Biology Flashcards
Dependent Variable
Observed variable that may or may not change in response to the independent variable.
Independent Variable
Factor in a controlled experiment that is intentionally or deliberately changed.
Control Group
Exposed to the identical conditions of the experimental group with the exception of the independent variable.
Hypothesis
Scientific explanation for set of observations that can be tested in a way that support or reject it.
Controlled Experiment
Testing a hypothesis by tracking various factors that can change (variables). Only one variable should be intentionally changed while others remain constant.
Asexual Reproduction
A single organism produces offsprings that are genetically similar to itself.
Sexual Reproduction
Cells from two parents unite to form the first cell of a new organism.
Metabolism
Combination of chemical reactions through which an organism builds up or breaks down materials.
Homeostasis
A relatively stable internal environment.
Ionic Bond
Formed when two or more electrons are transferred from one atom to another.
Covalent Bond
The bond formed when atoms share electrons.
Ions
Atoms with a positive or negative charge.
Isotope
Atoms of the same element that differ in the number of neutrons.
Element
A chemically pure substance with only one type of atom.
Electron
Negatively charged atomic particles; are in constant motion around the nucleus.
Neutron
Atomic particles with no charge.
Proton
Positively charged atomic particles.
Molecule
Smallest unit of most compounds.
Monomer
Small chemical unit that makes up a polymer.
Polymer
Molecules composed of many monomers; makes up macromolecules.
Carbohydrate
Compounds made of carbon, hydrogen, and oxygen atoms- usually in a ratio of 1:2:1.
What is the main source of energy for living things?
Carbohydrates
Monosaccharide
Single sugar molecules.
Lipid
Mostly made of carbon and hydrogen atoms. (Fats, oils, waxes)
Nucleic Acid
Macromolecules containing hydrogen, carbon, oxygen, phosphorus.
Nucleotide
Consists of a 5-carbon sugar, phosphate group, and a nitrogen base.
Protein
Macromolecules that contain nitrogen as well as carbon, hydrogen, and oxygen.
Amino Acid
Compounds with an amino group on one end and a carboxyl group on the other end.
Reactant
Elements or compounds that enter into a chemical reaction; input.
Products
Elements or compounds produced Ina chemical reaction; outcome.
Catalyst
Substance that speeds the reaction process.
Enzyme
Biological catalyst
Activation Energy
The energy that is needed to get a reaction started.
Hydrogen Bond
The attraction between a hydrogen atom with a partial positive charge and an atom with a partial negative charge.
Adhesion
An attraction between molecules of different substances.
Cohesion
Attraction between molecules of the same substance.
Solute
Substance that is dissolved in a solution.
Solvent
Substance in which another substance is dissolved in a solution.
Solution
A type of mixture where all components are evenly distributed.
Suspension
Mixtures of water and non-dissolved materials.
Buffer
Weak acids or bases that can react with strong acids or bases to prevent sudden, sharp changes in pH.
Acid
PH of less than seven; contains higher concentration of hydrogen atom than water.
Base
PH greater than seven; contains higher concentration of hydroxide ions.
pH Scale
Measurement system developed to indicate the concentration of hydrogen ions in a solution.
Why do cells divide?
Cell division reduces information overload and material exchange issues.
What does the rate at which materials are exchanged through the cell membrane depend on?
The surface area.
What does the rate at which food and oxygen are used and waste is produced depend on?
The volume.
True or False: Larger cells have a smaller surface area to volume ratio compared to smaller cells.
True
What happens to the surface area to volume ratio as the cell grows larger?
The surface area to volume ratio gets smaller.
When do spindle fibers attach to centromeres?
Metaphase
When does the nuclear membrane dissolve?
Prophase
When are centrioles at opposite ends of the cells?
Metaphase
When do spindle fibers begin to form?
Prophase
When do centrioles begin to separate?
Prophase
When are sister chromatids pulled apart and separate?
Anaphase
When do chromosome line up in the center of the cell?
Metaphase
When do spindle fibers disappear?
Telophase
When do spindle fibers shorten bringing chromatids to opposite ends of a cell?
Anaphase
When do chromatids condense forming chromosomes and become visible?
Prophase
When does the nuclear membrane form around the sister chromatids?
Telophase
This is when the cell takes is nutrients and eliminates wastes through the cell membrane.
Exchange of materials.
This solves the information overload and material exchange problems.
Cell division.
This type of reproduction…
- Produces genetically identical offspring
- Occurs in many single-celled organisms
Asexual Reproduction
This type of reproduction…
- Produces organisms with genetic information from both parents.
- Occurs in most animals and plants
Sexual Reproduction
True or False: As a cell’s size increases, its amount of DNA also increases.
True
True or False: The amount of activity in a cell is related to its volume.
True
True or False: The smaller the cell, the smaller its ratio of surface area to volume.
