Answer: Alarm reaction stage
Explanation:
The General Adaptation Syndrome (GAS) is the 3- stage body response to stress conditions. The three stages include
1) Alarm reaction stage
2) Resistance stage
3) Exhaustion stage
Note that the Alarm reaction stage consist of arousal by the autonomic nervous system, where several involuntary responses such as sweating, tension, raised breathing etc are observed due to hormones released.
<span>Microevolution refers to changes in the genetic pool
of a species population. The changes in the genes (probably gene and allele frequencies)
are observed over short time periods hence are small changes. This is in comparison
to macroevolution that observes huge changes over longer time periods in the population that warrant that the new populations
is considered to be a new species</span>
<span>Corticotropin-releasing factor is produced by the anterior pituitary, hypothalamus, adrenal glands, and ovaries. It is a hormone released in response to stress. Secretion has been seen to be higher in patients with depression and Alzheimer's disease. In addition to the aforementioned, CRF is secreted in lymphocytes and the placenta.</span>
Answer: These may be:
- physical defenses (1st line)
- chemical defenses (2nd line)
Explanation:
Plants employ several methods in order to defend themselves from pathogens. These may be physical defenses or chemical ones. Several have adaptations to their surfaces that prevent the entry of pathogens, called physical barriers such as
- thick waxy cuticles
- thorns, which are modified plant branches
- spines, which are modified plant leaves
- gall production at infected sites to prevent pathogenic spread
Chemical defenses include the production or secretion of:
- defensins
- antimicrobials such as tannins or resins
- gum at areas facing pathogenic attacks
