- published: 01 Oct 2012
- views: 327206
In biology, a life cycle is a series of changes in form that an organism undergoes, returning to the starting state. "The concept is closely related to those of the life history, development and ontogeny, but differs from them in stressing renewal." Transitions of form may involve growth, asexual reproduction, and/or sexual reproduction.
In some organisms, different "generations" of the species succeed each other during the life cycle. For plants and many algae, there are two multicellular stages, and the life cycle is referred to as alternation of generations. The term life history is often used, particularly for organisms such as the red algae which have three multicellular stages (or more), rather than two.
Life cycles that include sexual reproduction involve alternating haploid (n) and diploid (2n) stages, i.e., a change of ploidy is involved. To return from a diploid stage to a haploid stage, meiosis must occur. In regard to changes of ploidy, there are 3 types of cycles:
Life cycle may refer to:
Life is a characteristic distinguishing physical entities having biological processes (such as signaling and self-sustaining processes) from those that do not, either because such functions have ceased (death), or because they lack such functions and are classified as inanimate. Various forms of life exist such as plants, animals, fungi, protists, archaea, and bacteria. The criteria can at times be ambiguous and may or may not define viruses, viroids or potential artificial life as living. Biology is the primary science concerned with the study of life, although many other sciences are involved.
Throughout history there have been many theories about life including materialism, hylomorphism and vitalism. Even today it is a challenge for scientists and philosophers to define life. The smallest contiguous unit of life is called an organism. Organisms are composed of one or more cells, undergo metabolism, maintain homeostasis, can grow, respond to stimuli, reproduce (either sexually or asexually) and, through evolution, adapt to their environment in successive generations. A diverse array of living organisms can be found in the biosphere of Earth, and the properties common to these organisms are a carbon- and water-based cellular form with complex organization and heritable genetic information.
The Sex Lives of Nonvascular Plants: Alternation of Generations - Crash Course Biology #36
The life cycle of whitefly
The Malaria life cycle explained. Should interest a lot of people.
Fern Life Cycle
The life cycle of aphids
Plants & Fungi 2- Plant lifecycle
Malaria Lifecycle Animation
Biological Life Cycle of Fleas
Cat Flea Biology
Propomacrus cypriacus biological life cycle - Video - Cyprus
Hank introduces us to nonvascular plants - liverworts, hornworts & mosses - which have bizarre features, kooky habits, and strange sex lives. Nonvascular plants inherited their reproductive cycle from algae, but have perfected it to the point where it is now used by all plants in one way or another, and has even left traces in our own reproductive systems. Crash Course Biology is now available on DVD! http://dft.ba/-8bCC Like CrashCourse? http://www.facebook.com/YouTubeCrashCourse Follow CrashCourse! http://www.twitter.com/TheCrashCourse Table of Contents 1) Key Traits of Nonvascular Plants 01:42 2) 3 Phyla of Bryophytes 02:52 3) Alternation of Generations 04:33 a) Gametophyte Generation 05:04 b) Sporophyte Generation 05:25 c) In Vascular Plants 07:48 References for this episode can be...
Whiteflies form a major threat for many vegetable and ornamental crops. The adults can be recognized by their waxy wings. Whiteflies have well developed needle-like mouthparts. They extract sap from the underside of plant leaves and secrete honeydew. This honeydew, in turn, is a nutrient source for sooty moulds. The female lays her eggs on the underside of young leaves. If she has not yet mated, all of the eggs will develop into males. The eggs have a white/yellowish colour, are oblong shaped and are often deposited in circles. After one or two days, they become darker in colour. The nymphs that emerge from the eggs are known as ‘crawlers’. Crawlers move around for several hours before settling on the leaf. They moult into their second stage and become immobile. The nymph starts to fe...
Aphids inflict serious damage to a variety of crops. They are notorious virus vectors and have an enormous reproductive capacity. There are lots of different coloured species and they occur in all kinds of crops. The nymphs and adults extract food materials from the plant and disturb the balance of the plant’s growth hormones. It can result in deformed leaves or even the death of young plants. Aphids secrete honeydew which is a nutrient source for sooty moulds. Their saliva can also induce strong allergic reactions such as malformations of the growing tips. The aphid in this video is the most important vector of viruses and is thus feared by many growers. When reproduction is asexual, the young aphids are born as developed nymphs. They immediately start to feed on plant sap and grow rap...
