Biology Key Concepts: Scientific Method, Cell Structure, DNA, and Ecosystems

Testing a hypothesis involves performing a what?

Experiment

What are the characteristics of the oxygen atom in a water molecule?

Slight negative charge, attracts hydrogen atoms of another molecule to form H bonds, attracts electrons more strongly than H atoms.

What are the steps in the scientific method of investigation?

Make observations, ask a question, form a hypothesis, test the hypothesis, draw conclusions, communicate results.

What method is used in scientific investigation?

Scientific method.

What is the best definition of biology?

The study of all living things.

What is homeostasis?

When living things maintain a constant, stable internal environment.

How is a cell best defined?

Basic units of structure/function of all living things.

What are the kingdoms of life?

Archaea, Bacteria, Protista, Fungi, Plantae, Animalia.

What are the unifying principles of biology?

Cell theory, gene theory, homeostasis, evolution.

What is an example of a scientific law?

Laws of motion.

What is the dependent variable?

The affected variable.

What is the independent variable?

The variable affecting the dependent.

What is an ecosystem?

A level of organization consisting of all living things in a given area, together with the nonliving environment.

What are the four nucleotides of the DNA molecule?

Adenine, Thymine, Cytosine, Guanine.

What are the subunits of complex carbohydrates?

Monosaccharides.

What are proteins made of?

Subunits called amino acids.

What are nucleic acids made of?

Subunits called nucleotides.

What is activation energy in a chemical reaction?

The energy needed to start a chemical reaction.

What three things do the activities of enzymes depend upon?

Temperature, ionic conditions, pH.

What is the difference between an endothermic reaction and an exothermic reaction?

Endothermic absorbs energy; exothermic releases energy.

What are three characteristics of a water molecule?

pH of 7, are polar, essential to life.

What pH range do acids have?

Under 7.

What is an atom?

The smallest particle of an element that still has the properties of that element.

What is a compound?

A substance that consists of two or more elements.

What are the characteristics of a compound?

Contain carbon, needed for life processes, found in most living things.

What are the characteristics of carbohydrates?

Store energy, energy provider, are sugars/starches.

What are the building block structures of proteins?

Amino acids.

Where do nucleic acids carry the genetic code?

In the sequence of nitrogen bases.

What are three structures found in all cells?

Plasma membrane, ribosomes, cytoplasm.

What is one main difference between eukaryotic and prokaryotic cells?

Eukaryotic cells have a nucleus.

Where are proteins made in the cell?

Ribosomes.

What does cytoplasm consist of?

Everything inside of the plasma membrane.

Which organelle transfers the energy in glucose to ATP?

Mitochondria.

What are three structures that contain DNA?

Nucleus, mitochondria, chloroplast.

What is the difference between active and passive transport?

Active transport needs energy; passive transport does not.

What is diffusion?

Movement of particles from high concentration to low concentration.

What is osmosis?

Diffusion of water.

What part of the cell determines what enters and leaves the cell?

Plasma membrane.

What are three types of passive transport?

Diffusion, osmosis, facilitated diffusion.

What is active transport?

Energy is used by the cell to change particles from low concentration to higher.

What is the basic unit of structure and function of all living things?

Cells.

What is referred to as all the material inside the plasma membrane of a cell?

Cytoplasm.

Why are viruses not considered to be living things?

Because they can't reproduce on their own.

What are plasma membranes composed of?

Phospholipids.

What molecules provide energy for active transport?

ATP.

What are examples of autotrophs?

Plants, algae, some bacteria.

What does photosynthesis use energy from to make food?

The sun.

What are the products of photosynthesis?

Glucose and oxygen.

What molecule contains too much energy for the cell to use?

Glucose.

What organisms form the basis of food chains?

Producers.

What is a heterotroph?

Living things that cannot make their own food.

What three things do the light reactions of photosynthesis require?

Sunlight, Chlorophyll, Water

What is the only product of the Calvin Cycle?

Glucose

List the steps in order of cellular respiration.

1 - Glycolysis, 2 - Krebs Cycle, 3 - Electron Transport

Where is the electron transport chain of cellular respiration located in the mitochondria?

Inner Membrane

What is the final electron acceptor of cellular respiration?

Oxygen

How many ATP molecules can be made from one glucose molecule?

38

What type of respiration was first to evolve?

Anaerobic Respiration

In the absence of oxygen, what is the most ATP molecules that can be produced from one glucose molecule?

2

What are the two types of fermentation?

Alcoholic and Lactic Acid

What stages of cellular respiration does fermentation involve?

Glycolysis

What does lactic acid do to your muscles?

Makes them feel sore and tired

What are autotrophs?

Organisms that make their own food

What are the products of cellular respiration?

ATP, CO2, H2O

Where do the light reactions of photosynthesis occur?

Thylakoid Membrane

What is the first step in cellular respiration called?

Glycolysis

Where do the light reactions of photosynthesis occur inside the cell?

Chloroplast

What is mitosis?

The division of the nucleus

What is cytokinesis?

The cytoplasm splits

List the order of the eukaryotic cell cycle.

G1, S, G2, M

Why is cell division in eukaryotes a complex process?

Because it contains several intricate organelles including the nucleus

Define cancer.

A disease in which cells grow out of control forming abnormal masses

What does mitosis ensure for new cells?

(Answer not provided in the notes)

List the steps in order of mitosis.

Prophase, Metaphase, Anaphase, Telophase

What type of cell division reduces the number of chromosomes in half?

Meiosis

In which stage of meiosis do chromatids appear?

Prophase

How many chromosomes do human gametes have?

23

Define independent assortment.

When cells divide during meiosis, homologous chromosomes are randomly distributed to daughter cells, and different chromosomes segregate independently of each other

Define binary fission.

Parent cells split into two identical daughter cells

What type of cell and what chromosome number does human fertilization produce?

Diploid Zygote (46 Chromosomes)

Meiosis begins with one cell and ends with how many?

4

What is genetics the science of?

Hereditary

What is the genotype of Aa?

Heterozygous Dominant

List Mendel's two laws of genetics.

Law of Segregation, Law of Assortment

Define phenotype.

The physical characteristics of an offspring

What is the genotype of Ab?

Heterozygous

What potential genotypes would result from an AABB x aabb cross?

100% AaBb

What expected genotypes would result from a Bb x Bb cross?

BB, Bb, Bb

Define codominance.

When both alleles in a gene pair are fully expressed

How many possible genotypes can ABO alleles have?

Six

What is the central dogma of molecular biology?

From DNA to RNA to Proteins

What structure does a double helix most closely resemble?

DNA

How does RNA differ from DNA?

RNA is small, has one nucleotide chain, contains Uracil, and has Ribose sugar; DNA is large, has two nucleotide chains, contains Thymine, and has Deoxyribose.

What is the function of mRNA?

Copies the genetic instructions from DNA to the nucleus and carries them to the cytoplasm.

Define transcription.

DNA -> mRNA

What are introns?

Sections of a gene that do not code for proteins

What are exons?

Sections of a gene that do code for proteins

How many codons comprise the genetic code?

64

List three things that are true about mutations.

Essential for evolution, a change in the sequence of DNA bases, have an effect on organelle most of the time

List three different mutations that can result in a genetic disorder.

Deletion, Inversion, Duplication, Translocation