midterm review - whsd.k12.pa.us

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.


Functions

• Digestive system –

Extracts and absorbs

nutrients from food;

removes waste;

maintains water and

chemical balances


Functions

• Immune system –

defends against

pathogens and disease


Functions

• Integumentary system (Skin) – Protects

against injury, infection and fluid loss;

helps regulate body temperature


Functions

• Muscular system –

moves limbs and

trunk; moves

substances through

the body; helps with

providing structure

and support


Functions

• Nervous system –

regulates behavior;

maintains

homeostasis;

regulates other organ

systems; controls

sensory and motor

function


Functions

• Reproductive

system – produces

gametes and

offspring


Functions

• Respiratory system

– moves air into

and out of the

lungs; controls gas

exchange between

blood and lungs


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


• 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.


• 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


• 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)


• 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.


• 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.


• 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


• 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.)


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.


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

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midterm review - whsd.k12.pa.us

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