banner



Home  ›  In Plants And Animals, The Zygote Develops Into An Embryo By What Process?

In Plants And Animals, The Zygote Develops Into An Embryo By What Process?

Written By Friday, June 17, 2022 Add Comment Edit

Reproduction procedure that creates a new organism past combining the genetic material of two organisms

In the start stage of sexual reproduction, "meiosis", the number of chromosomes is reduced from a diploid number (2n) to a haploid number (n). During "fertilisation", haploid gametes come together to form a diploid zygote, and the original number of chromosomes is restored.

Sexual reproduction is a type of reproduction that involves a circuitous life cycle in which a gamete (such as a sperm or egg cell) with a single gear up of chromosomes (haploid) combines with another to produce a zygote that develops into an organism composed of cells with 2 sets of chromosomes (diploid).[1] Sexual reproduction is the nearly common life cycle in multicellular eukaryotes, such equally animals, fungi and plants. Sexual reproduction does not occur in prokaryotes (organisms without cell nuclei), but they take processes with like effects such equally bacterial conjugation, transformation and transduction, which may have been precursors to sexual reproduction in early eukaryotes.

In the production of sexual practice cells in eukaryotes, diploid mother cells divide to produce haploid cells known as gametes in a process called meiosis that involves genetic recombination. The homologous chromosomes pair upwardly so that their Dna sequences are aligned with each other, and this is followed by exchange of genetic information betwixt them. Two rounds of cell sectionalization and so produce four haploid gametes, each with half the number of chromosomes from each parent cell, only with the genetic data in the parental chromosomes recombined. Two haploid gametes combine into 1 diploid cell known as a zygote in a process chosen fertilisation. The zygote incorporates genetic fabric from both gametes. Multiple jail cell divisions, without alter of the number of chromosomes, then form a multicellular diploid phase or generation.

In human reproduction, each cell contains 46 chromosomes in 23 pairs. Meiosis in the parents' gonads produces gametes that each incorporate only 23 chromosomes that are genetic recombinants of the Dna sequences contained in the parental chromosomes. When the nuclei of the gametes come together to form a fertilized egg or zygote, each cell of the resulting child will accept 23 chromosomes from each parent, or 46 in total.[2] [3]

In plants only, the diploid phase, known as the sporophyte, produces spores by meiosis that germinate and and so divide past mitosis to form a haploid multicellular stage, the gametophyte, that produces gametes direct past mitosis. This type of life cycle, involving alternation between two multicellular phases, the sexual haploid gametophyte and asexual diploid sporophyte, is known as alternation of generations.

The evolution of sexual reproduction is considered paradoxical,[3] because asexual reproduction should exist able to outperform it as every young organism created can bear its own young. This implies that an asexual population has an intrinsic chapters to abound more rapidly with each generation.[4] This fifty% cost is a fettle disadvantage of sexual reproduction.[5] The ii-fold price of sex includes this cost and the fact that any organism tin only pass on 50% of its ain genes to its offspring. One definite advantage of sexual reproduction is that it impedes the aggregating of genetic mutations.[vi]

Sexual selection is a style of natural option in which some individuals out-reproduce others of a population because they are ameliorate at securing mates for sexual reproduction.[seven] [viii] It has been described equally "a powerful evolutionary force that does not exist in asexual populations."[nine]

Evolution [edit]

The first fossilized evidence of sexual reproduction in eukaryotes is from the Stenian menstruation, almost one.05  billion years ago.[ten] [xi]

Biologists studying evolution suggest several explanations for the evolution of sexual reproduction and its maintenance. These reasons include reducing the likelihood of the accumulation of deleterious mutations, increasing charge per unit of adaptation to changing environments,[12] dealing with competition, Dna repair and masking deleterious mutations.[13] [xiv] [15] All of these ideas about why sexual reproduction has been maintained are generally supported, but ultimately the size of the population determines if sexual reproduction is entirely beneficial. Larger populations appear to respond more chop-chop to some of the benefits obtained through sexual reproduction than do smaller population sizes.[16]

Maintenance of sexual reproduction has been explained past theories that work at several levels of choice, though some of these models remain controversial.[ citation needed ] However, newer models presented in contempo years suggest a basic reward for sexual reproduction in slowly reproducing complex organisms.

