Intro to Biology
Name two topics that are likely to be studied by biologists, and two areas of scientific study that would fall outside the realm of biology.
Topics: Human anatomy, genetics, microbiology,animal behavior and ecology
Areas outside biology: Physics, Chemistry, Astronomy, Geology,Engineering
A person notices that her houseplants that are regularly exposed to music seem to grow more quickly than those in rooms with no music. As a result, she determines that plants grow better when exposed to music. This example most closely resembles which type of reasoning?
Inductive reasoning
Atoms that vary in the number of neutrons found in their nuclei are called ________.
Lactose is a disaccharide formed by the formation of a ________ bond between glucose and
________.
Isotopes
glycosidic, galactose
Why can some insects walk on water?
-Because of surface tension resulting from cohesive forces between water molecules.
-Some insects( water striders) have long hydrophobic legs that spread their weight so that they don't break the surface.
a. List two examples of biologically important molecules do we consume in our diet along with their sources?
b. Why is it impossible for humans to digest food that contains cellulose?
a.Proteins: meat, beans, egg, fish , milk
Carbohydrates: cereals and grains, bread, vegetables
Fats and oils: nuts, seeds, vegetable oil, meat, fish
Nucleic acids: seafood, mushrooms, vegetables
b. Humans lack the enzyme cellulase, required to break down the B-1,4 glycosidic bonds holding glucose molecules in cellulose. Hence, it passes through the digestive system as fiber.
If scientists found a new organism on a distant planet, what criteria must that organism possess to be considered a living thing?
List two requirements of life and explain what they mean. (2-4 sentences)
Growth and development: Should be able to increase in size over time.
Homeostasis: Should be able to maintain stable internal conditions despite changes on the outside.
Cellular structure and composition: Consists of one or more cells that carry out essential functions.
Reproduction: Should be able to reproduce offsprings of its own kind to ensure continuation of life.
Response: Respond to stimuli.
If experimental results support a hypothesis, what is the next step of the scientific method?
A suggested and testable explanation for an event is called a ________.
Conclusion
Hypothesis
If xenon has an atomic number of 54 and a mass number of 108, how many neutrons does it
have?
54
What property of carbon makes it essential for organic life?
Carbon can form four covalent bonds, which allows carbon to build diverse, complex organic molecules (biomolecules) which are necessary for life.
Why are biological macromolecules considered organic?
Because organic molecules are characterized by having C-H bonds.
Describe the central dogma of Biology?
It describes the one way flow of genetic information within the cell: DNA to RNA to protein. DNA is transcribed into mRNA and that RNA is translated by ribosomes to build proteins.
What are the stages involved in the scientific method?
Observation
Question
Hypothesis
Experimentation
Analysis/ Results
Conclusion
What type of bonds are found in the following?
a. Adenine – thymine bond in DNA
b. Oxygen-Hydrogen bond of water
c. Salt (NaCl)
a.Hydrogen bond
b. Polar covalent bond
c. Ionic bond
Why is carbon so important in biology?
Because it can form four covalent bonds allowing it to create diverse, complex and stable molecules which are the building blocks of life.
1. Two complimentary DNA strands (polymers) base pair together in an antiparallel
conformation: one is arranged 5’→3’, the other from 3’→5’ (see the example in Question 1).
Using your knowledge of DNA base pairing, write the complimentary sequence to the following
DNA sequences:
a. 5’- ATCGGCATAGAA -3’
compliment: 3’- ________________-5’
b. 5’- GATAGGATAACATTA -3’
compliment: 3’-_______________-5’
2. Describe the similarities and differences between glycogen and starch.
1 a. TAGCCGTATCTT
b. CTATCCTATTGTAAT
2. Similarities:
Both are polysaccharides made of glucose.
Both function as energy storage molecules.
Both have branched structures.
Differences:
Starch is mainly stored in plant roots, tubers and seeds. Glycogen is stored mainly in liver and muscles.
Starch is the storage form of glucose in plants. Glycogen is the storage form of glucose in animals.
Starch breaks down slowly. Glycogen breaks down more quickly.
Starch is less branched(amylopectin) or unbranched (amylose). Glycogen is highly branched.
