What is a diploid
Under Diploidy (from Greek diploe = Duplicity) In genetics, the presence of two complete sets of chromosomes is understood as a so-called double set of chromosomes. Each chromosome is thus present in double number, whereby in the gonosomes of male individuals no distinction is made between the normally different X and Y chromosomes. Since this is the common condition in humans as well as in many animals and plants, it is also known as euploidy. But there are also exceptions, e.g. B. due to generation cycles or different genders.
Plants with a phase change
Most plants go through a generation change, nuclear phase change, in which a haploid (simple set of chromosomes) and a diploid phase alternate:
- In mosses (Bryophytina), the haploid generation (gametophyte) is what you see as a green moss plant (leafed or as a thallus). Fertilization creates a smaller diploid sporophyte that grows out of the moss plant, forms a spore capsule in which meiosis takes place, so that haploid spores are formed. The spores are scattered in the wind or by rain, germinate and a new haploid gametophyte grows.
- In ferns (Pteridophytina), horsetail (Equisetopsida, belongs to the Pteridophytina) and club moss plants (Lycopodiopsida, also belongs to the Pteridophytina), the large visible plant is the diploid sporophyte, which forms haploid spores after meiosis. A small gametophyte, the prothallium, arises from them. The sporophyte grows again from its fertilized egg cells. But there are also polyploid ferns (sporophytes).
- In seed plants (Spermatophytina), the diploid sporophyte is what we see as trees, shrubs or herbaceous plants. The gametophytes are greatly reduced: the pollen grains (together with the egg cell) represent the haploid generation. In the naked samers (gymnosperms), the pollen reaches the ovule directly, which is not surrounded by an ovary, i.e. has no stigma or stylus. Fertilization then takes place in the ovule. In angiosperms (= Magnoliopsida), the pollen grows after pollination through the stylus to the egg cell, where fertilization takes place.
Some animals, for example insects (Insecta), are sexed by whether they are haploid or diploid (haplodiploidy). The female bees or ants are diploid (workers and queens), while the males (drones) are haploid.
Higher set of chromosomes
Polyploidy (three to eight chromosome sets) leads to e.g. B. in cereals to particularly high-yielding varieties, but in most organisms to malformations. Only a few organisms are polyploid, including animal life forms.
- Seyffert, Genetics textbook, 2nd edition, Spektrum, Akad. Verl., Heidelberg 2003.
- What are the Greek people in Melbourne
- Can you help me get better
- Which software model is used in Google
- Can beat Saitama better than Zeno
- What deserves your attention
- Prefer muffins or bagels
- How can I make money with VPS
- What are some applications of thermodynamics
- What is a train PNR status
- Is tobacco traded on the MCX
- How easy is it to port Java
- Uses Leonardo DiCaprio Quora
- Can dermatologists help with hair loss
- Which books should Java self-learners read?
- How do I apply for an apprenticeship
- Which came first, life forms or DNA
- What is impossible for technology
- What I don't do medically after +2
- What are some fun playground games
- Danger cheap smartphones users
- How do backlinks affect my website rank?
- What did Shivaji really look like?
- Works Mint Com in the UK
- How many cats are on Twitter
- Why should an import business be illegal?
- How can I access a Comcast modem
- Why are sunglasses polarized
- How do deaf blind learn grammar
- What is metabolism in biology
- Why are reactive metals extracted by electrolysis
- What is public property damage
- Elementary OS is Debian-based Linux
- What do Americans think of instant noodles?
- How important is the speed in a mixer