Chromosomes exchange genetic material in step 3.
<h3><u>Explanation</u>:</h3>
The meiosis is the type of cell division that takes place for gametogenesis. The meiosis has two phases - meiosis I and meiosis II.
The meiosis I has the events like crossing over and independent assortment which leads to the mixing of genes between homologous chromosome pairs and separation of homologous chromosome pairs. So the two cells that are produced from the meiosis I are genetically different. The step 3 shows the crossing over of prophase 1 of meiosis I. So, it shows the genetic difference between the offsprings and leads to genetic variation.
The end result is production of four haploid cells (n chromosomes, 23 in humans) from the two<span> haploid cells (with n chromosomes, each consisting of </span>two<span> sister chromatids) produced in </span>meiosis<span> I. The four main </span>steps of Meiosis II<span> are: Prophase </span>II<span>, Metaphase </span>II<span>, Anaphase </span>II<span>, and Telophase </span>II<span>.</span>
<h2>Transportation across the membrane</h2>
Explanation:
(a) Simple diffusion; Faciliated diffusion-Directions in which two transported solutes move
- In simple diffusion diffusion of non polar compounds across the membrane and along the concentration gradient without the involvement of protein whereas in case of facilitated diffusion membrane transport proteins that facilitate movement pf molecules across the membrane down its concentration gradient
- Both the diffusions does not require energy
(b) Facilitated diffusion; active transport-Direction the solute moves relative to its concentration gradient
- In facilitated diffusion membrane transport proteins that facilitate movement of molecules across the membrane down its concentration gradient without the expenditure of energy
- Active transport drives transportation of solute against the concentration gradient across the membrane
(c) Simple diffusion; Active transport-Directions in which two transported solutes move and Direction the solute moves relative to its concentration gradient
- In simple diffusion diffusion of non polar compouds across the membrane and along the concentration gradient without the involvement of protein and energy
- Active transport drives transportation of solute against the concentration gradient across the membrane;secondary active transporters coupled with transportation of two solute molecules
(d) Direct active transport; Indirect active transport-Direction the solute moves relative to its concentration gradient or its electrochemical potential
- Direct active transport use direct energy such as ATP hydrolysis,oxidation and sunlight energy
- Indirect active transport use indirect energy such as chemical gradient,electrochemical gradient established by direct active transporters;one solute moves along the concentration gradient while other moves against the concentration gradient
(e) Symport; Antiport-Direction in which two transported solutes move
- In symport both the solute molecules move in same direction;coupled with primary active transport(direct transport)
- In antiport both the solutes moves in opposite direction;coupled with secondary active transport(indirect transport)
(f) Uniport; coupled transport-Directions in which two transported solutes move
- Uniport is the transport of single solute across the membrane
- Coupled transport is the transport of two solute molecules across the membrane;it may be symport or antiport
(g) P-type ATPase; V-type ATPase-Kinetics of solute transport
- P-type ATPase always transport cations and undergoes phosphorylation
- V-type ATPase(here V stands for vacuole) transport protons and no phosphorylation occurs;catalytic activity is not reversible
- Both are types of primary active transporters
Answer:
Answer is option A.
Vestigial features are fully developed and functional in one group of organisms but reduced and function less in a similar group.
Explanation:
- Vestigial structures are anatomical features such as cells, tissues or organs in an organism that are previously functional and performed some important functions in the organism but no longer serve any functions in the current form of the organism and become useless as a result of a large evolutionary change. Examples include the coccyx or the tailbone in humans, the pelvic bone of a snake, wisdom teeth in humans, nipples in human males, the wings of flightless birds such as kiwi, ostrich, etc.
- Homologous features are the features that are similar in different organisms having similar embryonic origin and development and are inherited from a common ancestor that also had that feature. Also, they might have different functions. An example is the presence of four limbs in tetrapods such as crocodiles, birds, etc.
- Analogous features are the features that are superficially similar in different organisms but had separate evolutionary origins i.e., different in origin, but similar in function. An example includes the wings on a fly, a moth, and a bird where the wings were developed independently as adaptations to perform the common function of flying.
- Polygenic features are the traits or features that are controlled by multiple genes that are located on the same or different chromosomes and are also affected by the environment. These features do not follow Mendel’s pattern of inheritance and are represented as a range of continuous variation. Examples of polygenic traits or features include skin color, height, hair color, eye color, etc. For example, there is wide variation in the human skin color (from light to dark) and height (short or tall or somewhere in between).
- Sympatry describes a species or a population that inhabit the same geographic region at the same time. In sympatric speciation, new species are evolved from a surviving ancestral species while both the species inhabit the same place at the same time i.e., in a single population, reproductive isolation occurs without geographic isolation.
Answer:
Lower liver border.
Explanation:
The liver is in the upper right side of the abdomen, above it is the diaphragm, beneath is the right kidney, the stomach, and the intestine. If we position our hands on the right clavicular line and bellow the umbilicus, as we move them, we will be able to locate the liber when we arrive at the upper right side of the abdomen and feel if there is any problem.