With your knowledge of the characteristics of life, explain how you know a plant is alive.
Can reproduce new plants, responds to stimuli, made up of cells, grows and develops, uses energy through photosynthesis. It exhibits traits that meet the requirements for it to be classified as as a living thing.
Decide if each of the following is an example of inductive or deductive reasoning.
a. All flying birds and insects have wings. Birds and insects flap their wings as they move
through the air. Therefore, wings enable flight.
b. Insects generally survive mild winters better than harsh ones. Therefore, insect pests will
become more problematic if global temperatures increase.
c. Chromosomes, the carriers of DNA, separate into daughter cells during cell division.
Therefore, each daughter cell will have the same chromosome set as the mother cell.
d. Animals as diverse as humans, insects, and wolves all exhibit social behavior. Therefore,
social behavior must have an evolutionary advantage
a. Inductive
b. Inductive
c. Deductive
d. Inductive
What are isotopes? List some applications of radioactive isotopes?
Isotopes are atoms of the same element with the same atomic/ proton number but different mass number as a result of the difference in the number of neutrons.
Applications:
Cancer treatment, sterilizing medical equipment, pest control, carbon dating
In order to maintain homeostasis your body must stay within a specific temperature range.
Which two properties of water assist with this?
High heat capacity- Water absorbs and retains heat well, preventing rapid temperature changes in the body.
High heat of vaporization: When sweat evaporates, heat is lost from the body, helping us to cool down.
a. What are the structural differences between RNA and DNA
b.What are the four types of RNA and how do they function?
a. DNA has a double helix structure. RNA is single stranded.
DNA has deoxyribose sugar. RNA has ribose sugar.
DNA has thymine. RNA has uracil.
DNA is mainly found in the nucleus. RNA is found in both the nucleus and cytoplasm.
DNA is large and stable. RNA is smaller and less stable.
DNA carries genetic information. RNA is responsible for protein synthesis.
You go for a long walk on a hot day. Give an example of a way in which homeostasis keeps your body healthy.
- To maintain homeostasis, your body begins to sweat.
-As sweat evaporates from your skin, your body begins to cool down, preventing overheating and keeping your internal temperature stable.
Although the scientific method is used by most of the sciences, it can also be applied to everyday
situations. Think about a problem that you may have at home, at school, or with your car, and apply
the scientific method to solve it.
Problem: My phone isn't charging.
Observation: My phone is plugged in but it isn't charging.
Question: Why isn't my phone charging?
Hypothesis: The charging cable may be broken, messed up or faulty.
Prediction(Optional): If I charge my phone with a different cable, the phone should charge.
Experiment: I try charging my phone with a different cable.
Results: The phone charges when I use a different cable.
Conclusion: My hypothesis was correct because the new cable charged my phone.
An ion with eleven protons, twelve neutrons, and a charge of +1 has an atomic number of:
11
When scientists talk about the search for life on distant planets, they are looking for chemical
signatures of water and organic molecules. Why would the presence of liquid water be important
in the search for distant life?
List one characteristic of water and explain how it might contribute to the presence or development of life. (1-2 sentences)
The presence of liquid water is important because water is vital for chemical reactions that support life such as transporting nutrients or enabling nutrients to interact.
Characteristics:
- High heat capacity, which helps regulate temperature and creates conditions that are favorable for life to exist or evolve.
Universal solvent, enabling chemical reactions that support life.
a.Compare and contrast saturated and unsaturated triglycerides.
b.The presence of organic molecules (carbon-containing) might suggest there is life on a distant planet, since the four types of biomolecules are all carbon-rich.
List two categories of biomolecules and name the monomer for each.
a. Similarities
Both are lipids.
Both store energy for organisms.
Differences:
Saturated has single bonds. Unsaturated has double bonds.
Saturated is usually solid at room temperature. Unsaturated is usually liquid at room temperature.
Saturated has straight fatty acid chains. Unsaturated has bent chains due to double bonds.
Saturated is found in butter, animal fat. Unsaturated is found in plant oils, nut, fish
b. Protein- Amino acid
Nucleic acid- Nucleotides
Carbohydrates- Monosaccharides
Lipids- Fatty acids and glycerol