UMBC UNIT I: BIOLOGY 141 EXAM
QUESTIONS AND ANSWERS
Chapter 1: How do an observation, hypothesis, and a prediction differ? - Answers -A
hypothesis is a testable statement to explain a phenomenon or a set of observations. A
prediction describes a measurable or observable result that must be correct if a
hypothesis is valid. An observation consists of receiving knowledge of the outside world
through our senses, or recording information using scientific tools and instruments.
Chapter 1: What makes a hypothesis useful for scientific investigation that try to explain
the natural world? - Answers -Forming a hypothesis means forming a proposed
statement that can make testable predictions. Saying that the hypothesis is true means
that the predictions you've made are also true. and vice versa.
Chapter 1: Give examples of hypothesis that are and are not scientifically useful. State
the null hypothesis that corresponds to each of your examples. - Answers -A hypothesis
that is not useful would be "all dinosaurs eat only cake." This is not scientifically useful
because there's no way to test it. A null hypothesis is the conclusion we're going to draw
if our hypothesis is incorrect. Possible conclusions could be our variable has no affect,
opposite affect, etc. A null hypothesis for "all dinosaurs eat cake" could be "no
dinosaurs eat cake" or "Dinosaurs eat cake and other things."
Chapter 1: What are the key steps in hypothesis testing? - Answers -1. State the null
hypothesis 2.State the alternative hypothesis 3. Select method of testing
Chapter 1: What are the essential characteristics of a scientific experiment? - Answers -
Independent variable (x), dependent variable (y), control groups, constants
(experimental conditions).
Chapter 1: Design an experiment to test the hypothesis that squirrels prefer nuts over
chicken wings. Specify which conditions should be held constant across all experiments
and describe one or more controls you would include. - Answers -State the hypothesis
as precisely as possible and the predictions it makes
2. Design an observational or experimental study that is capable of testing those
predictions
Large sample size, include control groups, have constant/equivalent experimental
conditions, repeatability
, Chapter 1: What is the difference between a hypothesis and a scientific theory? -
Answers -A hypothesis typically address more specific issues while a theory is an
explanation for a more general phenomenon.
Chapter 1: What is the hypothesis of Spontaneous Generation and how Does Cell
Theory challenge that hypothesis? - Answers -Spontaneous generation hypothesis
states that organisms could arise spontaneously under certain conditions while the cell
theory challenges that and states all organisms are made up of cells and cells can only
be created from preexisting cells (cells from cells hypothesis).
Chapter 1: Explain Pasteur's experiment, including the purpose of the swan-necked
flasks. - Answers -In order to test whether cells are created/aren't created from
preexisting cells he conducted an experiment. This experiment involved him setting up
two flasks: one with a normal neck with contact to the outside and another with a swan
necked shape neck. the swan neck shaped flask was purposefully designed so that the
cells in the flask wouldn't have contact to the outside. In both the flasks he placed
nutrients and boiled them. In the straight necked flask the cells that were boiled were
killed but preexisting cells from the air entered the flask forming new cells. In the swan
necked flask however, the cells that were boiled died and the preexisting cells form
outside entered the flask yet got stuck in the neck. This led to no cells being regrown in
the broth.
Chapter 1: Why does Pasteur boil the broth in both types of flasks? For each type of
flasks, what is the outcome predicted by Spontaneous Generation? By Cell Theory? -
Answers -Pasteur boiled the broth to kill any preexisting cells and to see whether the
broth needed contact form the outside cells to regrow or not. This experiment debunked
the spontaneous generation hypothesis and proved the cell theory.
Chapter 1: What observed patterns support the theory of evolution by natural selection?
Be sure to define the terms evolution and population in your answer. - Answers -
Evolution is a change in the characteristics of a population over time. A population is a
group of individuals of the same species living in the same area at the same time (fish,
lions, worms, etc.) The observes patterns were that species are related by common
ancestry and characteristics of species can be modified from generation to generation
(descent modification).
Chapter 1: What are the two conditions required for natural selection to occur. -
Answers -Individuals within a population vary in characteristics that are heritable--
meaning, traits that can be passed on to offspring. And in a particular environment,
certain version of these heritable traits help individuals survive better or reproduce more
than do other versions.
Chapter 1: How does artificial selection differ from natural selection? How would you
artificially select for a particular characteristic? - Answers -Natural selection occurs
when heritable variation in certain traits leads to improved success in reproduction.
