Function of Cell Division

Functions of Cell Division

D2.1.1 & D2.1.12*

D2.1.1 — Generation of new cells in living organisms by cell

Review: All life has the capability for reproduction

Even unicellular organisms like paramecium and chlamydomonas reproduce

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Review: Reproduction can be sexual or asexual

Asexual reproduction produces offspring that are genetically identical to the parent

Labeling

Match the following

Drag labels to their correct position on the image

Binary Fission

Mitosis

Eukaryotes

Prokaryotes

Review: Reproduction can be sexual or asexual

Sexual reproduction produces offspring that are genetically
unique and increases genetic variation within a species

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Form of cell division in sexual reproduction

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According to the cell theory, cells can only be
formed by division of

Review: According to the cell theory, cells can only be
formed by division of pre-existing cells

Implications of all cells being formed from pre-existing cells

#1 We can trace the origin of all
the cells in our body back to the
first cell

Multiple Choice

First cell in the human body

• zygote

• egg

• sperm

Multiple Choice

What type of relationship is shown in the graph?

• Linear

• Exponential

Implications of all cells being formed from pre-existing cells

#2 The origin of all cells can be
traced back through billions of
years of evolution to “LUCA” -
the last universal common
ancestor of all life on earth

Implications of all cells being formed from pre-existing cells

#3 There must have been a first cell that arose from non-living material

Implications of all cells being formed from pre-existing cells

#3 There must have been a first cell that arose from non-living material

How life originated and how the first cell came into being are matters of speculation (since these events cannot be reproduced in the laboratory)

Multiple Choice

The first cells were likely some sort of membrane surrounding a self replication molecule like a RNA

• True

• False

Multiple Choice

The first cells were likely some sort of membrane surrounding a self replication molecule like a RNA

• True

• False

Implications of all cells being formed from pre-existing cells

The first cells were likely some sort of membrane surrounding a self replication
molecule like a RNA

D2.1.12* — Cell proliferation for growth, cell repairment and tissue repair

Labeling

Match the following

Drag labels to their correct position on the image

Cell proliferation

Cell division

Cell growth

Multiple Choice

Cell Proliferation can only happen in

• unicellular organisms

• multicellular organisms

Cell Proliferation

• Process in multicellular organisms

• A cell grows and divides to produce daughter cells

Multiple Select

Cell proliferation occurs for:

• Organism growth

• Replacement of dead cells

• Tissue repair

Organism Growth

When plants and animals age, most also grow in size.

Cell proliferation creates the cells necessary to add more mass to the body.

Organism Growth - Animals

Most animals have an embryonic and juvenile phase of growth before reaching an adult size

Match

Match the following

• Embryonic Phase

• Juvenile Phase

• Adult Phase

3rd - 8week of pregnancy

growth after birth before reproduction

reach sexual maturity, can reproduce

• 3rd - 8week of pregnancy

• growth after birth before reproduction

• reach sexual maturity, can reproduce

Reorder

Reorder the following

• Embryonic Phase

• Juvenile phase

• Adult Phase

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2

3

• 1
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Embryonic Cell Proliferation is rapid

Cells omit growth phases (gap phases of interphase)

Labeling

Which phase is omitted for rapid embryonic cell proliferation?

Drag labels to their correct position on the image

Gap Phase (growth)

DNA Synthesis

Gap Phase (growth)

Mitosis (cell division)

Multiple Choice

As a result, the number of cells will:

• increase

• decrease

Multiple Choice

and the size of individual cells get

• smaller

• bigger

Open Ended

Why is it important for egg cells to be large in size?

Why are egg cells the largest cells?

All the cytoplasm and nutrients are supplied by the original cell

During juvenile growth

• Cells continue to proliferation

• With “spurts” of growth

Organism Growth - Plants

There is no limit to growth in plants

They can grow throughout their lifespan

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In plants, cell proliferation is confined to

regions

Labeling

Match the following functions to the meristem

Drag labels to their correct position on the image

widens the stem, adding thickness

for elongating stem, create leaf, flower

Creates cells for lengthening roots

Replacement of Cells that Die Naturally

An adult human has roughly 30 trillion human cells

●

72% (by mass) are fat and muscle

Open Ended

What is the little cell rule for life span?

