Answer:
B
Explanation:
The fatty acid tails of phospholipids are hydrophobic – meaning they are ‘water-hating’. This is why they are in the middle of the bi-lipid layer of the cell membrane 'hiding' from the 'watery' environment of a cell. This poses a challenge in the diffusion of large and charged molecules across the membrane -such as sodium ions. Such molecules need transmembrane protein channels to help them cross the membrane. These are called integral proteins because they are part and parcel of the cell membrane. The cell membrane, in addition, also has glycolipids and glycoproteins on its surface that are significant in the identification of the cell by other cells.
In mitochondria, during cellular respiration
The one that is true is the last one that you listed
Answer:
The correct answer is -
The control group: the group of people with no supplements and kept inside.
The dependent variable: Vitamin D level in all groups.
The independent variable: the source of vitamin D (sun or tablets)
Explanation:
The control group of any experiment is the group of subjects that did not receive any type of treatment or did not manipulate by the independent variable. Here the group of 30 people that kept inside and did not get supplements is the control group.
The independent variable is a variable that directly affects the dependent variable by a change in the independent variable. In this experiment, the sunlight and vitamin D tablets are independent variables that affect the vitamin D level in people.
The dependent variable is a variable that is affected by the independent variable or depends on the independent variable, vitamin level is the dependent variable.
