of the parents are not identical except in rare cases.
The second step is called fertilization, in which the two cells merge into one. This restores the diploid state. In fertilization, the female’s ovum joins together with a male’s sperm and form a zygote. The zygote is the fertilized egg. Fertilization is also called conception. A zygote grows into the baby animal. The zygote then multiplies and develops into an embryo. The time between the zygote formation and the baby’s birth is called pregnancy.
Some animals keep the zygote inside their bodies until it is a full-grown baby. While some animals do not keep the zygote in their bodies but lay eggs. The zygote nurtures inside the egg until it is ready and the baby animal hatches. The fertilized now starts to divide and produce the embryo. It is called an embryo from 3 to 8 weeks. Then after eight weeks, it is called a fetus. If it remains to grow normally, it can eventually become a baby.
- Asexual reproduction is uniparental, whereas sexual reproduction is biparental.
- Sex organs are not formed in asexual reproduction, whereas sex organs are formed in sexual reproduction.
- In asexual reproduction, all cells divide by mitosis, whereas, in sexual reproduction, all cells divide by meiosis.
- In asexual reproduction, the zygote is not formed, whereas, in sexual reproduction, zygote formation occurs by the fusion of gametes.
- In asexual reproduction, progeny and the parent will have the same genetic makeup, whereas, in sexual reproduction, progeny and parent will be different in genetic makeup.
- In asexual reproduction, a large number of progenies are produced, whereas, in sexual reproduction, a limited number of progenies are produced.
- Asexual reproduction has no evolutionary significance, whereas sexual reproduction has evolutionary significance in the population.
- Asexual reproduction requires less time, whereas sexual reproduction requires more time.
In conclusion, asexual reproduction is uniparental and produces multiple offspring, whereas sexual reproduction is biparental produces one or more offspring. These two types of reproductions also differ from each other in many aspects.