Theory questions answers essay example

Theory questions and answers

Answer to the theory questions.
The phylum without organs includes the phylum porifera and the body symmetry is irregular.
The phylum without cephalization is that of phylum porifera and phylum echinodermata
Not all the organisms on the table have three germs layers. Those without 3 germ layers are phylum cnidarians and phylum porifera
Phylum arthropoda has more species compared to other phyla and few examples include; various subphylum’s such as trilobitomorpha, chelicerata, myriapoda, crustacea, hexapoda. Subphyla chelicerata include those; arachnida, xiphosura, pycnogonida and eurypteridia.
In terms of differences in fishes anatomical structure fishes could be classified as jawless fishes, cartilaginous fishes, and bony fishes. The jawless category are the primitive forms of fish. Their class is termed Agnatha and they are without jaws. They also lack paired pelvic structures and pectoral fins. The two major types of fish in this category are the lampreys and hagfishes.
The cartilaginous fishes are those groups, which are more advanced than the jawless group in terms of anatomic structures. They have a skeleton made up of cartilage and then lack swim bladder or tail fins. The major members of the group are the sharks and rays. Denticles, which look like tooth is the main structure that cover the skin of the fishes in this group.
The bony fishes are the third group and the most common. Their skeleton is bony and they possess swim bladder. They are subdivided into fleshy finned type or ray-finned type. The ray type is the most common and it include about 95percent of all living fishes while the remaining type which are the ray-finned are predominantly fresh and marine environment.
The three major groups of mammals are monotremes, marsupials, and placental mammals. Monotremes are the types of mammal that do lay eggs. They are not common and the few that are found on earth now are the spiny anteater or platypus. The marsupials are don’t lay eggs but their own ways of life is to cather for their younger ones in a form of pouches. This is because they give birth to the younger ones at a very immature state hence needed to keep those babies inside their pouch for protection and further development. They include kangaroo and numbat. The placental mammals are the largest group of mammals. They give birth to the younger ones in a more advanced stage and before they those younger ones are born, the mother nourish them via placental. This group includes the cats, dogs, and humans.

The Discussion answers; Angiosperm modification

Carrion plant flower also known as Stapelia gigantea is an angiosperm with a structural modification that is related to pollination. This angiosperm is a flowering plant that produce large amount of flowering odor, which appears like a rotten meat, and this odor tends to attract flower pollinators to the plants to facilitate pollination. This modification help the plant survive in its environment.
The flowers producing the smell usually shoots from the younger part/base and their shape that of flat and starfish. They come out mostly with orange, dark red or brown colors. There will also be some form of purplish hairs at the middle or central part of the flower. The structural modification of the plant also provides room for the eggs of the pollinating insects.

References

Cactus art nursery, 2011. Stapelia grandiflora. Cultivation and mail sale of cacti and succulents.

Retrieved 1 November, 2011 from http://www. cactus-art. biz/schede/STAPELIA/Stapelia_grandiflora/Stapelia_grandiflora/stapelia_grandiflora. htm
Carter, J. (2004). Angiosperm.

Retrieved 1 November, 2011 from http://biology. clc. uc. edu/courses/bio106/angio. htm