Because individuals with these traits produce many offspring (fitness level) with the
QUESTIONS AND ANSWERS
Chapter 1: How do an observation, hypothesis, and a prediction differ? - Answers -A
hypothesis is a testable statement to explain a phenomenon or a set of observations. A
prediction describes a measurable or observable result that must be correct if a
hypothesis is valid. An observation consists of receiving knowledge of the outside world
through our senses, or recording information using scientific tools and instruments.
Chapter 1: What makes a hypothesis useful for scientific investigation that try to explain
the natural world? - Answers -Forming a hypothesis means forming a proposed
statement that can make testable predictions. Saying that the hypothesis is true means
that the predictions you've made are also true. and vice versa.
Chapter 1: Give examples of hypothesis that are and are not scientifically useful. State
the null hypothesis that corresponds to each of your examples. - Answers -A hypothesis
that is not useful would be "all dinosaurs eat only cake." This is not scientifically useful
because there's no way to test it. A null hypothesis is the conclusion we're going to draw
if our hypothesis is incorrect. Possible conclusions could be our variable has no affect,
opposite affect, etc. A null hypothesis for "all dinosaurs eat cake" could be "no
dinosaurs eat cake" or "Dinosaurs eat cake and other things."
Chapter 1: What are the key steps in hypothesis testing? - Answers -1. State the null
hypothesis 2.State the alternative hypothesis 3. Select method of testing
Chapter 1: What are the essential characteristics of a scientific experiment? - Answers -
Independent variable (x), dependent variable (y), control groups, constants
(experimental conditions).
Chapter 1: Design an experiment to test the hypothesis that squirrels prefer nuts over
chicken wings. Specify which conditions should be held constant across all experiments
and describe one or more controls you would include. - Answers -State the hypothesis
as precisely as possible and the predictions it makes
2. Design an observational or experimental study that is capable of testing those
predictions
Large sample size, include control groups, have constant/equivalent experimental
conditions, repeatability
, Chapter 1: What is the difference between a hypothesis and a scientific theory? -
Answers -A hypothesis typically address more specific issues while a theory is an
explanation for a more general phenomenon.
Chapter 1: What is the hypothesis of Spontaneous Generation and how Does Cell
Theory challenge that hypothesis? - Answers -Spontaneous generation hypothesis
states that organisms could arise spontaneously under certain conditions while the cell
theory challenges that and states all organisms are made up of cells and cells can only
be created from preexisting cells (cells from cells hypothesis).
Chapter 1: Explain Pasteur's experiment, including the purpose of the swan-necked
flasks. - Answers -In order to test whether cells are created/aren't created from
preexisting cells he conducted an experiment. This experiment involved him setting up
two flasks: one with a normal neck with contact to the outside and another with a swan
necked shape neck. the swan neck shaped flask was purposefully designed so that the
cells in the flask wouldn't have contact to the outside. In both the flasks he placed
nutrients and boiled them. In the straight necked flask the cells that were boiled were
killed but preexisting cells from the air entered the flask forming new cells. In the swan
necked flask however, the cells that were boiled died and the preexisting cells form
outside entered the flask yet got stuck in the neck. This led to no cells being regrown in
the broth.
Chapter 1: Why does Pasteur boil the broth in both types of flasks? For each type of
flasks, what is the outcome predicted by Spontaneous Generation? By Cell Theory? -
Answers -Pasteur boiled the broth to kill any preexisting cells and to see whether the
broth needed contact form the outside cells to regrow or not. This experiment debunked
the spontaneous generation hypothesis and proved the cell theory.
Chapter 1: What observed patterns support the theory of evolution by natural selection?
Be sure to define the terms evolution and population in your answer. - Answers -
Evolution is a change in the characteristics of a population over time. A population is a
group of individuals of the same species living in the same area at the same time (fish,
lions, worms, etc.) The observes patterns were that species are related by common
ancestry and characteristics of species can be modified from generation to generation
(descent modification).
Chapter 1: What are the two conditions required for natural selection to occur. -
Answers -Individuals within a population vary in characteristics that are heritable--
meaning, traits that can be passed on to offspring. And in a particular environment,
certain version of these heritable traits help individuals survive better or reproduce more
than do other versions.
Chapter 1: How does artificial selection differ from natural selection? How would you
artificially select for a particular characteristic? - Answers -Natural selection occurs
when heritable variation in certain traits leads to improved success in reproduction.
Because individuals with these traits produce many offspring (fitness level) with the
