![petroale000](/avatars/43991.jpg)
petroale000
03.08.2019 •
Biology
State the role in the menstrual cycle of the following hormones, fsh, lh, estrogen and progesterone
Solved
Show answers
More tips
- H Health and Medicine What to Eat to Lose Weight?...
- S Society and Politics Will Japan become Russia s Military Enemy?...
- P Philosophy Is Everything We Strive for Eventually Achieved and Destroyed?...
- S Society and Politics Understanding Politics and Its Role in the Development of Civilization...
- P Philosophy Why Did God Create Man and Place Him in Obscurity?...
- S Society and Politics Skoptsy: Who They Are and How They Perform Castration?...
- O Other Childhood Fears: What Many of Us Experienced...
- P Philosophy What is Something for you?...
- H Health and Medicine Why Do Humans Have One Heart?...
- P Philosophy Unbelievable stories of encounters with otherworldly forces...
Answers on questions: Biology
- B Biology Which characteristics is shared by both prokaryotes and eukaryotes A. need oxygen gas to breathe B.maintain homeostatis c.make their own food D.have organ system please make sure it...
- B Biology Reactions between atoms occur when: A :an atom seeks to fill its outer shell of electrons B :an atom seeks to balance its positive and negative charges C :the reaction will result...
- B Biology Which digestive enzymes are secreted in the mouth? insulin protease pepsin alpha-amylase none of the above answer choices is correct?...
- B Biology An inference a. is a possible explanation for events using prior knowledge b. explains if a hypothesis is or is not valid c. is made independent of observation or prior knowledge d....
- B Biology Briefly explain what happens in each of the two stages of photosynthesis....
- B Biology Which of the following is an adaptation to life on land used by both plants and animals? a. development of fertilization systems that required the organism to return to water. b. modifying...
- B Biology Which of the following statements regarding the chemical mediators of inflammatory responses is not true? a. they may be secreted by cells residing in the area of injury. b. they may...
- B Biology Is a species more or less likely to go extinct if it has a lot of genetic variation?...
- B Biology What links the two strands in a dna helix together in the middle ?...
- B Biology Ants carry dead ants out of an anthill and dump them on a trash pile. to study this behavior, a scientist paints a live ant with a chemical from dead ants. the scientist observes that...
Ответ:
Ответ:
starfish are also referred to as sea stars because of their star-shaped appearance. They are a part of the phylum Echinodermata and are related to sand dollars, sea urchins, and sea cucumbers. Echinoderms are found in nearly all marine habitats and constitute a major proportion of the biomass. Starfish belong to the class Asteroidea, derived from the Greek words “aster” (a star) and “eidos“ (form, likeness, appearance). There are more than 1600 species of starfish alive today, and they have an important role in the community structure of the ocean floor.
Feeding: Starfish are mostly predators and feed on invertebrates such as mussels and clams that live on the ocean floor. Several species have specialized feeding behaviors including eversion of their stomachs. This means the starfish extends its stomach out of its mouth and over the digestible parts of its prey. The prey tissue is partially digested outside of the body, then the starfish brings its stomach back inside into its 10 digestive glands to finish feeding. If you want to learn more about this process, check out this article in the Journal of Experimental Biology where researchers investigated the compound that plays a role in this feeding behavior.
Movement: On their ventral side, starfish contain thousands of tube-like feet that contain cells that are specialized for adhesion. In a process that Dr. Pawson describes as ”rapid gluing and ungluing,” starfish can use these tube feet to move across a surface. Each foot has two sets of secretory cells that secrete compounds that allow the foot to first attach then detach to a surface. The first set of cells releases an adhesive material that bonds the fuzzy coat (the outermost layer of the tube foot) to the surface (ocean floor). A different substance is released from a second type of secretory cells that enables the foot to release from the ocean floor or other surfaces.
Regeneration: Can you imagine having the ability to regrow a part of your body? Most species of starfish can regenerate, or regrow, damaged or lost arms. They can also shed arms as a means of defense. If an arm is damaged by a predator such as another starfish or a crab, the starfish can detach that arm and grow a new, healthy one. Or if a predator grabs onto the starfish by one of its arm it can detach that arm as a means to escape from the predator. Regeneration is one way starfish have remained abundant in the diverse marine world.
Starfish and other echinoderms are extremely important to the biodiversity of our oceans. I hope that the next time you see a starfish while visiting the beach, you can take a moment to reflect in both their beauty and their importance to life on this planet.
(https://ssec.si.edu/stemvisions-blog/all-about-starfish)