Bio 11.1 and 11.2 LESSON

11.1 Cell Growth, Division, and
Reproduction

Learning Objectives

▪ Describe some of the difficulties a cell faces as it

increases in size.

▪ Compare asexual and sexual reproduction.

Surface-Area-to-Volume Ratio

Surface area = the amount of “covering” of the object

Volume = the amount of space inside the object; the amount
of space the object takes up

SAcube = l × w × 6

Vcube = l × w × h

1 cm × 1 cm × 6 = 6 cm2

1 cm × 1 cm × 1 cm = 1 cm3

Fill in the Blanks

Surface Area to Volume in Growing Cells

SA

V

24 cm2

8 cm3

SA

V

54 cm2

27 cm3

Fill in the Blanks

Ratio of Surface Area to Volume in Cells

Largest ratio

Smallest ratio

Reorder

Surface Area to Volume ratio is very important in cells. Order these cube-like cells from smallest to largest Surface Area to Volume Ratio.

smallest >>>>>> largest

1

2

3

• 1
• 2
• 3

Cell Growth Limitations

• Information crisis: too many demands placed on DNA

• Traffic problems: volume grows too fast relative to surface
area, material exchange is insufficient

Multiple Select

Which of these are problems as cells grow too large?

• too much ATP in cells

• too many demands on DNA

• material exchange is insufficient

  (traffic problems)

• material exchange happens too quickly

  (speeding problems)

Cell Division

• Produces two daughter cells
• Cell must replicate DNA before cell division.
• Dividing to make more, smaller cells keeps
surface area to volume ratio high.

Multiple Select

Which two of these are true of cell division?

• it keeps the

  surface area to volume ratio

  HIGH

• it keeps the

  surface area to volume ratio

  LOW

• two

  DAUGHTER cells

  are produced

• two

  PARENT cells

  are produced

Asexual Reproduction

• A single parent produces genetically identical offspring.

Multiple Choice

Which statement is true of asexual reproduction?

• A SINGLE parent produces genetically IDENTICAL offspring.

• A SINGLE parent produces genetically SIMILAR offspring.

• TWO parents produce genetically IDENTICAL offspring.

• TWO parents produce genetically SIMILAR offspring.

Sexual Reproduction

• Sexual reproduction involves the fusion of two separate
parent cells.

• Offspring inherit some genetic information from each parent.

Multiple Choice

Which statement is true about sexual reproduction?

• TWO parent cells fuse to produce offspring with genetic information from EACH parent.

• FOUR parent cells fuse to produce offspring with genetic information from EACH parent.

• TWO parent cells fuse to produce offspring with genetic information from ONE parent.

• FOUR parent cells fuse to produce offspring with genetic information from ONE parent.

Comparing Asexual and Sexual
Reproduction

Asexual

▪Produce many offspring in
short period
▪ Don’t need to find a mate
▪ In stable environments,
genetically identical offspring
thrive.
▪ If conditions change, offspring
not well adapted.

Sexual

▪ Relatively fewer offspring;
growth takes more time
▪ Need to find a mate
▪ In changing environments,
genetic diversity can be
beneficial.
▪ Offspring may be less well
adapted to current conditions.

Categorize

Options (6)

many offspring in a short period

no need to find a mate

only thrive in stable environments

fewer offspring with slower growth

need to find a mate

beneficial for changing environments

Organize these options into the right categories

sexual reproduction

asexual reproduction

11.2 The Process of Cell Division

Learning Objectives

▪ Explain the role of chromosomes during cell

division.

▪ Describe the main events of the cell cycle.
▪ Describe what happens during the phases of

mitosis.

▪ Investigate how daughter cells split apart after

mitosis.

Chromosomes

In prokaryotic cells, DNA is packaged into a single, circular
chromosome.

Multiple Select

Which two words describe chromosomes in prokaryotic organisms, like bacteria?

• multiple

• single

• circular

• X shaped

Chromosomes

In eukaryotic cells, DNA is packaged into multiple chromosomes.

duplicated chromosome

centromere

sister
chromatids

supercoils

coils

histone
proteins

nucleosome

DNA

double
helix

Multiple Choice

Which term best describes chromosomes in eukaryotic organisms, like plants and animals?

• single

• multiple

• circular

• rhomboid

Prokaryotic Cell Cycle

Prokaryotes undergo binary fission.

Multiple Choice

Which term best describes the binary fission?

• PROKARYOTIC cells SPLIT

• PROKARYOTIC cells COMBINE

• EUKARYOTIC cells COMBINE

• EUKARYOTIC cells SPLIT

Eukaryotic Cell Cycle

Eukaryotic cells have a more complex cell cycle than
prokaryotic cells.

M Phase

Cell division occurs during M phase.

Multiple Select

Which TWO are true of the eukaryotic cell cycle?

• MORE complex than prokaryotic cells

• LESS complex than prokaryotic cells

• cell division occurs in

  M PHASE

• cell division occurs in

  INTERPHASE

Prophase

The nucleus condenses and chromosomes become visible.
The spindle begins to form.

Multiple Select

Prophase is the first phase of mitosis.

What two events happen in prophase?

• chromosomes line up at the center of the cell

• chromosomes are pulled toward opposite sides of the cell

• spindle fibers begin to form

• chromosomes become visible

• the cell begins to split into daughter cells

Metaphase

Chromosomes line up at the center of the cell.

centrioles

centromere

chromosome

chromatid

Multiple Choice

Metaphase is the second phase of mitosis.

What event happens in metaphase?

• chromosomes line up at the center of the cell

• chromosomes are pulled toward opposite sides of the cell

• spindle fibers begin to form

• the cell membrane pinches in the center to form daughter cells

• the cell begins to split into daughter cells

Anaphase

Chromosomes move toward opposite poles.

individual
chromosomes

Multiple Choice

Anaphase is the third phase of mitosis.

What event happens in anaphase?

• chromosomes line up at the center of the cell

• chromosomes are pulled toward opposite sides of the cell

• spindle fibers begin to form

• the cell membrane pinches in the center to form daughter cells

• the cell begins to split into daughter cells

Telophase

The cell begins to divide into daughter cells.

nuclear envelopes
re-forming

Multiple Choice

Telophase is the final phase of mitosis.

What event happens in telophase?

• chromosomes line up at the center of the cell

• chromosomes are pulled toward opposite sides of the cell

• spindle fibers begin to form

• the cell membrane pinches in the center to form daughter cells

• the cell begins to split into daughter cells

Cytokinesis

In animal cells, the cell membrane pinches in the center to
form two daughter cells.

Multiple Choice

Cytokinesis happens after mitosis.

What event happens in cytokinesis?

• chromosomes line up at the center of the cell

• chromosomes are pulled toward opposite sides of the cell

• spindle fibers begin to form

• the cell membrane pinches in the center to form daughter cells

  (in animal cells)

• the cell begins to split into daughter cells

Mitosis Overview
List and describe the phases of mitosis.

1

2

3

4

Cytokinesis

Prophase

Metaphase

Anaphase

Telophase

Reorder

Put what happens in the four phases of mitosis in order.

(Phases are numbered in the diagram)

This question is worth significantly more points that the other questions - answer carefully.

• chromosomes become visible and spindle fibers form

• chromosomes line up at the center of the cell

• chromosomes move to opposite ends of the cell

• the cell begins to divide into daughter cells

1

2

3

4

• 1
• 2
• 3
• 4