Part 2 in an 8 part lecture on PLANTS & FUNGI in a flipped General Biology course taught by Wendy Riggs. CC-BY. Watch the whole lecture (all 8 videos) by going to the PLAYLIST: https://www.youtube.com/playlist?list=PL5GRRRmaGVqVJm2KEZmF776Wx2F3KltQP
In her pursuit to be a Veterinary Doctor, Zhansu studies one of the many sickness in pets, the life cycle of fleas on cats. Vidoe taken by Irene
Urban entomology expert Philip Koehler explains how fleas live and breed around — or on — your cat. Includes feeding, mating and life cycle of the cat flea (Ctenocephalides felis). Produced by UF/IFAS Entomology and Nematology Department Visit us at http://entomology.ifas.ufl.edu
Propomacrus cypriacus( Alexis & Makris, 2002 ) Endemic species of Cyprus A beetle in the family Euchiridae (Scarabaeoidea) Ιt was included in Annex II of the 92/43/EEC Directive after a proposal of Cyprus Republic as a rare, endemic and charismatic species. Life Cycle Ova: August -September Larva development: One or two years Pupa: June - July Adult: July – early October Host Plants: Larva sapro-xylophagous on rotting wood in hollows of broad leaved trees. Quercus infectoria subsp. veneris Ceratonia siliqua Prunus dulcis
This is a 50 frame animation created in Adobe Animate as part of an online course. The goal was to make a line walking across the stage and transform at the end.
This is a special video series about the Madagascan Hissing Cockroach lifecycle from birth.
This video dates from September 3, 2016 to September 28, 2016. This whole process was so fun to experience and watch with my 7 year old son. It all took place right on our balcony. We didn't buy the caterpillars online and receive them in a box. This is just nature at it's purest! Enjoy!
made by Videolicious
We have been breeding Monarch Butterflies for the past 3 years and we want to share this beautiful life cycle with you. Over the next 10 weeks we will share with you tips to prevent wasps killing your caterpillars and just how amazing this life cycle is, from egg to caterpillar to beautiful butterfly. Make sure you subscribe so you don't miss out on any of our fun, educational, craft and kids food videos. Thanks for watching.
Students at Levy get a hands-on learning experience by raising Black Swallowtail Butterflies from eggs.
Read your free e-book: http://copydl.space/mebk/50/en/B0044KLNVW/book The Long Shadow of Sexual Abuse: Developmental Effects across the Life Cycle has one simple purpose_to describe the profound interferences with normal developmental processes that occur in every subsequent developmental phase throughout life as the result of chronic child sexual abuse. Through the presentation of detailed case histories of individuals ranging in age from five to the early sixties, Colarusso convincingly demonstrates that the effects are life long. Sections on normal development for childhood, adolescence, young, and middle adulthood are followed by case histories, arranged chronologically according to the age of the victims at the time they were evaluated. Then the effects of the sexual abuse are traced ...
from sperm until give birth a baby
I use this PowerPoint in my biology class at Beverly Hills High School. Topics: - Alternation of generations - Bryophytes - Mosses - Sporophyte - Gametophyte - Moss life cycle
GCSE level Cosmology covering: Star life cycle, Life Cycle, Protostar, Main sequence, red giant, neutron star, black hole, supernova, fusion
This video has been developed by Shweta Sardana Madam of Sardana Tutorials. This video lesson covers following all the points plasmodium vivax,Malaria Parasite,Malaria and Plasmodium,Life cycle of Plasmodium,plasmodium falciparum,plasmodium falciparum life cycle, Plasmodium Malari,Mosquito paracite,mosquito parasito,digenic parasite, Kingdom Protesta, prostitian protozoa, sporozoa This video is also useful for 11th CBSE, 12th CBSE, AIPMT Biology, NEET Biology. If you need to watch more videos for 11th CBSE biology, 12th CBSE Biology, AIPMT biology lectures, NEET biology lectures then subscribe our channel. http://www.youtube.com/user/sardanatutorials
A lecture given by Prof. Steve Martin at the 2014 National Honey Show entitled "Basic Life Cycles of Wasps and Hornets". The National Honey Show gratefully acknowledge the sponsorship of the Garfield Weston Foundation and The Central Association of Beekeepers.
New life dawns - the inception of another link in a
profound process
Alteration and progress, nothing remains the same
Like a from from the egg to the tadpole to the final
stage
Everything develops, learns, there's always reason almost
rhyme!
Like a spirit staircase that someday, somehow will end
Even the world's life cycle ends when progression's
altered (synthetically)
I stalked the blissful fields of springtime, I comprehend
and I remind
And I will taste the bleary bleakness of autumn time, in
due time I will find!
Genesis, search, consumation - no living thing is
extempted
Confined knowledge cannot understand - harmonious
symbiosis!
Life cycles - almost everywhere!
Life cycles - permanent progress!