UMBC UNIT I: BIOLOGY 141 EXAM
QUESTIONS WITH 100% CORRECT
ANSWERS LATEST VERSION 2025/2026.
Chapter 1: How do an observation, hypothesis, and a prediction differ? - ANS 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? - ANS 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. - ANS 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? - ANS 1. State the null hypothesis
2.State the alternative hypothesis 3. Select method of testing
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
,Chapter 1: What are the essential characteristics of a scientific experiment? -
ANS 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. - ANS 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? - ANS 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? - ANS 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. -
ANS 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
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, 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? - ANS 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. - ANS 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. -
ANS 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? - ANS 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 same traits, the traits increase in frequency and
evolution occurs. Artificial selection is different because it's the process by which humans use
animal breeding and plant breeding to produce desirable traits/phenotypic traits. For instance
you can choose which animal or plant males and females can sexually reproduce and have
offspring together.
Chapter 1: Explain how genotype determines phenotype. Your answer should include a
description and an illustration of the flow of genetic information in a cell. - ANS Genotype is
the genetic constitution of an individual organism. It is determined by how your genes work
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
QUESTIONS WITH 100% CORRECT
ANSWERS LATEST VERSION 2025/2026.
Chapter 1: How do an observation, hypothesis, and a prediction differ? - ANS 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? - ANS 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. - ANS 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? - ANS 1. State the null hypothesis
2.State the alternative hypothesis 3. Select method of testing
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
,Chapter 1: What are the essential characteristics of a scientific experiment? -
ANS 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. - ANS 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? - ANS 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? - ANS 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. -
ANS 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
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, 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? - ANS 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. - ANS 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. -
ANS 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? - ANS 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 same traits, the traits increase in frequency and
evolution occurs. Artificial selection is different because it's the process by which humans use
animal breeding and plant breeding to produce desirable traits/phenotypic traits. For instance
you can choose which animal or plant males and females can sexually reproduce and have
offspring together.
Chapter 1: Explain how genotype determines phenotype. Your answer should include a
description and an illustration of the flow of genetic information in a cell. - ANS Genotype is
the genetic constitution of an individual organism. It is determined by how your genes work
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
