midterm review - whsd.k12.pa.us
TRANSCRIPT
Midterm Review
Chapter 1
Biology and You
7 Characteristics of Living Things
1. Cellular organization
2. Reproduction
3. Metabolism
4. Homeostasis
5. Heredity
6. Responsiveness
7. Growth & development.
Levels of Organization in
Living Things
1. Organelles
2. Cells
3. Tissues
4. Organs
5. Organ system
6. Organism
Science vs. Biology
• Science
Process of thinking & learning about the
world
• Biology
Study of life
Steps of the Scientific Method
1. State the problem based on observations.
2. Research the problem.
3. Form a hypothesis.
4. Test the hypothesis (experiment).
5. Collect and analyze the data.
6. Form a conclusion.
7. Report the results.
Control vs. Variable
• Control
The standard of comparison for the
experimental group
Receives no experimental treatment
• Variable
The one factor that differs among the
test groups.
Part of the experimental group
Independent vs. Dependent
Variable
• Independent variable – factor changed
by the experimenter (the factor tested)
- a good experiment tests one
variable.
• Dependent variable – factor that
depends on the value of the
independent variable (a result
measured).
Independent vs. Dependent
Variable
Observations
• Qualitative
Observations that deal with the
characteristics of the object such as
hardness, texture, beauty, etc.
• Quantitative
Observations that deal with numbers
such as the mass, how many, how long,
etc.
Theory vs. Hypothesis vs.
Prediction• Theory
A set of related hypotheses that have been tested and
confirmed many times by many scientists.
Unites and explains a broad range of observations.
• Hypothesis
An educated guess based on observations & research
that can be tested.
• Prediction
Expected outcome of a test assuming the hypothesis
is correct.
Base Units of the Metric System
• Meter
Measures length
• Liter
Measures volume
• Gram
Measures mass
• Celsius
Measures temperature
Chapter 6: Chromosomes
& Cell Reproduction
Section 1: Chromosomes
Chromosomes
• Chromosomes are DNA & its
associated proteins.
We have 46 chromosomes or 23
pairs of chromosomes.
• In a prokaryotic cell, it is the
main ring of DNA.
Autosomes vs. Sex Chromosomes
• Autosomes are any chromosomes that are
not directly involved in determining the
sex of an individual.
We have 22 pairs.
• Sex chromosomes contain genes that will
determine the sex of the individual.
We have one pair.
Females are XX.
Males are XY.
Gametes
• Gametes are an organism’s
reproductive cells.
Female’s gametes are eggs or ova.
Male’s gametes are sperm.
Haploid vs. Diploid
• Haploid refers to a cell (gamete) that
contains only 1 set of chromosomes.
It is represented by “n.”
• Diploid refers to a somatic or body
cell that contains 2 sets of
chromosomes.
It is represented by “2n.”
Karyotype
• A karyotype is a photo of the
chromosomes in a dividing cell that
shows the chromosomes arranged by
size.
A trisomy at 21 indicates the individual
has Down syndrome.
Chapter 27
Introduction to Animals
General Features of Animals
• Heterotrophy – must consume other
organisms
• Mobility – able to perform rapid, complex
movements (swim, crawl, walk, run, fly)
• Multicellularity
• Diploidy – have 2 copies of each
chromosome
• Sexual Reproduction – produce gametes
which unite.
General Features of Animals
• Absence of a cell wall – allows for
mobility
• Blastula formation – fertilized egg
undergoes cell divisions that form a hollow
ball of cells
• Tissues – cells of all animals except
sponges are organized into structural and
functional units called tissues
Primary Tissue Layers of
Blastula
• Ectoderm– Gives rise to the outer layer of skin; nervous system;
sense organs, such as eyes
• Endoderm – Gives rise to lining of digestive tract; respiratory
system; urinary bladder; digestive organs; liver; many
glands
• Mesoderm – Gives rise to most of the skeleton; muscles; circulatory
system; reproductive organs; excretory organs
3 Types of Body Symmetry
• Asymmetrical – irregular in shape
( ex: sponge)
• Radial symmetry – body parts arranged
around a central axis; aquatic animals
(ex: sea anemone)
• Bilateral symmetry – body design in
which there are distinct right and left
halves (ex: humans)
Cephalization
• An anterior concentration of sensory
structures and nerves
• Animals with cephalic ends, or heads, are
often more active and mobile.
