The defecation reflex involves two postive feedback loops. these loops are the stretch receptors in the rectal walls and the sacral parasympathetic system. Defecation reflex empties the rectum by peristaltic movements push fecal matter from the sigmoid colon into the rectum. Then this distension of the rectal walls stimulates stretch receptors which results in defecation.
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Shadows are made by blocking light. Light rays travel from a source in straight lines. If an opaque (solid) object gets in the way, it stops light rays from traveling through it. This results in an area of darkness appearing behind the object. The dark area is called a shadow
Answer:
The correct answer is-
Hypothesis: Antibiotics cause weight gain in cows.
Independent Variable: Antibiotic pill
Dependent Variable: Weight of cow
Control Group: a group of cows gets a placebo pill
Experimental Group: a group of cows gets an antibiotic pill
Explanation:
The Independent variable is the variable that causes the response from the dependent variable or affects the dependent variable in this study the antibiotic pill affects the weight of cows so The independent variable is an antibiotic pill and the dependent variable is the weight of cows.
The control group is the group of subjects that did not get the treatment in a scientific study in the case of this study group of cows that receives the placebo pill is the control group and the experiment group is subjects that receive the treatment which is a group with the antibiotic pill.
Answer:
The pollen grain is creating a tube down the style of the flower. <u>It is necessary as that is how the pollen is able to travel down the style into the ovary where the baby seed is located. This is how the seed is fertilized, and is ready for reproduction.</u>
Answer:
Fertilizers are the chemicals that are applied on the agricultural crops to increase the yield of crop and protect them from harmful pests. The fertilizers are rich in nitrogen, phosphorus and potassium.
Karen and Jimmy growing tomato to conduct the research. They conclude that large amount of fertilizer is helpful for plant growth. This is wrong because high fertilizer can decrease the plant growth and may cause the death of plant. The fertilizers are required in the exact amount in the plants and there inappropriate level inhibits the plant growth.