Search results for: 'Diploid organisms'

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By: HWC, Views: 503

Diploid organisms have pairs of genes, on pairs of homologous chromosomes. Each gene has a specific location on the chromosome. We call this the gene's locus. In this species, the locus for gene B is always between the loci for genes A and C. Most genes come in two or more slightly differen...

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Generalized life cycles for plants and animals Animation

By: HWC, Views: 477

But the life cycles of plants and animals differ in their details. In animals, a multicelled diploid stage gives rise to single-celled haploid gametes, the eggs and sperm. These gametes combine at fertilization to form a diploid zygote, which grows and develops into a new multicelled animal...

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Egg and Sperm Formations in Animals Animation

By: HWC, Views: 457

Inside the ovaries of a female animal are diploid germ cells called oogonia. An oogonium grows to become a primary oocyte. This large cell is still diploid. Meiosis I followed by unequal cytoplasmic division produces one large secondary oocyte and a smaller polar body. Both are haploid. ...

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Darwin's Observation (Fossils, Galapagos Islands & Africa ) and Natural Selection (Adaptive Traits)

By: HWC, Views: 6556

Along Darwin's voyage, he made many observations. Each one added to his understanding of how organisms change over time. Darwin was already familiar with fossils and knew that many fossils were very different from living organisms. But, also there were some fossils that were very similar to li...

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Sperm Formation

By: HWC, Views: 4604

Spermatogenesis takes place inside the seminiferous tubules. Diploid spermatogonia located near the outer edge of the tubule divide mitotically to form primary spermatocytes. The first meiotic division produces secondary spermatocytes with a haploid number of duplicated chromosomes. T...

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Red alga life cycle Animation

By: HWC, Views: 885

Life cycle of Porphyra. The most conspicuous part of this algal life cycle is the haploid gametophyte. This sheetlike form is collected and dried for use as nori, the wrapping for sushi. Gametes form in packets interspersed between vegetative cells near the sheet margins. The gamet...

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Ciliate conjugation Animation

By: HWC, Views: 1027

Protozoan conjugation is an unusual form of sexual reproduction Prospective partners join together, usually at the surface of their oral depressions. The cells undergo cytoplasmic fusion. Meiosis II produces four haploid micronuclei. Now the macronucleus of each cell begins to bre...

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Green alga life cycle Animation

By: HWC, Views: 1252

Chlamydomonas zoospores are haploid flagellated cells. As long as conditions are favorable, these cells reproduce asexually. As many as sixteen cells may form by mitosis within a parent cell. Daughter cells escape when the cell wall ruptures. When conditions become less favorable, the...

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Energy Flow - Trophic Levels and Food

By: HWC, Views: 6213

All of these relationships between different species are founded on one thing: energy. Organisms get food in order to get energy, which is used by the organism for growth, maintaining health, and reproduction. We can classify the members of a community according to how they obtain food. Produc...

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