False
Packages of DNA are called ____.
Chromosomes
This is the series of events in the growth and division of a cell.
The cell cycle
The first three stages of mitosis (the G1 phase, S phase, and G2 phase) are referred to as____.
Interphase
What happens in the G1 phase of mitosis?
The cell grows
What happens in the S phase of mitosis?
DNA is replicated
What happens in the G2 phase of mitosis?
The cell produces organelles and materials for for division.
In which phase does the cell divide into two stages-mitosis and cytokinesis?
In the M-phase
In this phase of M-stage, the nucleus divides.
Mitosis
In this stage of mitosis, the cytoplasm divides.
Cytokinesis
Name the stage of mitosis:
A cell’s genetic material condenses, a spindle starts to form, and the nuclear envelope breaks down.
Prophase
Name the stage of mitosis:
The duplicated chromosomes line up in the middle of the cell and spindle fibers connect to the centromeres.
Metaphase
Name the stage of mitosis:
Sister chromatids separate and move towards the centrioles.
Anaphase
Name the stage of mitosis:
The chromosomes begin to unwind and a nuclear envelope reforms.
Telophase
Explain cytokinesis in animal cells.
The cell membrane draws in and pinches off.
Explain cytokinesis in plant cells.
A cell plate forms, followed by a new membrane, and finally a new cell wall forms.
These are proteins that regulate the timing of the cell cycle in eukaryotic cells.
Cyclins
(Internal/External) regulators allow the cell cycle to proceed when certain events have occurred within a cell.
Internal
(Internal/External) regulators called growth factors stimulate the cell cycle. Other regulators of this type cause the cell cycle to slow down or stop.
External
This is a programmed cell death that plays a key role in the development of tissues and organs.
Apoptosis
This is disorder in which cells divid uncontrollably, forming a mass of cells called a tumor.
Cancer
Give at least one treatment for cancer.
One of these choices:
- Removal of cancerous tumors
- Radiation
- Chemotherapy
True or False: Cells tend to continue dividing when they come in contact with other cells.
False
In what type of cell does the cell cycle occur?
a. ) Prokaryotes
b. ) Eukaryotes
b.) Eukaryotes
The is scientific study of heredity.
Genetics
Why did Gregor Mendel choose peas to work with?
At least one of these choices:
- Easy to work with
- There was a wide variety of traits
- Common and easily accessible
Gregor Mendel took the pollen off of one flower and transferred it to the female stigma of another flower.
What is it called?
Cross-pollination
This is a specific characteristic that varies from one individual to another.
Trait
What is does the P generation stand for? What is it?
Parental; the first generation studied.
What does the F1 generation mean?
First Filial Generation
What does the F2 generation mean?
Second Filial Generation
This is the offspring of crosses between parents with different traits.
Hybrid
Give at least one reason why Gregor Mendel was unique.
At least one of these choices:
- he did thousands of trials
- he studied more than one trait
- explained results using probability
The type of trait that appeared in the F1 generation every time.
Dominant Trait
The hidden trait, seemed to disappear in the F1 generation.
Recessive
These are factors that determine traits.
Genes
Which principle or law of Mendel’s said this?
Some alleles are dominant and others are recessive?
Principle of Dominance
What is Mendel’s Law of Segregation?
When a gamete forms, two alleles must separate.
What is the mathematical chance that something will occur called (also: the likely hood that an event will occur)?
Probability
Which principle is used to predict the outcome of genetic crosses?
Principles of Probability
What is used to predict outcomes of crosses?
A punnett square
What are organisms that have the same alleles for a trait called (e.g. AA or aa)
Homozygous
What are organisms that have different alleles for a trait called (e.g. Aa)
Heterozygous
What does phenotype mean?
Physical appearance of a trait
What does genotype mean?
The genetic make-up
What kind of cross looks at one particular trait?
Monohybrid
Which of these says that alleles assort independently during fertilization?
a. ) Monohybrid Cross
b. ) Independent Assortment
c. ) Dominance
b.) Independent Assortment
What is it called when neither allele is completely dominant of another?
Incomplete dominance
What is it called when there are more than 2 alleles for a specific gene?
Multiple Alleles
What is it called when traits are controlled by many different genes?
Polygenic traits
_____ is when both alleles in the heterozygous genotype are expressed (not a blending).
Codominance
True or False: Genes can be influenced by environmental factors.
True
Temperature, availability of food/nutrients, disease, and chemicals are all examples of _____.
Environmental factors
____chromosomes are chromosomes that contain the same same genes
Homologous
What is the symbol for diploid cells?
2n
What is the symbol for haploid cells?
n
Body cells are (diploid or haploid) cells.
Diploid
Gametes are (diploid or haploid) cells.
Haploid
If an organism’s diploid cells contain 46 chromosomes, how many chromosomes are in the haploid cells?
23