Sexual reproduction allows these species to showroom characteristics that depend on the specific environment that they inhabit, and the particular survival strategies that they employ.[17]

Sexual pick [edit]

In lodge to reproduce sexually, both males and females need to observe a mate. Generally in animals mate choice is fabricated past females while males compete to be chosen. This tin can atomic number 82 organisms to extreme efforts in order to reproduce, such every bit combat and brandish, or produce extreme features caused by a positive feedback known every bit a Fisherian delinquent. Thus sexual reproduction, as a course of natural selection, has an outcome on evolution. Sexual dimorphism is where the bones phenotypic traits vary between males and females of the same species. Dimorphism is plant in both sexual practice organs and in secondary sex characteristics, body size, physical strength and morphology, biological ornamentation, behavior and other bodily traits. However, sexual selection is only implied over an extended period of time leading to sexual dimorphism.[xviii]

Animals [edit]

Insects [edit]

Insect species brand up more than two-thirds of all extant animal species. Most insect species reproduce sexually, though some species are facultatively parthenogenetic. Many insects species have sexual dimorphism, while in others the sexes look nearly identical. Typically they have two sexes with males producing spermatozoa and females ova. The ova develop into eggs that have a covering chosen the chorion, which forms earlier internal fertilization. Insects take very diverse mating and reproductive strategies near often resulting in the male person depositing spermatophore within the female person, which she stores until she is ready for egg fertilization. After fertilization, and the formation of a zygote, and varying degrees of evolution, in many species the eggs are deposited outside the female; while in others, they develop farther within the female person and are built-in live.

Mammals [edit]

There are three extant kinds of mammals: monotremes, placentals and marsupials, all with internal fertilization. In placental mammals, offspring are born as juveniles: consummate animals with the sex activity organs present although non reproductively functional. Later on several months or years, depending on the species, the sex activity organs develop further to maturity and the animal becomes sexually mature. Most female mammals are only fertile during sure periods during their estrous bicycle, at which point they are ready to mate. Private male and female mammals meet and comport out copulation.[ citation needed ] For most mammals, males and females exchange sexual partners throughout their developed lives.[19] [20] [21]

Fish [edit]

The vast majority of fish species lay eggs that are then fertilized by the male.[22] Some species lay their eggs on a substrate like a rock or on plants, while others besprinkle their eggs and the eggs are fertilized as they migrate or sink in the h2o column.

Some fish species use internal fertilization and then disperse the developing eggs or give nascency to live offspring. Fish that accept alive-begetting offspring include the guppy and mollies or Poecilia. Fishes that requite birth to live young can be ovoviviparous, where the eggs are fertilized within the female person and the eggs simply hatch within the female person body, or in seahorses, the male carries the developing young within a pouch, and gives birth to live young.[23] Fishes tin also be viviparous, where the female supplies nourishment to the internally growing offspring. Some fish are hermaphrodites, where a single fish is both male person and female person and tin produce eggs and sperm. In hermaphroditic fish, some are male and female at the same fourth dimension while in other fish they are serially hermaphroditic; starting as i sexual activity and changing to the other. In at least one hermaphroditic species, self-fertilization occurs when the eggs and sperm are released together. Internal self-fertilization may occur in some other species.[24] One fish species does not reproduce by sexual reproduction only uses sex to produce offspring; Poecilia formosa is a unisex species that uses a form of parthenogenesis called gynogenesis, where unfertilized eggs develop into embryos that produce female offspring. Poecilia formosa mate with males of other fish species that apply internal fertilization, the sperm does not fertilize the eggs merely stimulates the growth of the eggs which develops into embryos.[25]

Plants [edit]

Animals have life cycles with a single diploid multicellular phase that produces haploid gametes direct by meiosis. Male gametes are called sperm, and female gametes are chosen eggs or ova. In animals, fertilization of the ovum past a sperm results in the formation of a diploid zygote that develops past repeated mitotic divisions into a diploid adult. Plants take two multicellular life-cycle phases, resulting in an alternation of generations. Plant zygotes germinate and separate repeatedly by mitosis to produce a diploid multicellular organism known as the sporophyte. The mature sporophyte produces haploid spores past meiosis that germinate and divide by mitosis to form a multicellular gametophyte phase that produces gametes at maturity. The gametophytes of unlike groups of plants vary in size. Mosses and other pteridophytic plants may accept gametophytes consisting of several million cells, while angiosperms have equally few as iii cells in each pollen grain.

Flowering plants [edit]

Flowers contain the sexual organs of flowering plants.

