Answer:
On his visit to the Galapagos Islands, Charles Darwin discovered several species of finches that varied from island to island, which helped him to develop his theory of natural selection.
Darwin's finches are a classical example of an adaptive radiation. Their common ancestor arrived on the Galapagos about two million years ago. During the time that has passed the Darwin's finches have evolved into 15 recognized species differing in body size, beak shape, song and feeding behaviour.
Answer:
Increasing the alveolar ventilation rate will increase the partial pressure of oxygen in the alveoli.
Explanation:
Alveolar Ventilation rate is the rate of air flow in the alveoli of the lung during normal breathing. It is measured in milliliters of air per minute (mL/min). The alveolar ventilation rate is an important factor in determining the concentrations (partial pressures) of oxygen and carbon dioxide in the functioning alveoli.
A high rate of alveolar ventilation, would result in a rapid influx of oxygen-rich air and efflux carbon dioxide-filled air from the alveoli. This ultimately results in an increase in the concentration of oxygen and a decrease in the concentration of carbon dioxide within the alveoli.
Effects of alveolar ventilation on partial pressures of alveolar carbon dioxide and oxygen (PACO₂ and PAO₂)
If the alveolar ventilation rate is increased (and carbon dioxide production is unchanged), then the partial pressure of carbon dioxide in the alveoli, PACO₂ will decrease.
If the alveolar ventilation rate increases, then the partial pressure of oxygen in the alveoli, PAO₂ will increase.
Answer:
This question lacks options, the options are:
A. All 270 tall plants were heterozygous
B. All 270 tall plants were homzygous.
C. Only 90 plants were homzygous.
D. All dwarf plants were homzygous.
The answer is D.
Explanation:
This question involves a single gene coding for height in pea plants. The allele for tallness (T) is dominant over that of dwarfness (t). This means that a dwarf plant can only be homzygous recessive (tt) while a tall plant can either be homzygous (TT) or heterozygous (Tt).
According to the question, two tall heterozygous pea plants were crossed i.e. Tt × Tt. Based on this cross, a phenotypic ratio of 3:1 is expected, which is in accordance with the 270 tall plants and 90 dwarf plants (360 total) that was obtained in the cross. Since dwarfism in pea plants is a recessive trait, this means that all the dwarf plants produced in this cross (90) were homzygous (tt).
Answer: C) The event at the end of the Triassic Resulted in the extinction of fewer fauna’s then in any other period
Explanation:
Looking at the graph, the event at the end of the Triassic resulted in the smallest dip in the amount of fauna in the graph. This means that this event resulted in the extinction of fewer faunas than any of the other five major events.
Option A is wrong as the event at the end of the Devonian decreased the number of Cambrian fauna.
Option B is wrong as the event at the end of the Cretaceous resulted in a decrease in the Paleozoic fauna.
Option D is wrong because the event that resulted in the Extinction of more fauna’s then in any other period was the event at the end of the Permian.
