Segmentation in the annelid worms has facilitated locomotion and specialization of different parts of these animals. Evaluate the following statements about segmentation in the annelids and determine if they are true or false.
a. Excretion is accomplished by paired protonephridia with flame cells in every segment of the body ci k to select
b. If the organs in one segment fail, the organs of another segment will still function
c. Annelids possess both circular and longitudinal muscles that produce waves of contraction that are propagated down through the points eBookseries of segments.
d. Segmentation has allowed for specialization in the anterior of the annelid body, which has provided for a more sophisticated nervous system

a. Excretion is accomplished by paired protonephridia with flame cells in every segment of the body. True

Most anelids have structures called metanephrids or protonephridia. Both structures are homologous to the kidneys and have the function of excresion, A pair are present in every segment of the body.

b. If the organs in one segment fail, the organs of another segment will still function. False

It is false because all segments are interrelated and have different functions depending on their location.For example, the first segment is where the sensory appendages are, such as the antennae and the eyes. The second segment is where the mouth is. There are a series of parapod segments to move, collectively called metameres and ends in a terminal portion called pigidium, where the anus is located.

c. Annelids possess both circular and longitudinal muscles that produce waves of contraction that are propagated down through the points eBookseries of segments.True

True because anelids have circular and longitudinal muscles that serve to function the hydrostatic skeleton.

d. Segmentation has allowed for specialization in the anterior of the annelid body, which has provided for a more sophisticated nervous system. True

True because the segmentation allows to have a nervous system formed by a ventral nerve cord provided with ganglia and lateral nerves in each segment.

fertilization, pictured in figure 24.23a is the process in which gametes (an egg and sperm) fuse to form a zygote. the egg and sperm each contain one set of chromosomes. to ensure that the offspring has only one complete diploid set of chromosomes, only one sperm must fuse with one egg. in mammals, the egg is protected by a layer of extracellular matrix consisting mainly of glycoproteins called the zona pellucida. when a sperm binds to the zona pellucida, a series of biochemical events, called the acrosomal reactions, take place. in placental mammals, the acrosome contains digestive enzymes that initiate the degradation of the glycoprotein matrix protecting the egg and allowing the sperm plasma membrane to fuse with the egg plasma membrane, as illustrated in figure 24.23b. the fusion of these two membranes creates an opening through which the sperm nucleus is transferred into the ovum. the nuclear membranes of the egg and sperm break down and the two haploid genomes condense to form a diploid genome.

explanation: