3) C. Stomata, as I explained in my previous answer.
4) B. Nonvascular, low-hanging plants living in moist environs don't have to fight gravity nearly as much as tall ones do. So they needn't highly developed vessels to transport to their tips
5) B. Gravity, see above. The higher trees/plants grew, the further their apical structures were from ground water sources, so the lignin-supported, strong vascular tissue (phloem) allows the transport of water against gravity, using a capillary method (benefiting from the adhesive effect of water molecules).
Answer:
The correct answer would be a lipid-soluble signal.
Signal transduction refers to the set or cascade of bio-chemical reactions take place in a cell in order to transmit the chemical or physical signal from outside the cell to inside target molecule.
It is usually initiated by receptors present on the membrane of the cell which sense the extracellular stimulus (such as ligand, hormone, pressure, temperature, pressure etc). Once activated, these receptors activate the cascade of reaction which ultimately reaches the target molecule and produces a cell's response.
In contrast, the lipid-soluble signals (such as steroidal hormones, thyroid hormone etc) enter the cell membrane without any hindrance. They directly bind to intra-cellular receptor present in the cytoplasm or on the nuclear membrane.
The hormone-receptor complex then enters the nucleus and act as transcription factor and produces the response in the form of transcription.
Answer;
When we will travel south from a taiga into a temperate forest we will observe 1. Increased precipitation as in taiga the prevailing climatic conditions are still harsh with less rain fall where as in temperate forest precipitation ranges from about 70 to 150 cm annually. 2. Increase in temperature as taiga has long, severe winters and short, mild summers whereas the average temperature in temperate forest is around 50 degree Celsius. 3. Change towards hardwood (deciduous) trees as Taiga, forms an almost continuous belt of coniferous trees worldwide whereas Temperate or deciduous forests are dominated by broad-leaved hardwood trees
Answer:
b. Mitochondrial respiration
Explanation:
Mitochondrial respiration of plants involves the participation of two major electron transport routes:
1. Cytochrome c oxidase route: cyanide sensitive and coupled to three energy conservation sites.
2. Cyanide-insensitive alternative route: involves alternative oxidase (AOX), branches off the cytochrome oxidase route into the ubiquinone pool, with no energy conservation thereafter as AOX is able to directly oxidize ubiquinol and reduce oxygen to water.
Regardless of the route followed, mitochondrial breathing is a long and complex process. However, it is through this breath that at a given moment electrons are passed to oxygen through a carrier channel in the inner mitochondrial membrane. This happens when cytochromes to and some molecules that have a heme group (with an iron atom) and are linked to a transmembrane protein that connects the matrix to the mitochondrial intermembrane space and have two copper atoms that allow the transport of electrons to the final acceptor, oxygen (O2).
