Concept explainers
Videos
To review:
The mechanism of avian feather formation. Also explain the factor that patterns the placement of the feather bud placodes.
Introduction:
In avian species, feather formation begins from the feather follicles. Feather follicles are the invaginations starts in the epidermis down to the dermis. Dermis is the region where the follicle and pulp cavity starts to form the feather. Cell proliferation leads to the growth of feather filament, out of the follicle. Two different tissues are formed from the new cells, one is the sheath that surrounds the feather and second is pulp cap which protect the dermal core. Along the cell growth, spa the develops continuous and followed by the formation of calamus which is the quill of the feather.
Explanation of Solution
Epidermal placode is the first morphological manifestation of the embryonic feather of avian, which is a circular cluster of columnar ectodermal cells. After the placode formation, a dermal condensation is takes place beneath the epidermal placode. The outgrowth of the epidermal placode leads to the formation of feather bud and filament. This process is accompanied by the resumption of epidermal and dermal cell proliferation. Specific morphogenetic and proliferative events organize the discrete populations of epidermal cells and lead patterns in feather tracts. Periodic patterning within the tracts leads the division of originally homogeneous field into feather bud and interbud regions. This patterning is regulated by the expression pattern of several genes. Wnt-7a, β-catenin, L-Fringe, and NCAM are few genes which show the restrictive expression those progresses to the bud domain. The arrangement of the feather is shows a repeated hexagonal pattern on the avian body surface. Feather periodic patterning is regulated by a number of molecules that promote (activators) and suppress (inhibitors) feather bud formation. Fibroblast growth factors, such as FGF2 acts as activators and BMPs are known as inhibitors.
Thus it is concluded that formation begins from the feather follicles. Feather follicles are the invaginations starts in the epidermis down to the dermis. Periodic patterning within the tracts leads the division of originally homogeneous field into feather bud and interbud regions. This patterning is regulated by the expression pattern of several genes.
Want to see more full solutions like this?
Chapter 16 Solutions
Developmental Biology
- Describe and give a specific example of how successionary stage is related to species diversity?arrow_forwardExplain down bellow what happens to the cell in pictures not in words: Decreased pH in mitochondria Increased ATP Decreased pH in cytosol Increased hydrolysis Decreasing glycogen and triglycerides Increased MAP kinase activity Poor ion transport → For each one:→ What normally happens?→ What is wrong now?→ How does it mess up the cell?arrow_forward1.) Community Diversity: The brown and orange line represent two different plant communities. a. Which color represents the community with a higher species richness? b. Which color represents the community with a higher species evenness? Relative abundance 0.1 0.04 0.001 2 4 6 8 10 12 14 16 18 20 22 24 Rank abundance c. What is the maximum value of the Simpson's diversity index (remember, Simpson's index is D = p², Simpson's diversity index is 1-D)? d. If the Simpson's diversity index equals 1, what does that mean about the number of species and their relative abundance within community being assessed?arrow_forward
- 1.) Community Diversity: The brown and orange line represent two different plant communities. a. Which color represents the community with a higher species richness? b. Which color represents the community with a higher species evenness? Relative abundance 0.1 0.04 0.001 2 4 6 8 10 12 14 16 18 20 22 24 Rank abundance c. What is the maximum value of the Simpson's diversity index (remember, Simpson's index is D = p², Simpson's diversity index is 1-D)? d. If the Simpson's diversity index equals 1, what does that mean about the number of species and their relative abundance within community being assessed?arrow_forwardwhat measures can a mother to take to improve the produce of her to milk to her newborn baby ?arrow_forward1. Color the line that represents all ancestors of the Eastern white pine tree green (but only the ancestral line NOT shared with other organisms) 2. Oncle the last common ancestor of the Colorado blue spruce tree and Eastern white pine tree. 3. Put a box around the last common ancestor of the sugar maple tree and the dogwood tree. 4. Put a triangle around the last common ancestor of the red pine tree and the american holly bush. 5. Color the line that represents all ancestors of the Ponderosa pine tree red (including all shared ancestors). 6. Color the line that represents all ancestors of the American elm tree blue (including all shared ancestors). 7 Color the line that represents all ancestors of the Sabal palm tree purple (including all shared ancestors) 8. Using a yellow highlighter or colored pencil, circle the clade that includes all pine trees. 9. Using a orange highlighter or colored pencil, circle the clade that includes all gymnosperms 10. Can you tell…arrow_forward
- You have been hired as a public relations specialist to give invertebrates a good name. After all, they are much more than just creepy crawly bugs! Your first task though is to convince yourself that is true. The best way to do that is to start close to home. Find something in your house that is a product obtained directly from an invertebrate or only due to an invertebrate’s actions. Describe the product, its function and utility, as well as any human manufactured alternatives. Be sure to highlight the advantages of obtaining this directly from nature. Keep in mind, a product can be something you use, wear, eat, or enjoy for its visual appeal.arrow_forwardUse the following tree diagram to answer Questions #8-10. 8) Which of the following two animals are the most closely related based on the tree to the left? a) Pig and camel b) Hippo and pig c) Deer and cow 9) CIRCLE on the tree diagram where the common ancestor between a hippo and a cow is. 10) Put a SQUARE on the tree diagram where the common ancestor between a pig and a peccary is.arrow_forwardExplain: Healthy Cell Function Overview→ Briefly describe how a healthy cell usually works: metabolism (ATP production), pH balance, glycogen storage, ion transport, enzymes, etc. Gene Mutation and Genetics Part→ Focus on the autosomal recessive mutation and explain: How gene mutation affects the cell. How autosomal inheritance works. Compare the normal and mutated gene sequences simply. → Talk about possible consequences of a faulty hydrolytic enzyme.arrow_forward
- Can you fill out those termsarrow_forwardExplain down bellow what happens to the cell: Decreased pH in mitochondria Increased ATP Decreased pH in cytosol Increased hydrolysis Decreasing glycogen and triglycerides Increased MAP kinase activity Poor ion transport → For each one:→ What normally happens?→ What is wrong now?→ How does it mess up the cell?arrow_forwardAn 1100 pound equine patient was given 20 mg/kg sucralfate 3 times a day, 2.8 mg/kg famotidine twice a day, and 10mg/kg doxycycline twice a day. Sucralfate comes as a 1 gm tablet, famotidine as 20 mg tablets, and doxycycline as 100mg tablets. All are in bottles of 100 tablets.How many total mg are needed for the patient and how many tablets of each would be needed to provide each dose?How many bottles of each would be needed to have available if this patient were to be on this drug regimen for 5 days?arrow_forward
Anatomy & PhysiologyBiologyISBN:9781938168130Author:Kelly A. Young, James A. Wise, Peter DeSaix, Dean H. Kruse, Brandon Poe, Eddie Johnson, Jody E. Johnson, Oksana Korol, J. Gordon Betts, Mark WomblePublisher:OpenStax College
Understanding Nutrition (MindTap Course List)Health & NutritionISBN:9781337392693Author:Eleanor Noss Whitney, Sharon Rady RolfesPublisher:Cengage Learning
Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning
Case Studies In Health Information ManagementBiologyISBN:9781337676908Author:SCHNERINGPublisher:CengageHealth Safety And Nutrition F/Young ChildHealth & NutritionISBN:9781305144767Author:MAROTZPublisher:Cengage
Biology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStax