Veins carry blood to the heart while arteries carry blood away from the heart distributing it throughout the body.
Answer:
D.Each chromosome consists of a single long DNA molecule, and each gene on the chromosome is a particular segment of that DNA.
Explanation:
A closed DNA molecule contains two strands of linear nucleotide sequences, and both DNA strands contain genes. These genes are DNA sequences that may be transcribed in messenger RNAs (mRNAs).
The cell nucleus contains chromosomes in which the double-stranded DNA molecules are packaged by specialized proteins (histones). Moreover, there are organelles (mitochondria and chloroplast) that also contain genes which are transcribed in an analog mode to genes contained in the nuclear chromosomes.
The first cell that was viewed by the light microscope was the oak bark.
Answer:
The population size of bacteria reaches to 6,40,000 in two hours.
Explanation:
At the beginning, the population size of bacteria is 10000. After each 20 minutes, the population of bacteria is double. So after 20 minutes, the population of bacteria is 20000 due to splitting in two equal parts. After 40 minutes, the population reaches to 40000. By completing one hour, the population size will be 80000. After 80 minutes, the population reaches to 160000. By completing 100 minutes, the population size will be 320000. For two hours, this 320000 will be double and the population reaches to 640000.