Answer:
Nitrogen fixation is a process by which nitrogen (N2) in the atmosphere is converted into ammonia (NH3). Atmospheric nitrogen or elemental nitrogen (N2) is relatively inert: it does not easily react with other chemicals to form new compounds. Dinitrogen is quite inert because of the strength of its N≡N triple bond.
Answer:
Organisms better adapted to the environment
Explanation:
According to the evolutionary theory proposed by Charles Darwin in "The Origin of Species" (1859), the fittest organisms are those that are better suited to the environment (i.e., have a higher fitness). These organisms have more chances to survive and reproduce, and thereby they have also more chances to leave their genes in the next generation. This process is the central concept of evolution, and it is called natural selection. In consequence, evolution produces phenotypic changes or 'adaptations' that are inherited by organisms over generations, and certain traits are lost during this process.
Answer:
4/16 (i.e. 25%)
Explanation:
A dihybrid cross is a cross between two organisms/lines/genes that are hybrids (i.e., heterozygous) for two different traits. In a standard dihybrid cross, there is a relation of complete dominance for both <em>loci</em>, i.e., there are two alleles that are completely dominant and thus mask the effects of the corresponding recessive traits. In a dihybrid cross involving two different genes that assort independently into gametes during meiosis, with dominant alleles "A" and "B" and recessive alleles "a" and "b", respectively, the expected phenotypic ratio will be 9:3:3:1 (ie. 9/16 A_B_, 3/16 A_bb, 3/16 aaB_ and 1/16 aabb), while the expected genotypic ratio of double heterozygous "AaBb" individuals will be 4/16, i.e. 25%.
Representation:
P generation >> AaBb (father) X AaBb (mother)
Gametes (for both parents) >> 1/4 AB; 1/4 Ab; 1/4 aB; 1/4 ab
F1 generation >> 1/16 AABB; 2/16 AABb; 2/16 AaBB; 4/16 AaBb; 1/16 AAbb; 2/16 Aabb; 1/16 aaBB; 2/16 aaBb; 1/16 aabb
Answer:
Bacteria are much larger than viruses, and they are too large to be taken up by receptor-mediated endocytosis. Instead, they enter host cells through phagocytosis. Phagocytosis of bacteria is a normal function of macrophages.