• It also allows animals to more easily sense
food and danger.
Phylogenetic Trees
• A branching diagram
• Shows how organisms are related through
evolution.
• Clues to a phylogenetic tree come from:
– Fossil record
– Comparative anatomy & physiology
– Comparative embryology
– Comparing DNA – most direct evidence
Gastrovascular cavity vs. digestive tract
• Gastrovascular cavity:
– One opening
– No specialization b/c every cell is exposed to
all stages of digestion
• Digestive tract:
– Two openings – a mouth and an anus
– Food moves in one direction
– Allows for cell specialization
Asexual vs. Sexual Reproduction
• Asexual Reproduction:
– Does not involve the fusion of 2 gametes
– Offspring identical to parent
– Examples: fragmentation, binary fission &
parthenogenesis
• Sexual Reproduction:
– Involves the fusion of a male and female
gamete
– Gives rise to genetic variation
Levels of Organization Again!
• Organelle
• Cell
• Tissue
• Organ
• Organ system
• Organism
Tissue Types and their Functions
• Epithelial tissue
– Protects other tissues from dehydration
and physical damage
– Ex: skin; membranes
• Nervous tissue
– Carries information throughout the body
– Ex: brain, spinal cord, nerves
Tissue Types and their Functions
• Connective tissue
– Support, protect & insulate the body
– Ex: fat, cartilage, bone, tendons, &
blood
• Muscle tissue
– Enable the movement of body structures
by muscle contraction
– Ex: skeletal, smooth and cardiac muscle
Organ Systems & their
Functions
• Circulatory system –
transports nutrients,
waste, hormones and
gases.
Organ Systems & their
Functions
• Digestive system –
Extracts and absorbs
nutrients from food;
removes waste;
maintains water and
chemical balances
Organ Systems & their
Functions
• Immune system –
defends against
pathogens and disease
Organ Systems & their
Functions
• Integumentary system (Skin) – Protects
against injury, infection and fluid loss;
helps regulate body temperature
Organ Systems & their
Functions
• Muscular system –
moves limbs and
trunk; moves
substances through
the body; helps with
providing structure
and support
Organ Systems & their
Functions
• Nervous system –
regulates behavior;
maintains
homeostasis;
regulates other organ
systems; controls
sensory and motor
function
Organ Systems & their
Functions
• Reproductive
system – produces
gametes and
offspring
Organ Systems & their
Functions
• Respiratory system
– moves air into
and out of the
lungs; controls gas
exchange between
blood and lungs
Organ Systems & their
Functions
• Skeletal system – protects and supports
body organs and produces blood cells
Stem Cells
• Capable of becoming any type of tissue
found in the adult body
• Embryonic stem cells offer the possibility
of repairing damaged tissues
Chapter 2
Chemistry of Life
Atom and Its Parts
• An atom is the smallest unit of an element that maintains the properties of that element.
Nucleus contains:
Proton (+)
Neutron (Neutral)
Electron cloud
Electron (–)
Covalent vs. Ionic Bonds
• Covalent Bond
Bond formed when atoms share pairs of
electrons.
• Ionic Bond
Bond formed by the attraction between
oppositely charged ions.
Covalent vs. Ionic Bonds
Molecules and Polar Molecules
• Molecule
A group of atoms held together by
covalent bonds.
• Polar Molecule
Shares its electrons unequally and
therefore has partially positive and
negative ends, or poles.
Water is a polar molecule.
Molecules and Polar Molecules
Solvents
• Solvent
A substance, usually a liquid,
capable of dissolving another
substance.
