The correct answer is 9:3:3:1
When two homozygotes for two traits cross, the phenotypic ratio of the offspring is 9:3:3:1 ( unless other factors like epistatic interaction change the inheritance model).
In our case, we have two simple traits of seed color and seed shape that follow the Mendelian model of inheritance.
In this dihybrid cross, we have
9/16 of the offspring expressing both dominant traits ( yellow and round seeds)
3/16 expressing one dominant and one recessive trait ( yellow and wrinkled)
3/16 expressing the other dominant and recessive trait (green and round)
1/16 expressing both recessive traits ( green and wrinkled)
The altered protein affected the function of the cell membrane. The cell membrane which contain a bilayer control the movement of substance in and out of the cell and organelles. Due to this it is selective permeable to ion and organic molecules.
Answer:
variation
Explanation:
Genetic variation is what makes us all unique as a result of subtle changes in our DNA. The Theory of Evolution is a process in which organisms change over time as a result of adapting to their environment. Charles Darwin came up with the term Survival of the fittest, in any environment plants and animals from the same species show natural variation in their physical characteristics, like neck lengths in giraffes. Darwin suggested that the plants and animals best suited to the environment will survive and pass on their characteristics to their offspring. Over time, the characteristics of the surviving members of the species will become predominant.
Example: Peppered moth
In London in the 1800's, 98% of peppered moths had light colored bodies and only 2% were dark. The light moths were the same color as the trees so they could easily hide from hungry birds and not get eaten. The dark moths however were easy to see and were eaten. Then came the factories and smoke of the industrial evolution and many trees turned black with soot and suddenly the dark moths were able to survive better as they now looked like the trees and the light colored moths were easier to spot and eat. By 1895 the dark peppered moths made up 95% of the population and the light colored moths only 5%. This is an example of natural selection, because of the gene that makes the moths dark, it allowed them to flourish when the environment changed, they adapted, reproduced and survived.
When the stomach is stimulated, its environment would be describe as
acidic. The stomach releases proteases enzyme and hydrochloric acid to help in
digestion. The presence of hydrochloric acid will maintain low pH of the
stomach, which make the enzyme proteases to work best in cleaving proteins.
After the meal has been digested, the stomach pH returns to its resting level. Therefore,
the stomach secretes acid in response to food that aids in proper digestion.
Answer:
1) Trilobites
2) Jaw-less fish
3) Bony fish
4) Amphibians
<em>Note: May have gotten 2 and 3 mixed up.</em>