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106 Cards in this Set
- Front
- Back
Life science
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the study of living things
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hypothesis
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an educated guess based on previous knowledge, a possiable answer to a question
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scientific method
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a series of steps scientists follow to find an answer to a question
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theory
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an explanation that ties together many hypotheses and observations
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area
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a measure of the size of a surface or a region
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volume
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the amount of space an object takes up
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mass
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the amount of matter in an object
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density
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the amount of matter in a given amount of space
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scientific method steps
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1) ask a question 2) form a hypothesis 3) test the hypothesis 4) analyze the results 5) draw conclusion 6) communicate your results
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why is the metric system useful?
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scientist use the metric system, which makes it easy to communicate their results with other scientists
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metric unit and abbreviation for mass
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gram-g
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metric unit and abbreviation for volume
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liter-L
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metric unit and abbreviation for length
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meter-m
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what device would you use to measure Mass?
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triple beam balance
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what device would you use to measure Volume
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graduated cylinder
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what device would you use to measure length
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meter stick
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cell
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a membrane covered structure that can preform all life processes
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stimulus
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a change in an organisms environment that causes a change in the behavior of the organism
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sexual reproduction
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when 2 parents produce offspring that share characteristics of both parents
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asexual reproduction
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when 1 parent produces an identical copy of itself
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heredity
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the passing of traits from one generation to the next
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protein
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a molecule of life that is made of amino acids and forms many structures like hair, fingernails, spiderwebs etc
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lipid
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a molecule of life that stores energy like fats and oils
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phospholipids
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a type of lipid that forms the cell membrane
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carbohydrate
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a molecule of like that stores energy like sugars and starches
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ATP
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a molecule of life that provides energy for the cell
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nucleic acid
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a molecule of life that contains genetic information like DNA and RNA
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6 characteristics of all living things
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1) can reproduce 2) use energy 3) have cells 4) have DNA 5) sense and respond to change 6) grow and develop
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How does sexual reproduction differ from asexual reproduction?
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sexual needs 2 parents and asexual needs only 1 parent.
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what are the 4 necessities of living things?
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food, water, air, and a place to live
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what are the 5 molecules of life?
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1) proteins form structures like hair, fingernails and spider webs and they help chemical reactions to occur quickly 2) lipids – store energy for the organism 3) carbohydrates store energy for the organism 4) ATP provides energy for the cell 5) nucleic acids contain the genetic information
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cell membrane
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the structure that surrounds and encloses the cell and is made of phospholipids
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cytoplasm
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the gel like substance found in the cell that holds the organelle in place
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organelle
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structures that preform specific functions within the cell
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nucleus
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the large organelle in the cell that contains the DNA
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prokaryote
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organisms whose cells don't have a nucleus
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eukaryote
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organisms whose cells have a nucleus
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unicellular
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organisms that are made of only one cell
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multicellular
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organisms that are made of more than one cell
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cell wall
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a rigid structure found outside the cell membrane that provides support for the cell, found in plants cells, bacteria cells, and fungus cells
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ribosome
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the organelle that makes proteins
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mitochondrion
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the organelle that provides the cell with energy in the form of ATP through the process of cellular respiration
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chloroplast
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the organelle in plant cells uses sunlight to make food through the process of photosynthesis
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tissue
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a group of calls working together to preform a specific job
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organ
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a group of tissues working together to preform a specific job
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organ system
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a group of organs working together to preform a specific job
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organism
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a living thing
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what's the difference of prokaryotes and eukaryotes?
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eukaryotes have a nucleus and other specialized organelles. Prokaryotes do NOT have a nucleus or other specialized organelles
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whats the relationship between cells, tissue, organs, organ system, and organisms
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multicellular organisms are made of organ systems. Organ systems are made of organ systems. organ systems are made of tissue. tissues are made of cells
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diffusion
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the movement of particles from areas of high concentration to low concentration
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osmosis
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the diffusion of water across a semi-permeable membrane
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semi-permeable membrane
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a barrier that allows some materials to pass through but not everything
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passive transport
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the diffusion of particles through a protein doorway in the cell membrane
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active tranport
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the movement of particles through a protein doorway in the cell membrane; particles move from LOW concentration to HIGH concentration and this process REQUIRES energy
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Protein doorways
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protein molecules in the cell membrane that allow particles to pass through
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Endocytosis
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the process in which cells engulf large particles into the cell
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Photosynthesis
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the process in which plants use sunlight to convert water and carbon dioxide into food (glucose) and oxygen
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Cellular respiration
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the process in which cells use oxygen to break down food in order to produce energy in the form of ATP
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Chromosomes
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a structure in the nucleus that is made of DNA and protein
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Mitosis
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the process in which a cell copies itself; this process produces new identical cells
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Cytokinesis
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after mitosis, the final step in which the cell divides in half
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What's the relationship between diffusion and osmosis
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Osmosis is a type of diffusion in which the particle that moves across the cell membrane is water. In both processes, the particles move from areas of high concentration to areas of low concentration and they do NOT require energy.