Flowering plants are the ascendant institute grade on state[26] : 168, 173 and they reproduce either sexually or asexually. Ofttimes their almost distinguishing feature is their reproductive organs, commonly called flowers. The anther produces pollen grains which comprise the male person gametophytes that produce sperm nuclei. For pollination to occur, pollen grains must adhere to the stigma of the female person reproductive structure (carpel), where the female person gametophytes are located within ovules enclose within the ovary. After the pollen tube grows through the carpel's manner, the sex activity prison cell nuclei from the pollen grain drift into the ovule to fertilize the egg cell and endosperm nuclei within the female gametophyte in a procedure termed double fertilization. The resulting zygote develops into an embryo, while the triploid endosperm (one sperm prison cell plus two female cells) and female person tissues of the ovule give ascent to the surrounding tissues in the developing seed. The ovary, which produced the female gametophyte(due south), and then grows into a fruit, which surrounds the seed(s). Plants may either self-pollinate or cantankerous-pollinate.

In 2013, flowers dating from the Cretaceous (100 one thousand thousand years earlier present) were plant encased in bister, the oldest evidence of sexual reproduction in a flowering institute. Microscopic images showed tubes growing out of pollen and penetrating the flower'south stigma. The pollen was sticky, suggesting information technology was carried by insects.[27]

Nonflowering plants similar ferns, moss and liverworts use other means of sexual reproduction.

Ferns [edit]

Ferns produce big diploid sporophytes with rhizomes, roots and leaves. Fertile leaves produce sporangia that comprise haploid spores. The spores are released and germinate to produce small, thin gametophytes that are typically heart shaped and green in color. The gametophyte prothalli, produce motile sperm in the antheridia and egg cells in archegonia on the same or different plants. Later on rains or when dew deposits a pic of water, the motile sperm are splashed away from the antheridia, which are normally produced on the acme side of the thallus, and swim in the film of water to the archegonia where they fertilize the egg. To promote out crossing or cross fertilization the sperm are released before the eggs are receptive of the sperm, making it more likely that the sperm will fertilize the eggs of different thallus. After fertilization, a zygote is formed which grows into a new sporophytic plant. The condition of having separate sporophyte and gametophyte plants is called alternation of generations. Other plants with similar life cycles include Psilotum, Lycopodium and Equisetum.

Bryophytes [edit]

The bryophytes, which include liverworts, hornworts and mosses, reproduce both sexually and vegetatively. They are pocket-size plants constitute growing in moist locations and like ferns, have motile sperm with flagella and need water to facilitate sexual reproduction. These plants start equally a haploid spore that grows into the dominant gametophyte form, which is a multicellular haploid body with leaf-similar structures that photosynthesize. Haploid gametes are produced in antheridia (male) and archegonia (female) by mitosis. The sperm released from the antheridia answer to chemicals released by ripe archegonia and swim to them in a picture of h2o and fertilize the egg cells thus producing a zygote. The zygote divides by mitotic partitioning and grows into a multicellular, diploid sporophyte. The sporophyte produces spore capsules (sporangia), which are connected by stalks (setae) to the archegonia. The spore capsules produce spores by meiosis and when ripe the capsules outburst open to release the spores. Bryophytes evidence considerable variation in their reproductive structures and the above is a basic outline. Also in some species each plant is one sex (dioicous) while other species produce both sexes on the aforementioned plant (monoicous).[28]

Fungi [edit]

Puffballs emitting spores

Fungi are classified by the methods of sexual reproduction they employ. The issue of sexual reproduction about often is the production of resting spores that are used to survive inclement times and to spread. At that place are typically three phases in the sexual reproduction of fungi: plasmogamy, karyogamy and meiosis. The cytoplasm of two parent cells fuse during plasmogamy and the nuclei fuse during karyogamy. New haploid gametes are formed during meiosis and develop into spores. The adaptive basis for the maintenance of sexual reproduction in the Ascomycota and Basidiomycota (dikaryon) fungi was reviewed by Wallen and Perlin.[29] They concluded that the almost plausible reason for maintaining this capability is the benefit of repairing Deoxyribonucleic acid harm, caused by a variety of stresses, through recombination that occurs during meiosis.[29]

Bacteria and archaea [edit]

Three singled-out processes in prokaryotes are regarded as similar to eukaryotic sex: bacterial transformation, which involves the incorporation of foreign Dna into the bacterial chromosome; bacterial conjugation, which is a transfer of plasmid Dna between bacteria, but the plasmids are rarely incorporated into the bacterial chromosome; and gene transfer and genetic exchange in archaea.

