Soil
Soil is the upper layer of the ground comprising of a mixture of sand, silt, clay, loose rock fragments, and organic matter that can support the growth of rooted plants. The relative proportions of sand, silt and clay determine the texture and size of the pores of the soil, which affects its ability to allow air and water to penetrate/infiltrate.
Population because you are holding it
A cell membrane pump helps human cells to maintain a relatively constant sodium and potassium concentration.
<u>Option: A</u>
<u>Explanation:</u>
Sodium potassium pump is a plasma membrane protein that utilizes energy ATP — Triphosphate Adenosine turning into ADP — Adenosine Diphosphate to deliver intracellular and extracellular sodium (NA+) and potassium (K+) ions sequentially. The purpose of this entire mechanism is to preserve cell equilibrium.
The extracellular medium has a greater concentration of Na while the K concentration of the intracellular fluid is lower. Proteins trap sodium ions in the cytoplasm and pump them out from the cells to preserve cell stability while preserving concentrations. Within the cells proteins inject potassium ions into the cell.
Answer:
Answer is option D.
Flowers contain parts for making seeds.
Explanation:
The part of the plant that is responsible for the sexual reproduction in plants is known as flowers. A flower is said to be complete if contains sepals, petals, stamens and pistil. If the flower lacks one or more structures, it is an incomplete flower.
A complete flower consists of a vegetative part and a reproductive part. The vegetative part contains petals (a bright coloured structure that attracts insects and birds) and sepals (a green coloured structure that protects rising buds and is usually found beneath the petals). The reproductive parts include stamen or androecium (male reproductive organ) and pistil (female reproductive organ). A flower may consists of only female parts or only male parts, or both.
Stamen contains two parts - anther, which produce and store the pollens (male gametes) and filament, which support the anther. Pistil contains three parts - stigma, which receives the pollen grains and style that connects stigma and the ovary, and ovary which contains a lot of ovules (female gametes) which forms the seed.
Flowers reproduce by pollination, a process in which the pollen are transferred to the stigma of another flower. A pollen tube emerges from the pollen grain and grows through the style and reaches an ovule inside the ovary. Then the nucleus of the pollen grain passes through the pollen tube and fuses with the nucleus of the ovule and this process is known as fertilisation. The fertilised ovules become seeds and the ovary transforms into the fruit. The seeds are dispersed through various methods and the embryo inside them will grow into adult plants.
