Answer:
<em>The shape of a cell can easily be seen through a light microscope.</em>
Explanation:
A microscope can be defined as a device which is used to visualize things which are otherwise not visible to the naked eye. The shape of a cell can be seen even through a light microscope. For example, an animal cell can be seen to have a round shape under the light microscope, a plant cell will be seen rectangular under the light microscope.
Other microscopes such as the electron microscope can even show the organelles present inside the cell.
Parasite: Parasites are different from predators because parasites only take resources from one host, whereas predators eat many prey. A good example of this is the trematode parasite Schistosoma mansoni. An adult schistosome parasite lives inside of just one human host
Answer:
Electrons become excited.
Explanation:
Electrons in the chlorophyll get excited and pass on the energy to other electrons.
<h2>The given statement is true</h2>
Explanation:
Iron absorption occurs in the duodenum and upper jejunum of small intestine
- At physiological pH ferrous iron is rapidly oxidized to the insoluble ferric form
- Gastric acid lowers the pH in the duodenum which enhances the solubility and uptake of ferric iron
- Once iron gets inside the enterocyte it can be stored as ferritin;Ferritin is a hollow spherical protein which helps in storage and regulation of iron levels within the body
- Ferritin molecule have ferroxidase activity which helps in the mobility of Fe2+ out of the enterocyte by ferroportin
- Transferrin is the major iron transport protein which transports iron through blood
- Fe3+ binds to transferrin so Fe2+ transported through ferroportin must be oxidized to Fe3+
- Fe2+ needs to be oxidized first so that it can be transported through ferroportin
- Once iron gets inside the cell it can be used for various cellular processes
Answer:
D. Selection has led to decreases in the size of fish at the age of reproductive maturity.
Explanation:
The larger body size of the fishes is not an adaptive trait as it reduces the survival chances of these fishes. The process of natural selection tends to increase the frequency of the traits that increase the survival fitness of the organisms. Here, the fishes with smaller body size at the reproductive age have greater chances of survival and would reproduce more to leave more progeny. Over the generations, the selection pressure would increase the proportion of fishes that are smaller during reproductive age.