Categorize

Options (5)

Fat tissue

Muscle tissue

Red blood cells

Cells lining the gut

Organize these options into the right categories

Last average of 12 to 50 years

Life span of 120 days

Life span of less than a week

I don't know

Replacement of Cells that Die Naturally - Red Blood Cells

• Life span is only about 120 days

• Must be replaced throughout an animal’s life

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Name the stem cells that differentiate / specialise into red blood cells

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Where are these stem cells located?

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Which organ is it found in?

Open Ended

What are the two functions of hematopoetic stem cell niche?

Replacement of Cells that Die Naturally - Skin

Because of continued cell
division behind him → cells
produce more keratin

Replacement of Cells that Die Naturally - Skin

Keratin causes the cell to toughen and dry out, so when
cells reach the skin surface → flattened and dead. Dead
skin will slough off the surface.

Reorder

Process of Replacement of Skin Cells that Die Naturally

• new cells are formed on the basal layer

• there is continued cell division - producing more keratin

• new cells push older ones up towards the skin surface

• keratin causes the cell to toughen and dry out

• dead skin cells are shed from the skin surface

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2

3

4

5

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Tissue Repair

During healing of injured tissue, cell proliferation occurs to replacement damaged cells

Important for skin and blood vessels

• Protection

• Bring oxygen and nutrients to other cells in the body

Tissue Repair: Skin during Wound Healing

A cut of burn of the skin will trigger
skin cell proliferation by:

• Basal cells in the epidermis

• Multipotent stem cells in the hair
  follicle (for deeper damage)

In certain organisms, cell proliferation can replace entire
lost limbs or tails

Quiz Time

Multiple Choice

What type of cell division occurs to create gametes used in sexual reproduction.

• Mitosis

• meiosis

• binary fission

• metastasis

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One implication of the cell theory is that we can trace all the cells in our body back to one cell formed after fertilization called a:

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One implication of the cell theory is that we can trace every cell on Earth back to a common, universal cell known as: 

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One implication of the cell theory is that there must have been a first cell that was created from abiotic components. This first, living cell on Earth is known as a:

Multiple Choice

Cell Proliferation refers to

• Cells that are dividing

• Cells that are growing

• Cells that are both dividing and growing

• Cells repairing themselves

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With embryonic cell development in animals, what is halted? 

Multiple Choice

The egg cell has a large volume relative to other cells. What function does that provide?

• The egg provides space for the embryo to grow

• The egg divides many times to produce a large number of cells

• The size of the egg makes it easy for sperm to fertilize

• The egg contains many cells that need nutrients

Multiple Choice

During what stage of development do animals experience the most growth?

• Embryo

• Fetus

• Infant

• Juvenile

• Adult

Multiple Choice

Cell proliferation in plants is confined to what tissue(s)? Pick any that apply

• Meristem

• Leaf

• Stem

• Flower

• Root

Reorder

Reorder the following based on life span

• Red Blood Cells

• Epithelial cells of the gut

• Fat muscle cells

• Skeletal muscle cells

• Lymphocytes

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2

3

4

5

• 1
• 2
• 3
• 4
• 5

Fill in the Blanks

Where are hematopoietic stem cells located in humans?

Multiple Choice

• The basal layer

• The spinous layer

• The granular layer

• The dermis

• The stratum corneum

Fill in the Blanks

In animals, deep injuries will trigger stem cells that are

potent to start cell proliferation

Multiple Choice

For plants and animals, does cell proliferation ever stop?

• Yes, it stops but only for animals when they reach adulthood; not plants

• Yes, it stops but only for plants when they reach a specific height; not animals

• No, cell proliferation never stops in either plants or animals

• Yes, cell proliferation stops for both plants and animals once maturation has stopped.