The randomness in the alignment of recombined chromosomes at the metaphase plate, coupled with the crossing over events between nonsister chromatids, are responsible for much of the genetic variation in the offspring. To clarify this further, remember that the homologous chromosomes of a sexually reproducing organism are originally inherited as two separate sets, one from each parent. Using humans as an example, one set of 23 chromosomes is present in the egg donated by the mother. The father provides the other set of 23 chromosomes in the sperm that fertilizes the egg. Every cell of the multicellular offspring has copies of the original two sets of homologous chromosomes. In prophase I of meiosis, the homologous chromosomes form the tetrads. In metaphase I, these pairs line up at the midway point between the two poles of the cell to form the metaphase plate. Because there is an equal chance that a microtubule fiber will encounter a maternally or paternally inherited chromosome, the arrangement of the tetrads at the metaphase plate is random. Thus, any maternally inherited chromosome may face either pole. Likewise, any paternally inherited chromosome may also face either pole. The orientation of each tetrad is independent of the orientation of the other 22 tetrads.
Explanation:
Answer:
(d) Nematoda.
Explanation:
Pseudocoelomate organisms are animals that possess a pseudocoelom (not a true coelom). A perfect example of animals that are pseudocoelomate are those that belong to the phylum Nematoda. They include roundworms, hookworms etc. A pseudocoelom is a cavity containing fluid which immerses the internal organs of a nematode.
Their physical structure is triploblastic and bilaterally symmetrical. They have two body openings that links to their digestive system, but do not possess a stomach.
Animals that belongs to phylum Arthropoda are coelomate organisms, meaning they possess.
Animals that belongs to phylum Cnidaria are acoelomate organisms, meaning they do not posses coelom.
Animals that belongs to phylum Porifera are acoelomate organisms.
If a long-day plant has a critical night length of 9 hours, a 24 -hour cycle of 14 hours light / 10 hours dark would prevent flowering.
Flowering plants are plants that bear flowers and fruits and form clade angiosperms, commonly called angiosperms.
The term “angiosperm” is derived from the Greek angeion (“vessel”) and sperma (“seed”) and refers to plants that produce seeds that are encased in fruit.
By far the most diverse group of land plants, with 64 orders, 416 families, about 13,000 known genera, and 300,000 known species. In earlier days, angiosperms were also called Magnoliophyta.
Many flowers have bright colors, strong scents and sweet nectar to attract pollinators. It can attract insects, birds, mammals and even reptiles.
When visiting flowers, pollinators pick up pollen from the anthers. When pollinators visit the next flower, some of the pollen sheds the stigma. This allows for cross-pollination and increases genetic diversity.
Learn more about Flowering here : brainly.com/question/91296
#SPJ4
Explanation:
The allele combination would most likely be xx if recessive
The reactive CARBONYL GROUP, contributes to the ability of aldehydes and ketones to be involved in energy reactions. Aldehydes and ketones undergo different types of reactions that lead to various products. One example of these reactions are nucloephilic reactions which lead to the production of alcohols, alkenes, diols, imine, etc.
