Semester Exam Review

SEMESTER EXAM REVIEW

Scientific Methodology: Hypothesis

Hypothesis: a tentative scientific explanation that can be
tested further

Designing Controlled Experiments

Many scientific discoveries are made from using them.

Controlled experiments: keep one aspect of the
experiment variable while keep many other aspects the
same.

Copyright Pearson Prentice Hall

Why is only one independent
variable chosen?

(manipulated) (responding)

Multiple Choice

Ultraviolet light may cause skin cancer is an observation. Identify the independent variable.

• People with fair skin

• Getting skin cancer

• Genetic mutations because of UV light

• Amount of ultraviolet light.

Multiple Choice

Ultraviolet light may cause skin cancer.

What could the formal hypothesis be?

• If you have fair skin, then you will get skin cancer because UV light causes skin cancer.

• Skin cancer will develop when exposed to UV light.

• If our skin is exposed to UV light then we may develop skin cancer because UV light causes genetic mutation leading to cancer cells.

Multiple Choice

If you give chocolate to your teacher, then the amount of homework will decrease because your teacher will be busy eating chocolate and not giving homework. :)

Identify the dependent variable.

• Giving chocolate to your teacher

• Amount of homework

• Amount of happiness in your teacher

• How busy your teacher is.

Copyright Pearson Prentice Hall

The distribution of shared electrons is uneven.
As a result water is a polar compound - it has
a plus side and a minus side

Copyright Pearson Prentice Hall

Hydrogen Bond= bond between weakly charged
molecules
● water molecules stick together using hydrogen bonds
● this attraction will result in remarkable properties

Multiple Choice

Which of the following is an example of COHESION?

• water sticking to water

• water sticking to glass

• oil sticking to plastic

• hydrogen sticking to oxygen

Multiple Choice

Water is polar. What does that mean?

• it is a molecule with opposite charges on opposite ends

• it is a molecule with no charge

• it is a molecule with identical charges on opposite ends

• it is a molecule with too many protons

Multiple Choice

A water strider can skate along the top of a pond because:

• covalent bonds result in water cohesion (surface tension)

• hydrogen bonds result in water cohesion (surface tension)

• water striders have adapted to take advantage of water cohesion

• water striders are afraid of water and avoid it

•The pH scale measures how acidic
or basic a solution is.

• The pH scale ranges from 0 to 14,

with 0 the most acidic and 14 the
most basic.

• Each pH unit represents a 10-fold

change in the concentration of H+ in
a solution.

• ex: pH 3 is 100x stronger than pH 5

( each step is 10 so 10 X 10 =100)

© 2015 Pearson Education, Inc.

Acids, Bases, and pH. Oh My!

2.14 The chemistry of life is sensitive to
acidic and basic conditions

•A buffer is a substance that minimizes changes in
pH when acids or bases are added.
•Buffers

• accept H+ when it is in excess and
• donate H+ when it is depleted.

•Controlling pH is important for
maintaining homeostasis.

© 2015 Pearson Education, Inc.

Multiple Choice

What does pH measure?

• the amount of hydrogen (H⁺) ions

• the amount of hydroxide (OH^-) ions

• amount of water

• all of the above

Multiple Choice

A substance with a pH of 8 is...

• a weak base

• a weak acid

• a strong base

• a strong acid

Multiple Choice

Which pH has the most hydrogen ions (H+)?

• 2

• 7

• 10

• 13

Multiple Choice

How is our body able to maintain a consistent pH (acidity level) even when the food we consume can be very acidic?

• Buffers in our body resist a change in pH

• Our diets naturally have a constant pH

• Water is resistant to a change in pH

Biotic and Abiotic Factors

Eosystem

(Biotic and Abiotic)

Biotic Factors

Abiotic Factors

all living parts, such
as plants, animals,
and bacteria.

the nonliving parts of
the environment, such
as water, air, and
rocks.

Food Webs

A food web is a network of feeding
interactions, through which both energy
and matter move.

Pyramid of Energy: ONE WAY FLOW

Biological Magnification

Toxic chemical magnifies as you move up the food chain

Trophic Cascade or “Top-Down”

Controls on lower trophic levels from higher levels.

Keystone Species

A keystone species plays a vital and unique role in
maintaining structure, stability, and diversity in an ecosystem

Multiple Choice

Identify a primary consumer in this food web.

• grass

• squirrel 

• vulture

• cougar

Multiple Choice

grass --> grasshopper --> sparrow --> hawk

In the food chain above, which organism would be found on level B of the energy pyramid shown?

• grass

• grasshopper

• sparrow

• hawk

Multiple Choice

Organisms that must eat other things to obtain energy are known by which term?

• heterotrophs

• autotrophs

• metamorphosis

• eaters

Multiple Choice

Non-living factor that affects an ecosystem

• biotic factor

• abiotic factor

• food chain 

• biome

Multiple Choice

An organism's place in the biotic environment and its role in an ecosystem is

• Habitat

• Habit

• Niche

• Community

Multiple Choice

A species that plays a critical role in the health, maintenance, growth, or definition of an ecosystem.

• keystone

• invasive

• engineer

• predator

Multiple Choice

A symbiotic relationship where one species obtains food or benefits from another species without benefitting or harming the other.

• Commensalism

• Mutualism

• Competition

• Parasitism

Multiple Choice

A symbiotic relationship that benefits both members of two different species.

• Predator-Pray

• Commensalism

• Mutualism

• Parasitism

Multiple Choice

No two species can occupy the same niche

• Competitive Exclusion Principle 
• Limiting Exclusion Theory
• Competitive Limiting Principle
• Limiting Competitive Theory 

The Cell Theory

• All living things are made up of cells.
• Cells are the basic units of structure and function in

living things.

• New cells are produced from existing cells.

