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11 de ene. de 2023 · For many people, hair is a natural part of their look and an expression of their personality. Hair can also offer protection: For instance, it helps to keep the sun’s rays from reaching our scalp. Eyelashes and eyebrows keep dust, dirt and sweat out of our eyes. Even the hairs in our nose and ears help to keep out germs and other foreign objects. Body hair helps to regulate our body ...
(A) Diagramof one of the two ovary chambers after removal of the ovary wall (OW).Pollen lands on the stigma, where it hydrates, germinates, and extends a tube that enters the transmittingtract (rr). The tube emerges onto the septum (S), grows up the funiculus(f),and enters the micropyleopening of the ovule (O),where it fertilizesthe egg and central cell.
4 de sept. de 2018 · The ovary is the gonadal organ (primary sexual organ) in females. There are two ovaries located within the pelvic cavity, on either side of the uterus. Ovaries contain the developing follicles which produce human egg cells (ova/oocytes) in a cyclic manner, and are also responsible for the secretion of some important hormones such as estrogen ...
Define double fertilization. In angiosperms, pollination is defined as the placement or transfer of pollen from the anther to the stigma of the same flower or another flower. In gymnosperms, pollination involves pollen transfer from the male cone to the female cone. Upon transfer, the pollen germinates to form the pollen tube and the sperm for ...
The ovaries have two main reproductive functions in the body. They produce oocytes (eggs) for fertilisation and they produce the reproductive hormones, oestrogen, progesterone and androgens. The function of the ovaries is controlled by gonadotrophin-releasing hormone (GnRH) released from the hypothalamus which in turn stimulates the pituitary ...
Define double fertilization. In angiosperms, pollination is defined as the placement or transfer of pollen from the anther to the stigma of the same flower or another flower. In gymnosperms, pollination involves pollen transfer from the male cone to the female cone. Upon transfer, the pollen germinates to form the pollen tube and the sperm for ...
Following fertilization, seeds may mature in as short a time as one year but for most species it is two years or longer. In most pines, the cones eventually re-open, allowing the seeds to fall out and be dispersed by the wind. Sometimes the cones remained closed and only open following the intense heat of a fire.
