Download Unit Five the_cell

THE CELL
Unit six
Entry task
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Look through your notes and find the 6 steps of cell
division.
Animal and Plant Cell Questions
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2.
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4.
5.
What are the similarities and differences between
plant and animal cells (create a list of an answer
of at least 3-4 sentences)?
Why don’t animal cells need cell walls?
What does the cell wall do for the plant cell?
What does the chloroplast do?
What are the similarities and differences between
cellular respiration and photosynthesis (minimum of
3-4 sentences)?
Entry Task
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What’s the difference
between these two
cells?
Objectives
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Explain hybridization
Describe self-pollination and cross pollination and explain how they
are different
Understand the basic structure of DNA and how they encode for
protein molecules through RNA
Understand Meiosis
Understand Mutations
Know the three regions of growth on plants
Name three functions of cells
Understand the relationship between DNA, genes, and chromosomes
Explain how growth regulators are used on plants
Describe the sequencing of bases in DNA
Discuss environment versus heredity on plant growth
Vocabulary
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Abscisic Acid
Adenine
Alleles
Bases
Chromosome
Codons
Cytosine
Differentiation
Ethylene
Gametes
Genes
*Genome
* Guanine
* Hormone
* Metabolites
*Mitosis
*Morphogenesis
*Nucleotides
*RNA
*Senescence
*Thymine
Regions of Growth
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Growth usually takes place in two ways.
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Enlargement of a single seed, leaf, stem, root, or fruit
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Formation of new cells in a specialized part of the plant.
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Due to intake of water or other substances into previously formed
cells
If this region of the plant is destroyed, new growth will not occur.
Three areas of new growth
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Tips of stems (terminal bud) and roots
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Axils of leaves
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Increase length
Formation of new stems, leaves, and flowers
Cambium layer in stems and roots
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Puts growth (width) on tree trunks and branches
Concepts and components of growth
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Plants have the ability to create new growth in
regions called meristems.
Plants also have the ability to change their cells.
This process of cell change is called differentiation.
Cells
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All living material is made of cells or the chemical
products of cells.
Cellular biology states:
 All
living material is made up of cells or the product of
cells
 All cells are derived from previously existing cells; most
cells are created by cell division…sex organs are
created differently
 A cell is the most elementary unit of life.
 Every cell is bounded by a plasma membrane.
 All cells have strong biochemical similarities.
 Most cells are small, about 0.001 cm
What's a cell suppose to do?
Maintenance
 Synthesis of cell products
 Cell division
These functions require the cell to take in nutrients
and excrete waste.
ATP is the universal energy transfer molecule and is
created during photosynthesis!
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Morphogenesis
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All organisms begin as a single cell.
Through mitosis (division) and repeated cell growth,
organisms develop into an adult, containing billions
of cells.
A plant has many different types of cells. These
cells must go through differentiation into a
specialized cell type (leaf, stem, xylem, ect.)
Chromosome..what makes a cell a cell
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The genetic code found in cell is what defines the
shape that cell will take.
The information needed to program and guide the
growth is contained within chromosomes.
Each cell contains the SAME genetic information that
was present in the fertilized egg.
But each cell is different because of various
biochemical triggers that turn different genes on
and off to produce various proteins.
Mitosis
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Mitosis is the reproduction of cells in which the
genetic material of the cell is duplicated exactly.
The cells simply divide and produce new cells like
themselves (daughter cells).
Six steps of mitosis
1.
2.
3.
4.
5.
6.
Interphase
Prophase
Metaphase
Anaphase
Telophase
Interphase
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Genes contain the blueprint or code that determines
how the plant will look and interact with its
environment.
Not all plants have the same number of
chromosomes.
Genes are the basic unit of inheritance.
Genes are carried in the chromosomes in the
Gametes…egg or pollen.
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Genes are made of DNA.
Genes cause the production of enzymes, which
control chemical reactions in the plant, thus affecting
plant development and function.
For normal development and function, genes must
occur in pairs.
Genes are a pair of chromosomes that reside in the
nucleus of the cell.