• Universal Solvent
Water.
pH Scale and Acids & Bases
• pH Scale ranges from 0 - 14
Acid
A compound that forms hydrogen ions (H+) in water.
Its pH is 0 to less than 7. (0 to < 7)
Base
A compound that forms hydroxide ions (OH-) in water.
Its pH is greater than 7 to 14. (>7 to 14)
Neutral
Substances that have a pH of 7.
Organic Macromolecules
• Organic macromolecules:
Contain carbon atoms that are covalently
bonded to other elements – typically
hydrogen, oxygen and other carbon atoms.
4 principal classes of organic compounds
found in living things are:
Carbohydrates
Lipids
Proteins
Nucleic acids
Organic Macromolecules
• Carbohydrates – organic compounds made of
carbon, hydrogen and oxygen in a 1:2:1 ratio.
Monomers are monosaccharides.
Ex: Glucose and fructose
Polymers are polysaccharides.
Ex: Starches, potatoes, paper, crab shells
Functions
Stores energy.
Makes up cell walls in plants and fungi.
Makes up exoskeleton in some animals.
Organic Macromolecules
• Lipids are nonpolar molecules that are insoluble in water & include fats, phospholipids, steroids and waxes.
Monomers are glycerol & fatty acids
Polymer examples
Butter & oil
All membranes
Cholesterol and Steroids
Functions
Stores energy
Makes up cell membranes
Acts as chemical messengers
Organic Macromolecules
• Proteins
Monomers are amino acids
Polymer examples
Hemoglobin and antibodies
Muscle, hair and nails
Functions
Hemoglobin carries oxygen and antibodies help
defend against infection.
Make up tissues that support body structures and
provide movement
Speed up chemical reactions (enzymes)
Organic Macromolecules
• Nucleic acids
Monomers are nucleotides
Polymer examples
DNA
RNA
Functions
Controls cellular activities
Stores hereditary information
Plays key role in the manufacture of proteins
Catalyst vs. Enzyme
• Catalyst
Speeds up chemical reactions by
lowering the activation energy.
• Enzyme
Specialized protein that acts as an
organic catalyst.
Test Indicators & Positive Results
• Benedict’s solution
Tests for simple sugars – blue color changes to red, orange, yellow, green.
• Lugol’s iodine
Tests for starch – reddish–orange iodine turns blue-black or black.
• Biuret solution
Tests for protein – blue turns purple.
• BTB (Bromthymol blue)
Tests for CO2 – blue turns green, or yellow.
Chapter 3
Cell Structure
Microscopes
• Review the different types of microscopes and their uses.
• Review the parts and functions of a microscope
• To determine the total magnification of a microscope multiply the eyepiece (ocular lens) times the objective lens.
Cell Theory
1. All living things are made of one
or more cells.
2. Cells are the basic unit of
structure and function in
organisms.
3. All cells arise from existing cells.
Prokaryote vs. Eukaryote
• Prokaryote
No nucleus
No membrane bound organelles
Circular DNA
Relatively small
Reproduce quickly (20 min.)
Examples: Bacteria
Prokaryote vs. Eukaryote
• Eukaryote
Nucleus
Many membrane bound organelles
Linear DNA
Relatively large
Reproduce slowly (24+ hours)
Examples: Plants, animals, fungi &
protists
Cell Parts & Functions
• Cell membrane
Controls what enters & leaves a cell; separates & protects the cell from the environment.
• Nucleus
Contains the DNA in eukaryotic cells; controls cellular activities.
• Vacuole
Membrane bound sac that stores water, may also contain ions, nutrients & waste.
Cell Parts & Functions
• Chloroplast
Organelle that uses light energy to make carbohydrates from CO2 & H2O.
• Cytoplasm
Region of the cell within the membrane that includes the fluid, the cytoskeleton and all of the organelles except the nucleus.
• DNA
Material that contains the information that determines hereditary characteristics.
