Megasporogenesis

What is the number of nuclear division in megaspore mother cell for the formation of a female gametophyte ?

Define and identify the relationship that the following have with stress

I started to answer these could you please help me ? C. Define and identify the relationship that the following have with stress: Epinephrine: A hormone secreted by the adrenal medulla. Epinephrine plays a central role in the short-term response to stress reaction. It is the physiological response to threatening excitement or environmental stressor such as high noise. ACTH-glucocorticoids: A hormone secreted by the Adrenal Cortex. During stress ACTH-glucocorticoids increase blood glucose level. ADH-vasopressin: An anti-diuretic hormone secreted by the pituitary gland. Headache, decreased energy, low libido, and weight gain may be attributed to TSH-thyroxin insulin/gluca... click for more

Several questions

G. Draw and label an in vitro cellular aging curve-Phase I, II, and III. H. What are the typical conditions for growing human cells outside the body? Compare use of serum vs. defined medium. I. Define a population doubling-in vitro. How many can you expect from a human, chicken, and mouse? J. Explain pulse-labeled-nuclei, tritiated thymidine, and autoradiography. K. Compare cell lines vs. cell strains. L. What is transformation and how does this compare to in vitro aging? What is oncogenesis, onco virus, and onco gene? M. What are the advantages/disadvantages to in vitro cell culturing as related to aging? N. Describe aging and relate it to functions in mem... click for more

Help determining Taxonomic classifications based on differences and similarities of their traits.

Animals are placed in taxonomic classifications based on differences and similarities of their traits. If you know what critical traits to look for, it is possible to separate any animal into a taxonomic category. Download the document U5IP Table. The document contains a table with images. The images are examples of each Phylum: Porifera, Cnidaria, Platyhelminthes, Annelida, Mollusca, Arthropoda, Nematoda, Echinodermata, and Chordata. First, use the table in your textbook (page 428) to determine which Phylum each organism falls into (you will find a description of chordata on page 450). List the specific traits that distinguish each Phylum . (Please do not just copy the list from t... click for more

Taxonomy

I am studying Amniota and I was wondering if someone could explain to me the following concepts. I know that the features of Chordata are the notochord, dorsal nerve cords, gill clefts (except for Tunicata); segmented muscles and a post-anal tail. I know that developmentally we are related to echinoderms. Can you explain the relationship between the Cordata and Echinodermata? Using the bird, reptile and mammal (or those that came from an aminotic egg) as an example can you explain the following: a) Why these 3 (bird, reptile and mammal) are grouped together? b) What advantages (from an evolution perspective) do these three (as representatives of chordata) have over echinoderms? c) H... click for more