Answer:
The above paragraphs describes that how salt- and fresh-water fish regulates their osmoregulation. Hence, the correct answer would be c. have adapted to deal with osmosis.
Osmosis is the process by which solvent's molecule move from region of low concentration (hypo-tonic) to the region of high concentration (hyper-tonic) through a semi-permeable membrane.
In sea-water fishes, the body fluids are hypo-tonic to the surrounding water and thus water is kept moving out of their gills. In order to prevent the excess water loss they need to drink water constantly and excrete concentrated urine.
In contrast, fresh-water fishes body fluids are hyper-tonic to surrounding water and hence, water keeps entering in their body through gills. So, in order to prevent excess dilution they absorb salt from surrounding with the help of gills and also their bodies reabsorb salt from urine.
Answer:
first drop down:
a. mass
second drop down:
b. weight
third drop down:
a. strength of gravity increases
fourth drop down:
b. weight decreases
The measure of variation which exists in the genetic makeup of any particular individual within a population is genetic variation. There are several key features and advantages associated with the genetic variation as it is an important factor causing evolution allowing natural selection thus leading to increase or decrease the frequency of alleles in a population.
The other factors causing genetic variation include random mating, mutation, random fertilization and recombination during meiosis between the homologous chromosomes.
The main advantage of genetic variation is it enables the individuals to adapt to environment as well as maintaining the survival of the population.
Based on the information on genetic variation we can conclude whether there is increase or decrease in the genetic variation of the population in the gene pool.
• A zebra migrates to join a different herd of zebras- Increase
• Competition for sunlight leads to taller trees- Decrease
• The DNA of a snake changes to make its venom stronger- Increase
• A grass-fire randomly sweeps through a population of buffalo and kills most of the animals- Decrease
B. comet
comets only have tails because the sun is shining its light on the ice and dust behind the comet
Hydrangeas flower color changes with the Ph of the soil