Cell Parts & Functions
• Ribosomes
Organelle composed of RNA & protein; site of protein synthesis.
• Mitochondrion
Cell organelle surrounded by 2 membranes & is the site of cellular respiration, which produces ATP.
• Cell Wall
Rigid structure that surrounds the cell membrane & provides support to the cell.
Chapter 4
Cells and Their
Environment
Diffusion vs. Osmosis
• Diffusion
The movement of particles from regions of higher concentration to regions of lower concentration.
Ex: perfume spreading across a room.
• Osmosis
The diffusion of water from an area of high concentration to an area of low concentration across a membrane.
Ex: Getting thirstier when you drink salt water.
Passive vs. Active Transport
• Passive Transport
Does not require energy.
Movement down the concentration
gradient.
Examples:
Diffusion
Osmosis
Facilitated diffusion
Passive vs. Active Transport
• Active Transport
Requires energy.
Movement against the concentration gradient.
Examples:
Sodium-potassium pump
Endocytosis
Phagocytosis
Pinocytosis
Exocytosis
Chapter 6: Chromosomes
& Cell Reproduction
Section 2: The Cell Cycle
Section 3: Mitosis and Cytokinesis
5 Stages of the Cell Cycle
5 Stages of the Cell Cycle
• The first 3 stages are collectively
called interphase. (90% of a cell’s
life is spent here.)
1. First growth (G1) phase
Cell grows rapidly & carries out
routine functions. (Major portion of a
cell’s life is spent here.)
5 Stages of the Cell Cycle
2. Synthesis (S) phase
Cell’s DNA is copied.
Each chromosome consists of 2 chromatids
attached at the centromere.
3. Second growth (G2) phase
Preparations are made for the nucleus to
divide.
Microtubules are rearranged.
Organelles are manufactured or reproduced.
5 Stages of the Cell Cycle
4. Mitosis
The nucleus of a cell divides into 2
nuclei each with the same # and kinds
of chromosomes as the original cell.
5. Cytokinesis
The cytoplasm divides and 2 new cells
are formed.
3 Checkpoints
• A checkpoint is an inspection point
at which feedback signals from the
cell can trigger the next phase of the
cell cycle or delay it.
1. Cell Growth (G1) checkpoint at the end
of the G1 phase
Makes the decision of whether or not a
cell will divide.
3 Checkpoints
2. DNA synthesis (G2) checkpoint at the
end of the G2 phase
DNA replication is checked by DNA
repair enzymes.
3. Mitosis checkpoint at the end of
mitosis
Triggers the exit from mitosis
4 Phases of Mitosis
1. Prophase
Chromosomes become visible.
Nuclear envelope dissolves.
The spindle forms.
In animal cells, the centrioles move to opposite poles and the spindle forms between them.
4 Phases of Mitosis
2. Metaphase
Chromosomes move to the center of the cell & line up along the equator.
Spindle fibers link the chromatids of each chromosome to opposite poles.
4 Phases of Mitosis
3. Anaphase
Centromeres divide.
The 2 chromatids (now called chromosomes) move toward opposite poles as the spindle fibers attached to them shorten.
4 Phases of Mitosis
4. Telophase
A nuclear envelope forms around the chromosomes at each pole.
The chromosomes uncoil and return to chromatin form.
The spindle dissolves.
Cytokinesis begins.
Cytokinesis
• Division of the cytoplasm of a cell
• Follows the division of the cell’s nucleus by mitosis or meiosis
• Cytokinesis in animal cells occurs when a belt of protein threads pinches the cell membrane in half.
• Cytokinesis in plant cells occurs when vesicles from the Golgi apparatus fuse to form a cell plate.
Cytokinesis
• Cytokinesis in Cytokinesis in
animal cells plant cells
Review the following labs:
• Compound Light Microscope Lab
• Cell Structure Lab (Lab 9)
• Diffusion Demo Lab
• Cell Processes: Osmosis & Diffusion
worksheet