• Meristematic tissue has cells small in size and isodiametric in shape. Permanent tissue has cells large in size and their shape varies.
• Vacuoles are usually absent in meristematic tissue. Vacuoles are present in living cells of permanent tissue.
Choice B:
More photosynthesis leads to more oxygen in the atmosphere and oceans.
Answer:
The correct answer is A. Tobacco mosaic virus
Explanation:
Virus can have DNA and RNA as its genetic material. Tobacco mosaic virus has RNA as its genetic material. Protein is not a genetic material because it is a product coded by genetic material.
So a hybrid can be made only when the genetic material of two different organisms is mixed not two different biomolecules. Therefore when RNA from the tobacco mosaic virus is mixed with the protein from a DNA virus the result would be a tobacco mosaic virus only.
Answer:
The correct answer is A. The cartilaginous structure between the "throat" and the trachea is the larynx.
Explanation:
The larynx is a tubular organ. The larynx wall is composed of 9 pieces of cartilage. Three are odd (thyroid cartilage, epiglottis and cricoid cartilage), and three pairs (arytenoid, cuneiform and corniculate cartilage). In addition, it communicates the pharynx with the trachea and is in front of it.
Darwin’s Finches: Darwin observed that beak shape varies among finch species. He postulated that the beak of an ancestral species had adapted over time to equip the finches to acquire different food sources. This illustration shows the beak shapes for four species of ground finch: 1. Geospiza magnirostris (the large ground finch), 2. G. fortis (the medium ground finch), 3. G. parvula (the small tree finch), and 4. Certhidea olivacea (the green-warbler finch) the Grants measured beak sizes in the much-reduced population, they found that the average bill size was larger. This was clear evidence for natural selection of bill size caused by the availability of seeds. The Grants had studied the inheritance of bill sizes and knew that the surviving large-billed birds would tend to produce offspring with larger bills, so the selection would lead to evolution of bill size. Subsequent studies by the Grants have demonstrated selection on and evolution of bill size in this species in response to other changing conditions on the island. The evolution has occurred both to larger bills, as in this case, and to smaller bills when large seeds became rare.
