Question

1. true/false: phospholipids make up the cell membrane.

a. true
b. false

1. true/false: nucleotides make up rna.

a. true
b. false

1. true/false: polysaccharides have many simple sugars that are connected together.

a. true
b. false

1. steroid molecules have four connected rings of carbon atoms.

a. true
b. false

1. which of the following is an organic compound?

a. $co_2$
c. sodium chloride
b. $h_2o$
d. protein

1. the first electron shell of an atom can hold a maximum of

a) 1 electron.
c) 4 electrons.
b) 2 electrons.
d )8 electrons.

1. the first electron shell of an atom can hold a maximum of

a)1 electron.
c)4 electrons.
b)2 electrons.
d)8 electrons.

1. cells in different tissues vary considerably. which of the following determines a cells specialized function?

a)the number of cells of that type.
c)shape.
b)size.
d)which genes it uses.
22.two functions of the cell membrane are.
a)housing the dna and accessing the dna.
c)to produce and break down secretions
b)enabling the cell to communicate and attach to other cells.
d)to provide cellular energy and to produce mitochondria.
23.mitochondria manufacture proteins.
a) true
b) false

Explanation:

1. Cell membranes are primarily composed of a phospholipid bilayer.
2. RNA is a nucleic acid, and its monomer building blocks are nucleotides.
3. Polysaccharides are complex carbohydrates formed by linking multiple monosaccharide (simple sugar) subunits.
4. The defining structural feature of steroid molecules is four fused carbon rings.
5. Organic compounds contain carbon-hydrogen bonds; proteins are large organic molecules, while CO₂, H₂O, and sodium chloride are inorganic.
6. The first (innermost) electron shell has a maximum capacity of 2 electrons, following the 2n² rule where n=1.
7. This is a repeat of question 19, with the same rule applying to the first electron shell.
8. Cell specialization is driven by differential gene expression; which genes are activated determines the cell's specific function.
9. Cell membranes facilitate cell-cell communication and adhesion, while DNA is housed in the nucleus, energy production is in mitochondria, and secretion production is in other organelles.
10. Ribosomes (free or bound to the ER) are responsible for protein synthesis; mitochondria produce ATP and have their own small genome but do not manufacture most cellular proteins.

Answer:

1. a. True
2. a. True
3. a. True
4. a. True
5. d. Protein
6. B) 2 electrons.
7. B)2 electrons.
8. D)Which genes it uses.
9. B)enabling the cell to communicate and attach to other cells.
10. b) False