Bacterial transformation involves the recombination of genetic fabric and its function is mainly associated with Deoxyribonucleic acid repair. Bacterial transformation is a complex procedure encoded by numerous bacterial genes, and is a bacterial adaptation for Deoxyribonucleic acid transfer.[xiii] [14] This process occurs naturally in at least 40 bacterial species.[xxx] For a bacterium to demark, take up, and recombine exogenous DNA into its chromosome, it must enter a special physiological state referred to equally competence (run across Natural competence). Sexual reproduction in early on single-celled eukaryotes may have evolved from bacterial transformation,[fifteen] or from a similar process in archaea (see below).

On the other hand, bacterial conjugation is a type of direct transfer of Deoxyribonucleic acid between two leaner mediated by an external appendage chosen the conjugation hair.[31] Bacterial conjugation is controlled by plasmid genes that are adjusted for spreading copies of the plasmid betwixt leaner. The infrequent integration of a plasmid into a host bacterial chromosome, and the subsequent transfer of a part of the host chromosome to another prison cell do not announced to be bacterial adaptations.[13] [32]

Exposure of hyperthermophilic archaeal Sulfolobus species to Deoxyribonucleic acid damaging conditions induces cellular aggregation accompanied by high frequency genetic mark substitution.[33] [34] Ajon et al.[34] hypothesized that this cellular aggregation enhances species-specific Dna repair by homologous recombination. Dna transfer in Sulfolobus may be an early course of sexual interaction like to the more well-studied bacterial transformation systems that besides involve species-specific Deoxyribonucleic acid transfer leading to homologous recombinational repair of DNA harm.

Meet also [edit]

  • Amphimixis (psychology)
  • Anisogamy
  • Biological reproduction
  • Hermaphroditism
  • Isogamy
  • Mate choice
  • Mating in fungi
  • Operational sexual activity ratio
  • Outcrossing
  • Allogamy
  • Self-incompatibility
  • Sex
  • Sexual intercourse
  • Transformation (genetics)

References [edit]

