Answer:   
Cane toads were introduced intentionally in Australia in 1935 to combat cane beetles in the sugar cane crop fields. These toads exhibit higher feeding capacity. These can feed not only cane beetles but other insects which affecting agricultural yields. They are poisonous in nature, they kill any insect after ingestion. Therefore, they are useful biological insecticide which provides crops resistance against insects. 
 
        
                    
             
        
        
        
Answer:
The t-test 
Explanation:
<em>The researcher should use a t-test to compare the two means and check if they are significantly different from each other.</em>
In using the t-test, both null (H0) and alternate (H1) hypothesis are made such that:
Thereafter, the value of t is calculated and compared to its critical value on the table. The formula for calculating the t goes thus:
  
 
where, Y1 = mean of population 1, Y2 = mean of population 2, S1 = variance of population 1, S2 = variance of population 2, n1 = number of individuals in population 1 and s2 = number of individuals in population 2.
<em>At the end of the day, if the calculated t value is more than the critical value of t, the H0 is rejected and it shows that the two means are significantly different. Otherwise, the H0 is accepted and this shows that there is not significant difference between the mean of population 1 and that of 2.</em>
 
        
             
        
        
        
Answer:
It will die.
Explanation:
Fish need functional gills to live.
 
        
             
        
        
        
Answer:
rocks can be smooth ridged or sharp
Explanation:
 there rocks and they can form differently
 
        
             
        
        
        
<u>Definition:</u>
The sex hormone  and endogenous steroid present in human and other species ' menstrual cycle, pregnancy, and embryogenesis are known as "Progesterone" while the primary sex hormone in females  responsible for the development and control of the female reproductive system and for the characteristics of secondary sex is termed as "Estrogen" or "oestrogen".
<u>Progesterone Effects:</u>
- Progesterone has a variety of physiological effects which are exacerbated when estrogens are present for an instance in breast tissue, where estrogens permits progesterone to mediate lobuloalveolar development.
- Progesterone has main effects on human sperm by non-genomic signals, as they move through the female tract before fertilization.
- Progesterone is called "hormone of pregnancy" as transform the endometrium to its secretory stage for uterine implantation, decrease the maternal immune response to permit for the acceptance of the pregnancy during implantation and gestation, prevent preterm labor, inhibits lactation during pregnancy etc.
<u>Estrogen Effects:</u>
- Effects structure of human and categorize them as male and female, while females have three kind of estrogen: Estrone (weak and found in women after menopause), Estradiol (strong and it is steroid produced by ovaries ) and Estriol (weakest and waste product after body produces estradiol).
- It effects ovaries, vagina, Fallopian tube, uterus, cervix and mammary glands.
- It triggers the release of an egg due to high level during halfway of cycle but decreases after ovulation.
<u>Similarities between progesterone and estrogen: </u>
Progesterone and estrogen  as such do not have similar function but work with coordination as both are need for menstrual cycle functioning and regulation. Estrogens usually travel in fluids through the bloodstream, communicate with cells in the body's various tissues, and provide a message or guidance while progesterone helps to balance pregnancy period  and to implant an egg in uterus.