Shopping on line can be easy, simple and save you lots of money. It can also take a lot of your time, frustrate you, and result in unwanted purchases. Now the same can be said for regular high street shopping, but with the vast opportunity presented by the Internet it will pay you to spend a few minutes reading this and understanding how to better optimize your Ovum shopping experience:
1. Compare - without doubt the biggest advantage that the Ovum offers shoppers today is the ability to compare thousands of Ovum at a time. This is a great thing, but not necessarily all the time! Too much can be daunting at times so take advantage of the great comparison sites and where possible let them do the hard work for you.
2. Research - if it has been said it will be on the internet. Ignorance is no longer a justifiable reason for buying the wrong thing. Take the time to research in detail everything that you could possible want to know about
3. Testimonials - don't know anybody that has bought a Ovum? Wrong! If the Ovum is good the internet will let you know. Use the Internet as a friend and get testimonials before you buy.
4. Questions - Got a question about Ovum then search the Forums, FAQ's, Blogs etc. Don't be afraid to ask .....
5. Reputation - Never heard of the company selling Ovum? Don't worry, no reason why you should know every company in the world, but you know someone that does! Use the internet to find out what people are saying about Ovum and build up a picture of their reputation for sales, returns, customer service, delivery etc.
6. Returns - still worried that even after all of the above your Ovum wont be what you want? Check out the returns policy. There is so much competition now that someone, somewhere is bound to offer the terms that you are comfortable with.
7. Feedback - happy with your Ovum then let people know, after all you are depending on others people input in your buying decision, so why not give a little back.
8. Security - check for the yellow padlock on the Ovum site before you buy, and the s after http:/ /i.e. https:// = a secure site
9. Contact - got a question about Ovum, or want to leave a comment then check out the sites contact page. Reputable companies have them and respond.
10. Payment - ready to pay for your Ovum, then use your credit card or PayPal! Be aware of companies that don't accept them, there may be genuine reasons but given the huge amount of choice you have when buying online there is no reason at all not to buy via credit card or PayPal.
An
ovum (plural
ova) is a
haploid female reproductive cell or
gamete. The word is derived from
Latin language, meaning egg (biology) or
egg (biology). Both
animals and embryophytes have ova. The term
ovule is used for the young ovum of an animal, as well as the plant structure that carries the female
gametophyte and egg cell and develops into a seed after fertilization. In some plants, such as algae, it is also called
oosphere.
Material contribution to offspring
The egg is the sole provider of such
endosymbiont organelles, including mitochondria within the cytoplasm. These cannot be produced with nuclear DNA alone and must be manufactured from DNA within existing organelles of their type (such as
mitochondrial DNA) — this is important in
Human mitochondrial genetics and can be used to trace maternal and paternal ancestry, especially as plants contain chloroplasts as well. Sperm are often too small to contribute anything physical except DNA and its own mitochondria gets destroyed by the egg.
Ova production
In higher animals, ova are produced by female gonads (sexual glands) called ovary and all of them are present at birth in
mammals, and mature via
oogenesis.
Human and mammal ova
In the viviparous animals (which include
humans and all other
Eutherias), the ovum is fertilized inside the female body, and the embryo then develops inside the
uterus, receiving nutrition directly from the mother. The ovum is the largest
biological cell in the human body, typically visible to the naked eye without the aid of a
microscope or other magnification device. The human ovum measures on average, 145 micrometre in diameter.
Protist and plant ova
In protists, Fungus and many plants, such as bryophytes,
ferns, and gymnosperms, ova are produced inside
Archegonium. Since the archegonium is a
haploid structure, egg cells are produced via mitosis. The typical bryophyte archegonium consists of a long neck with a wider base containing the egg cell. Upon maturation, the neck opens to allow sperm cells to swim into the archegonium and fertilize the egg. The resulting zygote then gives rise to an embryo, which will grow out of the archegonium as a sporeling (young sporophyte).
In the
flowering plants, the female gametophyte, which usually gives rise to the archegonium, has been reduced to just eight cells referred to as the
embryo sac inside the ovule. The gametophyte cell closest to the
micropyle opening of the embryo sac develops into the egg cell. Upon pollination, a pollen tube delivers
sperm into the embryo sac and one sperm nucleus fuses with the egg nucleus. The resulting zygote develops into an embryo inside the ovule. The ovule in turn develops into a
seed and in many cases the
Ovary (plants) develops into a fruit to facilitate the Biological dispersal of the seeds. Upon germination, the embryo grows into a
seedling.
Ova development in oviparous animals
In the oviparous animals (all birds, most
fishes,
amphibians and reptiles) the ova develop protective layers and pass through the
oviduct to the outside of the body. They are fertilization by male sperm either inside the female body (as in birds), or outside (as in many fishes). After fertilization, an
embryo develops, nourished by nutrients contained in the egg. It then hatches from the egg, outside the mother's body. See
egg (biology) for a discussion of eggs of oviparous animals.
The egg cell's cytoplasm and mitochondria (and chloroplasts in plants) are the sole means of the egg being able to reproduce by
mitosis and eventually form a blastocyst after fertilization.
Ovoviviparity
There is an intermediate form, the Ovoviviparity animals: the embryo develops within and is nourished by an egg as in the oviparous case, but then it hatches inside the mother's body shortly before birth, or just after the egg leaves the mother's body. Some fish, reptiles and many invertebrates use this technique.
