in protostomes the blastopore develops into the

Depending on the animal species, the process can occur within the body of the female in internal fertilization, or outside in the case of external fertilization. In animals, the process involves a sperm fusing with an ovum, which eventually leads to the development of an embryo. įertilization is the fusion of gametes to produce a new organism. Different taxa show different cellular and acellular envelopes englobing the vitelline membrane. The first envelope – the one in contact with the membrane of the egg – is made of glycoproteins and is known as the vitelline membrane (zona pellucida in mammals). It is covered with protective envelopes, with different layers. Unlike other animals, sponges _.The egg cell is generally asymmetric, having an animal pole (future ectoderm). Which of the following is characteristic of protostomes? ()Ĭell fate is determined early during embryonic development. Which of the following is a trait shared by protostomes and deuterostomes? ()

()Īn animal with a true coelom that has _ cleavage must be a(n) _. The zygotes of many protostomes undergo _ cleavage and _ cleavage. Retain the capacity to develop into a complete embryo ()įorm ectoderm but not endoderm or mesodermįorm mesoderm but not endoderm or ectodermĭo not divide according to any recognizable pattern Indeterminate cleavage produces embryonic cells that _. It permits the development of an open circulatory system It is a requirement for a complete digestive tract It allows for a third embryonic germ layer It allows room for the development and movement of internal organs The presence of a coelom is advantageous because _. Lined on one side by mesoderm and on the other side by endoderm A pseudocoelomate animal is one in which the body cavity is _. One of the primary developmental/anatomical characteristics distinguishing the major animal phyla is the condition of the body cavity. ()Ī body cavity lined with endoderm and mesodermĪ body cavity lined with tissues derived from the endoderm the lining of the digestive tubeĪll animals with bilateral symmetry have _ germ layer(s). In the embryo of a shark, ectoderm gives rise to _ mesoderm gives rise to _ endoderm gives rise to _. Which of the following is a characteristic of cnidarians? () Which of the following features is associated with bilateral symmetry? () Which of the following groups does NOT exhibit bilateral symmetry? () Large mammalian herbivores and carnivores arose.Ī great diversity of new body plans emerged among animals.įishes emerged as top predators in marine food webs. Which of the following occurred during the Mesozoic era? () Increased numbers of predator species led to a dramatic decline in prey species.Īn increase in atmospheric CO 2 led to an explosion of plants and life-forms that fed on plants.Įvolution of the Hox gene complex provided developmental flexibility. Which example below is a current hypothesis regarding the Cambrian explosion? ()Ī rise in atmospheric nitrogen led to success of large animals with higher metabolic rates. Which of the following correctly lists the embryonic stages in the order that they develop? ()

These young animals undergo _ to become _, which resemble adults but are not yet sexually mature. Many young animals are _, a sexually immature form that is morphologically distinct from the adult stage. How do animals differ from these protist ancestors? ()Īnimals have more cells than their protist ancestors, and their cells show greater specialization.ĭuring the development of most animals, cleavage leads to _. Their cells are supported and connected to one another by structural proteins.Īnimals probably evolved from colonial protists. They release enzymes to the outside of the body to aid in digestion. Which characteristic below is shared by plants, fungi, and animals? ()

In protostomes the blastopore develops into the