Answer:
respiration, waste production, food intake, cells, breathing
D. is the non-random change in allele frequencies that occurs in a small population.
Answer:
The person has been dead for approximately 15,300 years
Explanation:
<u>Available data</u>:
- The half-life of carbon 14 is 5,600 years
- The human skeleton level of carbon 14 is 15% that of a living human
To answer this question we can make use of the following equation
Ln (C14T₁/C14 T₀) = - λ T₁
Where,
- C14 T₀ ⇒ Amount of carbon in a living body at time 0 = 100%
- C14T₁ ⇒ Amount of carbon in the dead body at time 1 = 15%
- λ ⇒ radioactive decay constant = (Ln2)/T₀,₅
- T₀,₅ ⇒ The half-life of carbon 14 = 5600 years
- T₀ = 0
- T₁ = ???
Let us first calculate the radioactive decay constant.
λ = (Ln2)/T₀,₅
λ = 0.693/5600
λ = 0.000123
Now, let us calculate the first term in the equation
Ln (C14T₁/C14 T₀) = Ln (15%/100%) = Ln 0.15 = - 1.89
Finally, let us replace the terms, clear the equation, and calculate the value of T₁.
Ln (C14T₁/C14 T₀) = - λ T₁
- 1.89 = - 0.000123 x T₁
T₁ = - 1.89 / - 0.000123
T₁ = 15,365 years
The person has been dead for approximately 15,300 years
Answer;
B) Neurons, epithelial cells
Explanation;
-Primary lateral sclerosis (PLS) is a rare neuromuscular disease with slowly progressive weakness in voluntary muscle movement. PLS belongs to a group of disorders known as motor neuron diseases. PLS affects the upper motor neurons (also called corticospinal neurons) in the arms, legs, and face.
-It occurs when nerve cells in the motor regions of the cerebral cortex (the thin layer of cells covering the brain which is responsible for most higher level mental functions) gradually degenerate, causing movements to be slow and effortful. The disorder often affects the legs first, followed by the body, trunk, arms and hands, and, finally the bulbar muscles (muscles that control speech, swallowing, and chewing).
Answer:
4
Explanation:
According to newton's second law f=ma. so a =f/m
then a=20/5 gives 4