Water travels upwards through xylem, a type of plant vascular tissue. Vascular Tissue. Transport ... Both xylem and phloem are made of elongated cells placed end-to-end like sections of a pipe.
An aromatic group is a functional group which gives a positive test in a xanthoproteic test.
Xanthoproteic is a test for protein detention. The concentrated nitric acid reacts with proteins if they are present to form yellow colour. By adding alkali it turns orange-yellow through xanthoproteic reaction. Due to a phenyl group, the hydroxyl group can make the test positive in xanthoproteic.
An aromatic group consists of six hydrocarbons with an alternating single and double bond between carbon atoms which form rings.
Answer:
Crossing over is the phenomenon by which homologous chromosomes exchange DNA segments between them during the process of meiosis.
If crossing over did not occur, there will be no genetic variation among parents and offsprings.
If the process of meiosis did not occur, there will be lesser chances of genetic variations to occur. Each chromosome will be either from the father or the mother with no genetic diversity present in it. As a result, genetic diversity will reduce.
The KT boundary marks a mass extinction event. the KT boundary is the time between the Cretaceous and Tertiary periods. An asteroid hit the earth at the end of the Cretaceous and that caused the end of the Cretaceous period. Before the KT boundary, pollen from angiosperms and gymnosperms is high. After the meteor hits the earth, a mass extinction occurs and the amount of pollen from gymnosperms and angiosperms decreases dramatically, while the amount of spores from ferns increases. During the Cretaceous period there were many species of gymnosperms and angiosperms but they disappeared at the KT boundary, when the asteroid hit the earth.