Two Cell Types: Prokaryotes and Eukaryotes

Nucleus

Nucleus

Cell Membrane

Cell Membrane

Cell Membrane

Although it has no nucleus, does a prokaryotic cell have
genetic material or DNA?

Measuring Size undera Microscope

Multiple Choice

Which statement is part of the Cell theory?

• All living things have hair.

• All living things are made of cells and come from other cells.

• The cells of all living things have chloroplast.

• All living things can move. 

Multiple Choice

The main difference between prokaryotic and eukaryotic cells? 

• Prokaryotic cells have a cell membrane but eukaryotic cells do not.
• Eukaryotic cells contain DNA in a nucleus while prokaryotic cells do not.
• Eukaryotic cells have flagella but prokaryotic cells do not.
• Prokaryotic cells contain membrane-bound ribosomes while eukaryotic cells do not. 

Multiple Choice

You are looking at a slide with the scanning objective lens and your image is unfocused. Which knob would be best to adjust?

• Coarse Focus Knob

• Fine Focus Knob

• Diaphragm

• Eyepiece lens

Multiple Choice

True or false: You should NEVER adjust the coarse focus knob after you have switched to the HIGH power objective lens.

• True

• False

Multiple Choice

The eyepiece lens magnifies 10x and the low power lens magnifies 10x. What is the total magnification of the specimen under the microsco

• 10x larger

• 100x larger

• 40x larger

• 400x larger

Multiple Choice

If you are looking at the high power field of view (450μm), then what is the size of one of these cheeks cells (in yellow) in μm?

• 30

• 50

• 100

• 2

Copyright © 2020 Pearson Education, Inc. All Rights Reserved.

Membranes Are Fluid Mosaics

• Biologists use the fluid mosaic model to describe a

membrane’s structure—diverse protein molecules
suspended in a fluid phospholipid bilayer.

• The plasma membrane exhibits selective permeability.

Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved

Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved

Multiple Choice

What is it called when large molecules move across the cell membrane from an area of high concentration to an area of low concentration through a protein channel?

• Diffusion

• Osmosis

• Active Transport

• Facilitated Diffusion

Multiple Choice

The cell membrane is made mostly of

• phospholipid monolayer and proteins

• phospholipid bilayer and proteins

• proteins and carbohydrates bilayer

• triglycerides and carbohydrates

Multiple Choice

What is diffusion

• The movement of small particles from an area of high concentration to an area of low concentration

• The movement of large particles from an area of high concentration to an area of low concentration

• The movement of small particles from an area of low concentration to an area of high concentration

• The movement of large particles from an area of low concentration to an area of high concentration

Multiple Choice

to pump a solute across a membrane against its gradient requires work; the cell must expend energy

• active transport

• passive transport

• osmosis

• gated channels

Multiple Choice

If you looked at red blood cells under a microscope and saw the blood cells exploded, what would you say happened?

• The cells were placed in a hypotonic solution.

• the solution was isotonic.

• The solution was hypertonic.

Multiple Choice

This takes substances into a cell

• endocytosis
• exocytosis
• both

Copyright © 2020 Pearson Education, Inc. All Rights Reserved.

Leaf

Copyright © 2020 Pearson Education, Inc. All Rights Reserved.

Chromatography

Solvent Front

What takes place in the chloroplast?

Calvin
Cycle

Carbon dioxide + Water →Sugars + Oxygen

light

light

+
→
+

C6H12O6
6CO2
6H2O

6O2

Calvin cycle

electrons

NADPH

ATP
Sugars

converts

includes both

which

Photosynthesis

Chemical energy

H2O is split

energizes

electrons of
chlorophyll

CO2 is used

are passed

down

which takes place in

to

and

producing

to produce

by
facilitated
diffusion

NADP+ to

using

Sunlight

Light rxn

ETC

Stroma

Factors Affecting Photosynthesis

Important factors that affect photosynthesis include

1.

temperature- warmer temperatures are generally better

2.

light intensity - more light is generally better

3.

availability of water - less water is generally bad

Multiple Choice

Plants need carbon dioxide from their environment to produce glucose during which stage of photosynthesis? 

• The light-dependent stage

• The light-independent stage (The Calvin Cycle)

• The electron transport chain

• ATP formation

Multiple Choice

Most plants appear green because chlorophyll

• absorbs green light.

• absorbs violet light.

• does not absorb green light.

• does not absorb violet light.

Multiple Choice

Where do the light-dependent reactions occur? 

• thylakoid membrane

• stroma

• mesophyll

• mitochondria

Multiple Choice

Which organelle is responsible making food (Glucose) using sunlight?

• Cell Membrane

• Nucleus

• Chloroplast

• Mitochondria

Multiple Choice

What reactants are needed for the Calvin cycle?

• Carbon dioxide

• Carbon dioxide, ATP and NADPH

• Carbon dioxide and glucose

• Oxygen and water

Multiple Choice

Which of the following equations represents the overall chemical reaction for photosynthesis?

• 6O₂+ 6H₂O → C₆H₁₂O₆+ 6O₂

• C₆H₁₂O₆ + 6H₂O→ 6O₂+ 6O₂

• 6CO₂+ 6H₂O→ C₆H₁₂O₆+ 6O₂

• 6O₂ + 6H₂O→ C₆H₁₂O₆ + 6CO₂

Multiple Choice

What is the final product of Photosystem 1 

• NADPH

• ATP

• NADP+

• glucose

Multiple Choice

What is the function of NADP+?

• It absorbs light

• It is an electron carrier

• It is a light-reflecting pigment

• It acts as long-term energy storage

Multiple Choice

What are the two products of the light reactions that are needed for the calvin cycle?

• NAD and NADPH

• NADP + and Glucose

• NADPH and ATP

• Oxygen and NADPH