This is an experiment where the researcher manipulates one variable, and control/randomizes the rest of the variables. It has a control group, the subjects have been randomly assigned between the groups, and the researcher only tests one effect at a time.
Answer: CHANNEL PROTEINS provide openings in the plasma membrane for substances to flow through without changing structure, and CARRIER PROTEINS allow passage of substances through the plasma membrane after undergoing a subtle change in shape.
Explanation: They are described thus:
A channel protein is a protein that allows the transport of specific substances across a cell membrane.
Carrier proteins are proteins that carry substances from one side of a biological membrane to the other. Many carrier proteins are found in a cell’s membrane, though they may also be found in the membranes of internal organelles such as the mitochondria, chloroplasts, nucleolus, and others.
The correct answers are as follows:
1. During cytokinesis, THE CELL MEMBRANE PINCHES IN TO FORM TWO NEW CELLS.
Cytokinesis is the physical process of cell division, it divides the cytoplasmic content of the parental cell into two new daughter cells. Cytokinesis takes place in both mitosis and meosis.
2. The correct order of the phases of mitosis are as follows: PROPHASE, METAPHASE, ANAPHASE AND TELOPHASE.
Mitosis is the process of cell division by which a cell is divided into two new cells. The process occurs in four basic stages and result in the formation of two new cells.
3. The following terms are related to sexual reproduction: MATING SYSTEM, GAMETE FORMATION AND AMPLEXUS.
Amplexus refers to the mating positions of frogs and toads during sexual reproduction. Mating system refers to the number of mating partners that an animal has during the mating period. Gamete formation is the process by which sex cells are made and it occurs in both male and female animals.
4. As a cell is preparing to divide by mitosis, the DNA MUST BE COPIED.
When a cell is getting ready to divide by mitosis, it will undergo a stage called interphase, during which the cell prepare for cell division. During interphase, the cell undergo some process and these include the copying of the DNA. The cell copies its DNA so that it has two copies of each strand.
Answer:
Zona fasiculata.
Explanation:
Zona fasiculata is present in the middle of the adrenal cortex lies beneath the zona glomerulosa. This layer produces the glucocorticoids especially cortisol that regulates the glucose metabolism.
The zona fasiculata layer can be easily determined historically. This layer of adrenal cortex contains the long cords or column cells and the cells are plump with liquid.
Thus, the correct answer is option (b).
