Answer: B: Changes in gene expression help Rudbeckia hirta adjust to its environment.
Explanation: I just took this test :) this was the right one... the gradual decline shown shows a change in expression, resulting in fewer stomata, as the environmetal conditions change.
Answer:
The correct option is <em><u>A. Over time, due to evolution by means of natural selection, resistant weeds survived, reproduced, and passed on their herbicide resistant genes. </u></em>
Explanation:
Herbicides can be described as substances which are used to kill unwanted plants such as the weeds. Nowadays, selective herbicides are produces which are effective in killing the weed species and do not harm the crop plants.
But over time, the weeds get resistant to the herbicide. As the theory of natural selection says, 'survival of the fittest', the herbicide which are resistant are better adapted to live hence, they pass their genes to the offsprings. This results in the production of more herbicide resistant weeds.
Answer:
1938
Explanation:
Matthias Schleiden was a German botanist who studied the plant's cell and its structure under the microscope. In 1938 he contributed to the cell theory and stated that every tissue present in the plant is made of or cells and an embryonic plant is produced from one single cell.
In 1939 another scientist Theodor Schwann proposed the same conclusion after studying animal cells and concluded that the basic unit of life is cell and every organism on earth is made up of one or more cells. Therefore Theodor Schwann and Matthias Schleiden have great contribution in cell theory.
Answer:
Option a) higher the average sea levels.
Explanation: Carbondioxide is also known as greenhouse gas. When carbondioxide concentration is higher in the atmosphere, it prevents the reflected sunlight from going into the atmosphere which increases the temperature of the surrounding air. This phenomenon is called global warming. This increase in temperature starts melting of ice which are present on mountains and thus, increases sea level.