  1. ^ John Maynard Smith & Eörz Szathmáry, The Major Transitions in Evolution, West. H. Freeman and Company, 1995, p 149
  2. ^ "Fertilization". Merriam-Webster. Retrieved 2013-11-03 .
  3. ^ a b Otto, Sarah P.; Lenormand, Thomas (1 April 2002). "Resolving the paradox of sex and recombination". Nature Reviews Genetics. 3 (4): 252–261. doi:ten.1038/nrg761. PMID 11967550. S2CID 13502795.
  4. ^ John Maynard Smith The Evolution of Sex 1978.
  5. ^ Ridley M (2004) Development, 3rd edition. Blackwell Publishing, p. 314.
  6. ^ Hussin, Julie G; Hodgkinson, Alan; Idaghdour, Youssef; Grenier, Jean-Christophe; Goulet, Jean-Philippe; Gbeha, Elias; Hip-Ki, Elodie; Awadalla, Philip (2015). "Recombination affects accumulation of dissentious and disease-associated mutations in human populations". Nature Genetics. 47 (4): 400–404. doi:ten.1038/ng.3216. PMID 25685891. S2CID 24804649. Lay summary (iv March 2015).
  7. ^ Cecie Starr (2013). Biology: The Unity & Diversity of Life (Ralph Taggart, Christine Evers, Lisa Starr ed.). Cengage Learning. p. 281.
  8. ^ Vogt, Yngve (January 29, 2014). "Large testicles are linked to adultery". Phys.org . Retrieved January 31, 2014.
  9. ^ Agrawal, A. F. (2001). "Sexual selection and the maintenance of sexual reproduction". Nature. 411 (6838): 692–5. Bibcode:2001Natur.411..692A. doi:10.1038/35079590. PMID 11395771. S2CID 4312385.
  10. ^ N.J. Butterfield (2000). "Bangiomorpha pubescens n. gen., n. sp.: implications for the evolution of sex, multicellularity, and the Mesoproterozoic/Neoproterozoic radiation of eukaryotes". Paleobiology. 26 (iii): 386–404. doi:10.1666/0094-8373(2000)026<0386:BPNGNS>2.0.CO;ii. S2CID 36648568.
  11. ^ T.M. Gibson (2018). "Precise age of Bangiomorpha pubescens dates the origin of eukaryotic photosynthesis". Geology. 46 (ii): 135–138. Bibcode:2018Geo....46..135G. doi:10.1130/G39829.i.
  12. ^ Gray, J. C.; Goddard, Thou. R. (2012). Bonsall, Michael (ed.). "Gene-menstruum betwixt niches facilitates local adaptation in sexual populations". Ecology Letters. xv (ix): 955–962. doi:10.1111/j.1461-0248.2012.01814.x. PMID 22690742.
  13. ^ a b c Michod RE, Bernstein H, Nedelcu AM; Bernstein; Nedelcu (May 2008). "Adaptive value of sexual practice in microbial pathogens" (PDF). Infect. Genet. Evol. 8 (3): 267–85. doi:x.1016/j.meegid.2008.01.002. PMID 18295550. {{cite periodical}}: CS1 maint: multiple names: authors list (link)
  14. ^ a b Bernstein, Harris; Bernstein, Carol (2010). "Evolutionary Origin of Recombination during Meiosis". BioScience. lx (7): 498–505. doi:10.1525/bio.2010.60.7.v. S2CID 86663600.
  15. ^ a b Bernstein H, Bernstein C, Michod RE. (2012) "DNA Repair as the Primary Adaptive Office of Sexual activity in Leaner and Eukaryotes Archived 2013-10-29 at the Wayback Machine". Chapter 1, pp. one–50, in Dna Repair: New Research, Editors South. Kimura and Shimizu Due south. Nova Sci. Publ., Hauppauge, New York. Open up access for reading only. ISBN 978-1-62100-756-2
  16. ^ Colegrave, Due north (2002). "Sexual activity releases the speed limit on evolution". Nature. 420 (6916): 664–vi. Bibcode:2002Natur.420..664C. doi:10.1038/nature01191. hdl:1842/692. PMID 12478292. S2CID 4382757.
  17. ^ Kleiman, Maya; Tannenbaum, Emmanuel (2009). "Diploidy and the selective advantage for sexual reproduction in unicellular organisms". Theory in Biosciences. 128 (4): 249–85. arXiv:0901.1320. doi:10.1007/s12064-009-0077-ix. PMID 19902285. S2CID 1179013.
  18. ^ Dimijian, One thousand. G. (2005). Evolution of sexuality: biological science and behavior. Proceedings (Baylor University. Medical Center), 18, 244–258.
  19. ^ Reichard, U.H. (2002). "Monogamy—A variable human relationship" (PDF). Max Planck Research. 3: 62–7. Archived from the original (PDF) on 24 May 2013. Retrieved 24 Apr 2013.
  20. ^ Lipton, Judith Eve; Barash, David P. (2001). The Myth of Monogamy: Fidelity and Infidelity in Animals and People. San Francisco: Due west.H. Freeman and Company. ISBN0-7167-4004-four.
  21. ^ Enquiry conducted by Patricia Adair Gowaty. Reported by Morell, V. (1998). "Evolution of sex: A new wait at monogamy". Science. 281 (5385): 1982–1983. doi:10.1126/science.281.5385.1982. PMID 9767050. S2CID 31391458.
  22. ^ "BONY FISHES - Reproduction". Archived from the original on 2013-10-03. Retrieved 2008-02-11 .