Chromosomes in the nucleus of a certain cell contain
the same genetic information as the chromosomes in
every other cell.
 The
genes in the roots are the same as the genes in the
stem.
Description of genes
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The complete set of instructions for making a plant
is called its genome.
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of this as the blueprint of a house
The genome is found in every nucleus of the cell and
consists of tightly coiled threads of DNA and
proteins, organized into chromosomes.
There are 150 million bases found in DNA
If unwound and tied together the strands of DNA
would stretch more than 5 feet but would be 50
trillionths of an inch wide.
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For each organism the components of these slender
threads encode all the information necessary to
build and maintain life.
 This
is true for all life from bacteria to blue whale.
Structure of DNA
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DNA molecules consist of
two strands that wrap
around each other to
resemble a twisted ladder.
The sides are made of sugar
and phosphate molecules
and connected by rungs of
nitrogen containing chemical
bases.
DNA strands
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Each strand of DNA is a linear arrangement of
repeating similar units called nucleotides, which is
each composed of one sugar, one phosphate, and a
nitrogenous base.
The four different bases of DNA are called:
 Adenine
 Thymine
 Cytosine
 Guanine
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These strands are held together by a weak bond
between the bases creating a pair.
Each time a cell divides into two daughter cells its
full genome is duplicated.
During cell division each strand of DNA unwinds
and weak bonds are broken between base
pairs….the strands will separate.
Once strands are separate the base begins to pair
once again with their complementary base.
Base pairing
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These bases will ALWAYS pair with one another.
 Adenine
will pair only with thymine
 Cytosine will pair only with guanine.
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Each daughter cell receives one old and one new
DNA strand.
Cells following the base-pairing rules ensure that
the new strand is an exact copy of the old one.
This minimizes mutations
How the code works
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Each DNA molecule contains many genes, the basic
physical and functional units of heredity.
A gene is a specific sequence of nucleotide bases
whose order carry the information required for
constructing proteins, which provide the structural
components of cells and tissues.
Each three base code calls for specific amino acids
to bind to.
mRNA is used to create duplicate DNA
Control of growth
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What factors do you think control plant growth?
Control of growth
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What factors do you think control plant growth?
 Heredity
– controls species characteristics, sets limits to
size and rate of growth through enzyme production and
cell enlargement/division.
 Hormones- growth regulators. Organic chemicals
produced in specific area of the plant that causes a
physiological response.
 Cytokinins:
cell division
 Auxins: cell elongation
 Gibberellins: cell elongation
 Controls things like stems growing towards light, root growth,
fruit and flower development, and leaf enlargement.
 Nutrition-
growth regulator
 Water:
result of enlargement due to internal water pressure
(turgor).
 Calcium: interacts with auxin and cytokinins to regulate cell
division and elongation.
 Nitrogen: involved in the structure of chlorophyll, proteins,
auxins, and cytokinins
 Environment Temperature:
all physiological activities are directly related.
Warmer = more favorable.
 Cooler = sometimes needed for initial plant growth.
 Light: wavelength affects pigmentation in leaves.
More on hormones
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Auxins: primary control of growth through cell
enlargement.
Sometimes acts as both stimulator and inhibitor of
growth. Affect: shoot, buds, and roots.
 Also stimulate differentiation of cells
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Gibberellins: control cell elongation and division in
plant shoots
Cytokinins: cell division, cell enlargement, and
transportation of amino acids.
Review Questions: T/F
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The complete set of instructions for making an
organism is called its genome.
Differences in genetic makeup are often referred to
as genetic variation
The environment has little effect on the expression
of the gene pairs controlling a trait.
Review Questions: Short Answer
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Name the three functions of all cells.
List five basic assumptions about all cells
Name four general examples of plant hormone
What pairs with these bases: adenine, adenine,
cytosine, thymine, and adenine?
List three parts of plant where new cells continue to
be formed.
Review questions: Critical thinking
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Give an example of how heredity and the
environment interact to alter plant growth and
development.
Discuss three ways that plant hormones affect plants
or plant cells