Answer:
The correct option is <u>B. Lipids</u>
Explanation:
Lipids can be described as molecules which dissolve in non-polar solvents and cannot dissolve in water. The biological function of a lipid molecule is to store energy as well as to structure the shape of cell membranes. Lipids are also used in a cell for signalling.
Lipids are made up of carbon, hydrogen and oxygen. Some lipids might have phosphorus in them like the phospholipids which make up the cell membrane.
Q1. The answer is 1.
It can be calculated using the equation:
(1/2)ⁿ = x
x - decimal amount remaining,
n - a number of half-lives.
x = 50% = 50/100 = 0.5
n = ?
(1/2)ⁿ = 0.5
log((1/2)ⁿ) = log(0.5)
n * log(1/2) = log(0.5)
n * log(0.5) = log(0.5)
n = log(0.5)/log(0.5)
n = 1
Q10. The answer is 2.
It can be calculated using the equation:
(1/2)ⁿ = x
x - decimal amount remaining,
n - a number of half-lives.
Rhyolite #2 has 25% of the parent H remaining:
x = 25% = 25/100 = 0.25
n = ?
(1/2)ⁿ = 0.25
log((1/2)ⁿ) = log(0.25)
n * log(1/2) = log(0.25)
n * log(0.5) = log(0.25)
n = log(0.25)/log(0.5)
n = -0.602 / - 0.301
n = 2
Q3. The answer is 100 million years.
A number of half-lives (n) is a quotient of total time elapsed (t) and length of half-life (H):
n = t/H
n = 1
t = ?
H = 100 000 000 years
n = t/H
t = n * H
t = 1 * 100 000 000 years
t = 100 000 000 years<span>
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Answer:
Species separated by a physical barrier for a long time, suffer allopatric speciation, so they can not interbreed anymore.
Explanation:
Allopatric speciation consists of the geographic separation of a continuous genetic background giving place to two or more new geographically isolated populations. These separations might be due to migration, extinction of geographically intermediate populations, or geological events. In this speciation, some barriers impede genetic interchange, or genetic flow, as the two new populations that are separated can not get together and mate anymore. These barriers might be geographical or ecological.
Vicariance is the geographical separation of an original population into two or more new groups. Discontinuities in the physical environment like rivers, mountains, water, etc., are physical barriers that impede genetic flow between the separated groups.
The process of allopatric speciation involves different steps:
- The emergence of the barrier.
- Interruption in the genetic interchange
- The occurrence of new mutations and their accumulation in time in each population. Slow and gradual differentiation.
- Genetic divergence by natural selection and reproductive isolation makes it impossible for the two groups to mate even if the barrier disappears.
- Prezigotic isolation mechanisms favored by selection once occurs a secondary contact between the new species in formation.
Human migration is the movement over long distances, movement from one country/region to another ) by people . Humans moved because of the c<span>hanging climate and landscape and inadequate food supply. </span>The first human movement was t<span>he movement of </span>Homo erectus<span> out of Africa across </span>Eurasia<span> about 1.75 million years ago. </span>
Than industrialization<span> encouraged migration wherever it appeared.
Wars also created migration. (</span><span>The First and Second World Wars, and wars, genocides, and crises sparked by them, lead to migrations).</span>
