Question

1. which cell organelle is most directly involved with the bonding of amino acids?

a) endoplasmic reticulum
b) cell wall
c) mitochondrion
d) ribosome

1. which statement regarding the functioning of the cell membrane of all organisms is not correct?

a) the cell membrane forms a barrier that keeps all substances that might harm the cell from entering the cell.
b) the cell membrane controls the movement of molecules into and out of the cell.
c) the cell membrane is capable of receiving and recognizing chemical signals.
d) the cell membrane forms a boundary that separates the cellular contents from the outside environment.

1. the diagram below represents the fluid - mosaic model of a cell membrane.

the arrow points to a component of the membrane that is best described as a
a) lipid floating in sugars
b) lipid floating in proteins
c) protein floating in lipids
d) sugar floating in lipids

in multicellular organisms, cells must be able to communicate with each other. structures that enable most cells to communicate with each other are known as
a) chloroplasts
b) receptor molecules
c) antibiotics
d) pathogenic agents

sa 5) the diagram below represents a specimen on a slide with the low - power objective of a compound light microscope.
which type of cell is most likely represented in this diagram?

1. sa the diagram below represents a cell viewed using a compound light microscope.

select one of the lettered parts from the diagram. using one or more complete sentences, record the letter and state the function of the part you selected.

1. which procedure must be followed for the results of an experiment to be considered valid?

a) the results must be expressed in the form of a table or graph.
b) the experiment must be repeated a number of times to yield similar results.
c) after one trial, the results of the experiment must be published.
d) the data must include metric measurements.

Explanation:

1. Question 1: Ribosomes are the cellular organelles that perform translation, bonding amino acids together into polypeptide chains to make proteins.
2. Question 2: The cell membrane is semi-permeable, not a perfect barrier that blocks all harmful substances from entering the cell.
3. Question 3: The fluid mosaic model describes proteins embedded and floating within the phospholipid bilayer of the cell membrane.
4. Question 4: Receptor molecules on the cell membrane receive chemical signals to facilitate intercellular communication in multicellular organisms.
5. Question 5: The long, rectangular cell with a rigid cell wall visible in the low-power field is a plant (likely leaf epidermal) cell.
6. Question 6:

• C: Nucleus: It stores the cell's genetic material (DNA) and controls all cellular functions by regulating gene expression, directing protein synthesis and cell division.

1. Question 7: Experimental validity relies on repeatability: performing the experiment multiple times and getting consistent, similar results confirms the findings are not due to random chance.

Answer:

1. D) ribosome
2. A) The cell membrane forms a barrier that keeps all substances that might harm the cell from entering the cell.
3. C) protein floating in lipids
4. B) receptor molecules
5. Plant (leaf epidermal) cell
6. C: Nucleus, stores genetic material and directs cell activities
7. B) The experiment must be repeated a number of times to yield similar results.