I'd say, ina general way, that the most imporant cells in defense against parasitic organisms are definitely white blood cels, the cells responsible for defeating antigens, pathogens and deseases.
Although these might be the most important ones in that specific task (defending against parasitic organisms), all the cells in the immune system, along with other non-cell things are important, since they all play a specific role indispensable in our immune system.
Hope it helped,
BioTeacher101
Answer:
The xylem consists of tracheary elements, xylem parenchyma cells, and xylem fiber cells.
Answer:
This definition suits that of "HOMOLOGOUS CHROMOSOMES"
Explanation:
Homologous chromosomes are similar pairs of chromosomes i.e. in length, gene positioning and centromere location (one from each parent) but not identical. Homologous chromosomes are not identical in the sense that, alleles on each pair may be different, resulting in genetic variation of the offspring.
Using humans as a case study, a karyotype (pictorial display of chromosomal arrangement) shows the complete set of chromosomes, which has two complete set (diploid). Each human cell contain 23 pairs of chromosomes, with each pair contributed by each parent i.e. 46 chromosomes in total. Every chromosome pair represents a set of homologous chromosome.
Genetic variation is the variation in the DNA sequence in the genome of an organisms. Organisms of a species have similar characteristics but they are not identical due to genetic variation. Genetic variation is important in the survival and the adaptability of a given species of organism. Therefore, in this case lack of genetic variation necessary to adapt to change in the environment will lead to extinction of the fish species that lacks the variation.
