Question

13_independent practice: the cell cycle
humans begin as one cell called a zygote, but when babies are born they contain billions of cells and a fully - grown adult contains trillions of cells. this demonstrates which of the following?
a mitosis prevents babies from being born with too many cells.
b cell division is a primary factor in the growth of living things.
c mutations allow adult humans to contain more cells than other organisms.
d humans are the result of uncontrolled cellular division.

1. the process of mitosis and cellular division allows multicellular organisms to do which of the following?

a metabolize nutrients
c grow larger
b perform photosynthesis
d repair mutations

1. most of the life cycle of a cell is spent in interphase. interphase contains three stages, including the g₁ and g₂ stages. which of the following occurs during these gap stages?

a separation of chromosomes
c dna replication
b cellular growth
d viral transformation

1. during interphase, the dna is replicated to create two complete sets of dna. the dna is copied during which stage of the cell cycle?

a g₁
b s
c g₂
d m

1. dna can be replicated, the dna must separate -

a between the phosphate groups
c from the sugar - phosphate backbone
b behind the deoxyribose sugars
d between the nitrogenous bases

1. the process of dna replication is directed by dna polymerase molecules. dna polymerase would best be classified as which of the following?

a fatty acid
b enzyme
c nucleic acid
d glucose

1. dna replication occurs inside which of the following organelles?

a nucleus
b ribosome
c golgi body
d lysosomes

1. when dna replication is complete, each set of identical dna contains one of the cells original strands of dna paired with a newly constructed strand of dna. this method of dna replication is referred to as -

a facilitated copying
c transformational
b semi - conservative
d gene splicing

1. the purpose of mitosis is to separate the two sets of dna created during replication and -

a redirect the expression of genes
c place them into two nuclei
b discard the unwanted genes
d mutate them into new sequences

1. mitosis ensures that each new daughter cell that is created will be -

a genetically different from each other
c more complex than the original cell
b the exact same size and mass
d genetically identical to the parent cell

Explanation:

1. Humans start as a zygote and grow to have billions of cells. Cell division is key for growth, so B is correct. Mitosis doesn't prevent too - many cells (A), mutations don't cause more cells than other organisms in a general sense (C), and uncontrolled cell division is a problem not a normal growth process (D).
2. Mitosis and cell division help multicellular organisms grow larger (C). Metabolism of nutrients (A) is not directly related to mitosis, only plants do photosynthesis (B), and mitosis doesn't repair mutations (D).
3. During the G1 and G2 gap stages of interphase, cellular growth occurs (B). Separation of chromosomes is in mitosis (A), DNA replication is in S - phase (C), and viral transformation is not a normal part of these stages (D).
4. DNA is replicated during the S - phase of the cell cycle (B). G1 is for growth (A), G2 is for preparation for mitosis (C), and M is mitosis (D).
5. For DNA replication, the DNA must separate between the nitrogenous bases (D). Separation between phosphate groups (A), behind deoxyribose sugars (B), or from the sugar - phosphate backbone (C) is incorrect.
6. DNA polymerase is an enzyme (B) that directs DNA replication. It's not a fatty acid (A), nucleic acid (C), or glucose (D).
7. DNA replication occurs inside the nucleus (A). Ribosomes make proteins (B), Golgi body modifies and packages proteins (C), and lysosomes break down waste (D).
8. The method of DNA replication where each new DNA contains one original and one new strand is semi - conservative (B). Facilitated copying is not the term (A), transformational is not correct (C), and gene splicing is different (D).
9. The purpose of mitosis is to separate the two sets of DNA created during replication and place them into two nuclei (C). It doesn't redirect gene expression (A), discard unwanted genes (B), or mutate them into new sequences (D).
10. Mitosis ensures that each new daughter cell is genetically identical to the parent cell (D). They are not genetically different (A), not necessarily the exact same size and mass (B), and not more complex than the original cell (C).

Answer:

1. B. Cell division is a primary factor in the growth of living things
2. C. Grow larger
3. B. Cellular growth
4. B. S
5. D. between the nitrogenous bases
6. B. Enzyme
7. A. Nucleus
8. B. semi - conservative
9. C. place them into two nuclei
10. D. genetically identical to the parent cell