Answer:
Natural selection disrupts the genetic equilibrium by favoring the genes for the traits that impart survival advantage to individuals.
Explanation:
Natural selection refers to the unequal survival rate of individuals of a population due to the presence of some beneficial adaptive genetic trait. These individuals are able to survive more and leave more progeny. Over generations, the population has increased number of these individuals leading to evolution of a population with different allele frequencies.
For example, the frequency of gene for antibiotic resistance in the bacterial population was increased once humans started using antibiotics to control the bacterial population. This led to the evolution of the bacterial population with antibiotic resistance.
Answer:
The strands of mRNA move through the ribosome from A site to the P site and exist at E site. The molecules of tRNA bind to the molecules of mRNA at the A site before moving P site where amino acids are attached to the end of the growing peptide chain.
Explanation:
Answer:
An inversion
Explanation:
An inversion occurs when a chromosome breaks in two places; the resulting piece of DNA is reversed and re-inserted into the chromosome. Genetic material may or may not be lost as a result of the chromosome breaks.
Answer:
Class I: Hepaticopsida ( Liverworts)
Class II: Anthocerotopsida ( Hornworts)
Class III: Bryopsida ( Mosses)
Explanation:
Bryophytes are small plants that grows in moist and shady places.They don't attain great heights because of absence of roots, vascular tissues, mechanical tissues and cuticle. They are terrestrial but require external water to complete their life cycle. Hence they are called as the" amphibians" of the animal kingdom.
Class I: Hepaticopsida or Hepaticae
- Gametophytic plant body is either thalloid or foliose. If foliose the lateral appendages are without midrib.
- Rhizoids without septa
- Each cell in the thallus contain many chloroplasts
- Sex organs are embedded in the dorsal surface
- Capsule lacks columella
- Sporophyte may be simple having only one capsule or differentiated into root, seta and capsule
- It has 4 orders: Calobryales, Jungermanniales, Spherocarpales and Marchantiales
Class 2: Anthocerotae or Anthocerotopsids:
- Gametophytic plant body is simple, thalloid;thallus dorsiventra without air chambers shows no internal differentiation of tissues
- Scales are absent in the thallus
- Each cell of the thallus possess a single large chloroplast with a pyrenoid
- Sporophyte is cylindrical only partly dependent on gametophyte for its nourishment. It is differentiated into bulbous foot and cyclindrical capsule. Seta is meristematic.
- Endotheciumforms the sterile central column in the capsule. It have ony one order Anthocerotales
Class 3: Musci or Bryopsida
- Gametophyte is differentiated into prostrate protonema and an erect gametophores
- Gametophore ids foliose, differentiated into axis and lateral appendages like leaves but without midrib.
- Rhizoids are multicellular with oblique septa
- Elaters are absent in the capsule of sporangium
- The sex organs are produced in seperate branches immersed in a group of leaves.
- It has only three orders: Bryales, Andriales and Sphagnales
Bryophytes are used as a packaging material for fragile goods, glasswares etc.Mosses are good source of animal food in rocky and snow clad areas. Decoction prepared by boiling Sphagnum in water is used for the treatment of eye disease.