  23. ^ M. Cavendish (2001). Endangered Wild animals and Plants of the World. Marshall Cavendish. p. 1252. ISBN978-0-7614-7194-three . Retrieved 2013-11-03 .
  24. ^ Orlando EF, Katsu Y, Miyagawa Southward, Iguchi T; Katsu; Miyagawa; Iguchi (2006). "Cloning and differential expression of estrogen receptor and aromatase genes in the cocky-fertilizing hermaphrodite and male mangrove rivulus, Kryptolebias marmoratus". Journal of Molecular Endocrinology. 37 (ii): 353–365. doi:10.1677/jme.ane.02101. PMID 17032750. {{cite journal}}: CS1 maint: multiple names: authors list (link)
  25. ^ I. Schlupp, J. Parzefall, J. T. Epplen, Grand. Schartl; Parzefall; Epplen; Schartl (2006). "Limia vittata as host species for the Amazon molly: no evidence for sexual reproduction". Journal of Fish Biology. 48 (four): 792–795. doi:ten.1111/j.1095-8649.1996.tb01472.x. {{cite journal}}: CS1 maint: multiple names: authors list (link)
  26. ^ Judd, Walter S.; Campbell, Christopher S.; Kellogg, Elizabeth A.; Stevens, Peter F.; Donoghue, Michael J. (2002). Plant systematics, a phylogenetic approach (ii ed.). Sunderland MA, United states: Sinauer Assembly Inc. ISBN0-87893-403-0.
  27. ^ Poinar Jr., George O; Chambers, Kenton Fifty; Wunderlich, Joerg (x December 2013). "Micropetasos, a new genus of angiosperms from mid-Cretaceous Burmese amber". J. Bot. Res. Inst. Texas. 7 (two): 745–750. Archived from the original (PDF) on five January 2014.
  28. ^ Jon Lovett Doust; Lesley Lovett Doust (1988). Plant Reproductive Environmental: Patterns and Strategies. Oxford University Press. p. 290. ISBN9780195063943.
  29. ^ a b Wallen RM, Perlin MH (2018). "An Overview of the Function and Maintenance of Sexual Reproduction in Dikaryotic Fungi". Front Microbiol. nine: 503. doi:10.3389/fmicb.2018.00503. PMC5871698. PMID 29619017.
  30. ^ Lorenz, MG; Wackernagel, West (1994). "Bacterial gene transfer by natural genetic transformation in the environment". Microbiological Reviews. 58 (iii): 563–602. doi:x.1128/mmbr.58.iii.563-602.1994. PMC372978. PMID 7968924.
  31. ^ Lodé, T (2012). "Have Sex activity or Not? Lessons from Bacteria". Sexual Evolution : Genetics, Molecular Biology, Evolution, Endocrinology, Embryology, and Pathology of Sex Determination and Differentiation. half dozen (6): 325–8. doi:10.1159/000342879. PMID 22986519.
  32. ^ Krebs, JE; Goldstein, ES; Kilpatrick, ST (2011). Lewin's GENES Ten. Boston: Jones and Bartlett Publishers. pp. 289–292. ISBN9780763766320.
  33. ^ Fröls S, Ajon Grand, Wagner M, Teichmann D, Zolghadr B, Folea G, Boekema EJ, Driessen AJ, Schleper C, Albers SV (2008). "UV-inducible cellular assemblage of the hyperthermophilic archaeon Sulfolobus solfataricus is mediated past pili formation" (PDF). Mol Microbiol. 70 (4): 938–952. doi:10.1111/j.1365-2958.2008.06459.x. PMID 18990182. S2CID 12797510.
  34. ^ a b Ajon M, Fröls S, van Wolferen M, Stoecker K, Teichmann D, Driessen AJ, Grogan DW, Albers SV, Schleper C; Fröls; Van Wolferen; Stoecker; Teichmann; Driessen; Grogan; Albers; Schleper (Nov 2011). "UV-inducible DNA exchange in hyperthermophilic archaea mediated by blazon Iv pili" (PDF). Mol. Microbiol. 82 (four): 807–17. doi:10.1111/j.1365-2958.2011.07861.10. PMID 21999488. S2CID 42880145. {{cite journal}}: CS1 maint: multiple names: authors list (link)

Farther reading [edit]

  • Pang, Yard. "Certificate Biology: New Mastering Basic Concepts", Hong Kong, 2004
  • Journal of Biological science of Reproduction, accessed in August 2005.
  • "Sperm Use Heat Sensors To Find The Egg; Weizmann Institute Research Contributes To Understanding Of Human Fertilization", Scientific discipline Daily, 3 Feb 2003
  • Michod, RE; Levin, Exist, eds. (1987). The Evolution of sex: An examination of current ideas . Sunderland, Massachusetts: Sinauer Associates. ISBN978-0878934584.
  • Michod, RE (1994). Eros and Evolution: A Natural Philosophy of Sex. Perseus Books. ISBN978-0201407549.

External links [edit]

  • Khan Academy, video lecture

Source: https://en.wikipedia.org/wiki/Sexual_reproduction

Posted by: petershilestered.blogspot.com

Related Posts

0 Response to "In Plants And Animals, The Zygote Develops Into An Embryo By What Process?"

Post a Comment

Subscribe to: Post Comments (Atom)

Iklan Atas Artikel

Iklan Tengah Artikel 1

Iklan Tengah Artikel 2

Iklan Bawah Artikel