Question

Homework 3

11.An animal that possesses an ectoderm, mesoderm and endoderm is called _________________.

13.Which statement below best describes Pattern Formation during embryonic development?

a. An intermediate step in the process of embryogenesis is the formation of three body axes.

b. Gradients of gene products such as bicoid and nanos, placed into the egg by nurse cells, define the anterior-posterior axis of the Drosophila embryo.

c. Bicoid mutants develop without a posterior end and nanos mutants develop without a head end.

d. Egg cytoplasm must be homogeneous in gene products to support normal Drosophila embryogenesis.

1. Which of the statements found below is accurate? (More than one answer)

a. Scientists believe that radial and spiral cleavage patterns have evolved many times during the evolution of animals.

b. In radial cleavage, mitotic division produces tiers of cells, or layers, on top of one another.

c. Spiral cleavage is associated with regulative develepment.

d. In spiral cleavage, mitotic division produces cells that lie in furrows between slightly older cells.

Homework 4

1. If a taxon includes the most recent common ancestor of a group of organisms and all of the descendants of that ancestor, it is termed ______.
2. If two different taxa share common ancestry with each other more recently than either one does with any other organisms, we call them _______ ______.

Homework 5

1. How does the mosquito transmit malaria from an ill person to a healthy person?

a. Plasmodium is taken up from one person's blood and squirted back out into the next person.

b. Plasmodium gametocytes are taken up from one person's blood and cross into the saliva duct to be reinjected into the next person.

c. Plasmodium gametocytes are taken up from one person's blood, fuse to form a zygote that becomes a motile ookinete that enters the saliva ducts.

d. Plasmodium gametocytes are taken up from one person's blood, fuse to form a zygote that becomes a motile ookinete, that crosses the stomach wall, forms an oocyst that undergoes sporogony and the sporozoites then migrate to the saliva ducts to be injected into the human host.

e. Plasmodium gametocytes are sucked from one person's blood, form an oocyst that undergoes sporogony and the sporozoites migrate across the stomach lining to the saliva ducts.

1. The kingdom Protozoa is made up of numerous types of single-celled organisms. Because they are all unicellular the protozoans are a monophyletic group.

True

False

Answer 1

11. Triploblastic, as it have three germ layers

13. option B is correct, bicoid is a maternal effect gene their protein concentration ghradient patterns the anterior posterior axis during drosophila embryonic development

14. option B is correct, In radial cleavage, mitotic division produces tiers of cells, or layers, on top of one another. in radial cleavage cell division has occured so that the cells are aligned directly over eachother, but in spiral cleavage cells are not aligned directly but rather are aligned at an angle.

15. monophyletic taxon which includes most recent common ancestor of a group of organism and its all descendants such groups sometimes called holophyletic.

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