See also
External links
- The Ovarian Kaleidoscope Database description of 1800 genes involved in ovarian functions
An
ovum (plural
ova) is a haploid female reproductive cell or
gamete. The word is derived from Latin language, meaning
egg (biology) or egg (biology). Both
animals and
embryophytes have ova. The term
ovule is used for the young ovum of an animal, as well as the plant structure that carries the female
gametophyte and egg cell and develops into a seed after fertilization. In some
plants, such as algae, it is also called
oosphere.
Material contribution to offspring
The egg is the sole provider of such
endosymbiont organelles, including mitochondria within the cytoplasm. These cannot be produced with nuclear DNA alone and must be manufactured from DNA within existing organelles of their type (such as mitochondrial DNA) — this is important in Human mitochondrial genetics and can be used to trace maternal and paternal
ancestry, especially as plants contain chloroplasts as well. Sperm are often too small to contribute anything physical except DNA and its own mitochondria gets destroyed by the egg.
Ova production
In higher animals, ova are produced by female
gonads (sexual glands) called ovary and all of them are present at birth in
mammals, and mature via oogenesis.
Human and mammal ova
In the
viviparous animals (which include
humans and all other
Eutherias), the ovum is fertilized inside the female body, and the
embryo then develops inside the uterus, receiving nutrition directly from the mother. The ovum is the largest
biological cell in the human body, typically visible to the naked eye without the aid of a
microscope or other magnification device. The human ovum measures on average, 145 micrometre in diameter.
Protist and plant ova
In
protists, Fungus and many plants, such as bryophytes, ferns, and gymnosperms, ova are produced inside
Archegonium. Since the archegonium is a haploid structure, egg cells are produced via
mitosis. The typical bryophyte archegonium consists of a long neck with a wider base containing the egg cell. Upon maturation, the neck opens to allow sperm cells to swim into the archegonium and fertilize the egg. The resulting zygote then gives rise to an embryo, which will grow out of the archegonium as a sporeling (young sporophyte).
In the
flowering plants, the female gametophyte, which usually gives rise to the archegonium, has been reduced to just eight cells referred to as the
embryo sac inside the
ovule. The gametophyte cell closest to the
micropyle opening of the embryo sac develops into the egg cell. Upon
pollination, a pollen tube delivers
sperm into the embryo sac and one sperm nucleus fuses with the egg nucleus. The resulting zygote develops into an embryo inside the ovule. The ovule in turn develops into a
seed and in many cases the
Ovary (plants) develops into a
fruit to facilitate the Biological dispersal of the seeds. Upon germination, the embryo grows into a
seedling.
Ova development in oviparous animals
In the oviparous animals (all
birds, most
fishes, amphibians and reptiles) the ova develop protective layers and pass through the oviduct to the outside of the body. They are
fertilization by male
sperm either inside the female body (as in birds), or outside (as in many fishes). After fertilization, an embryo develops, nourished by nutrients contained in the egg. It then hatches from the egg, outside the mother's body. See
egg (biology) for a discussion of eggs of oviparous animals.
The egg cell's cytoplasm and mitochondria (and chloroplasts in plants) are the sole means of the egg being able to reproduce by
mitosis and eventually form a
blastocyst after fertilization.
Ovoviviparity
There is an intermediate form, the Ovoviviparity animals: the embryo develops within and is nourished by an egg as in the oviparous case, but then it hatches inside the mother's body shortly before birth, or just after the egg leaves the mother's body. Some fish, reptiles and many invertebrates use this technique.
See also
External links
- The Ovarian Kaleidoscope Database description of 1800 genes involved in ovarian functions
Telecoms and Software Consulting (OVUM)
Advising on the commercial impact of technology and market changes in telecoms, software and IT services.
Who we are
At Ovum we fully understand convergence across telecoms, IT services and software. We invest heavily in researching what is happening in a market that is dynamic and full of risk ...
Ovum Research: Telecom Report, ICT advice
Advising on the commercial impact of technology and market changes in Telecoms, Software and IT services. Software and Telecom market forcasts, research and Vendor Analysis.
Telecoms and Software News
This article is an extract taken from Ovum's Straight Talk service. This daily email bulletin provides our expert's views and opinions on important news and events in global IT and ...
Definition: ovum from Online Medical Dictionary
The Online Medical Dictionary is a searchable dictionary of definitions from medicine, science and technology.
Signin
Please click the above Guest User link and enter your details if you would like to join Ovum's mailing list and be sent occasional updates about new web/podcasts, new research ...
Ovum - Wikipedia, the free encyclopedia
An ovum (plural ova) is a haploid female reproductive cell or gamete. The word is derived from Latin, meaning egg or egg cell. Both animals and embryophytes have ova.
Ovum ::
Minimal and progressive house label established by Josh Wink in 1994. Artists include Pete Moss and DJ Dozia. Website features artist information and audio samples.
Ovum Content at ZDNet UK
News Articles, Whitepapers, Downloads, Opinion and Resources relating to Ovum ... Ovum Summit IT Service Management Vendor Report Card. White Papers See how the players stack up in ...
AskOxford: ovum
ovum • noun (pl. ova) a mature female reproductive cell, which can divide to give rise to an embryo usually only after fertilization by a male cell.