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There are six ways that cells move particles into and out of the cell
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diffusion, osmosis, passive transport, active
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Describe photosynthesis and cellular respiration.
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Photosynthesis is the process in which plants use sunlight to convert water and carbon dioxide into food (glucose) and oxygen. Cellular respiration is the process in which cells use oxygen to break down food in order to produce energy for the cells in the form of ATP.
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Where does each process occur?
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Photosynthesis occurs in the chloroplast and cellular respiration occurs in the mitochondrion.
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What is produced during each process?
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Photosynthesis produces oxygen and glucose. Cellular respiration produces carbon dioxide, water and energy in the form of ATP.
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What is the chemical equation for each process?
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Photosynthesis: CO2 + H2O + sunlight → C6H12O6 + O2 Cellular Respiration: C6H12O6 + O2 → CO2 + H2O + ATP
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How is cellular respiration related to breathing?
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Breathing takes in the oxygen that is needed for cellular respiration and breathing gets rid of the carbon dioxide that is produced during cellular respiration.
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Explain how cells produce more cells.
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1) the chromosomes copy themselves 2) the nucleus breaks down 3) the chromosomes line up in the middle of the cell 4) each copy of the chromosomes move to opposite sides of the cell 5) a nucleus forms around each new set of chromosomes 6) the cell splits in half
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What is the purpose of mitosis?
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The purpose of mitosis is to produce more identical cells.
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Heredity
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the passing of traits from one generation to the next
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Dominant trait
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the trait that overpowers the recessive trait
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Recessive trait
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the trait that gets overpowered by the dominant trait
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Gene
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one set of instructions for an inherited trait
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Allele –
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one of the different form of the same gene
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Phenotype –
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an organisms physical appearance
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Genotype
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the specific combination of genes for one trait
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Probability –
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the likelihood that a possible future event will occur
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Homozygous –
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when the genotype has two of the same alleles
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Heterozygous –
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when the genotype has two different alleles
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Meiosis
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the process of producing sex cells which have half the number of chromosome as the original cell
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Sex chromosome –
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the pair of chromosomes that determine the sex of the offspring
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Explain how genes and alleles are related to genotypes and phenotypes.
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A gene is a set of instructions for the same trait. Different forms of the same gene are called alleles
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Explain the difference between mitosis and meiosis. Mitosis produces cells that are identical to the original cell, while meiosis produces sex cells with half the number of chromosomes as the original cell.
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Mitosis produces cells that are identical to the original cell, while meiosis produces sex cells with half the number of chromosomes as the original cell.
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What is the purpose of meiosis?
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To produce sex cells with half the number of chromosomes as the original cells.
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DNA –
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a molecule that contains the genetic information of an organism
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Nucleotide –
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a subunit of DNA that is made of a sugar, phosphate and a base
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Double helix –
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the shape of a DNA molecule
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DNA replication – the process in which DNA copies itself
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the process in which DNA copies itself
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RNA –
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a nucleic acid that helps DNA to make proteins
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Ribosome –
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the organelle that makes proteins
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Mutation –
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a change in the sequence of bases in a DNA chain
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Describe the basic structure of DNA.
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The DNA molecule has the shape of a twisted ladder. Alternating sugar and phosphate molecules form the sides of the ladder and nucleotide bases form the rungs of the ladder. The molecule is made of subunits called nucleotides which are made of sugar, phosphate and base.
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What are the four possible bases in a nucleotide of DNA?
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Adenine, thymine, cytosine, guanine
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Which bases form complementary pairs?
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Adenine and thymine form a pair and cytosine and guanine form a pair.
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1) What are the two important functions DNA must be able to perform?
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DNA must be able to copy itself and provide instructions for making proteins.
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1) Describe how DNA copies itself.
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The DNA molecule untwists and unzips. Then, free floating nucleotide bases attach themselves to the exposed nucleotide bases along each side of the DNA molecule forming a new DNA molecule.
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1) Explain the relationship between DNA, genes and proteins.
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Genes are located on the DNA molecule. There are several genes on each DNA molecule. Each gene provides instructions for making a specific protein.
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1) Outline the basic steps in making a protein.
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The DNA molecule untwists and unzips. Then, free floating nucleotide bases attach themselves to the exposed nucleotide bases along one side of the DNA molecule forming a mRNA molecule. The mRNA molecule separates from the DNA molecule and is transported out of the nucleus. The mRNA molecule attaches to a ribosome and tRNA molecules bring amino acids to the ribosome. The ribosome attaches the amino acids to each other forming a protein.
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1) Are DNA mutations good or bad? Why?
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Sometimes DNA mutations are good which allows evolution to occur. Sometimes DNA mutations are bad and can cause health problems in organisms.
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Species –
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a group of organisms that are closely related and can mate to produce fertile offspring.
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Evolution –
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the process in which populations gradually change over time
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Adaptation –
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a characteristic that that improves an individual’s ability to survive and reproduce in a particular environment
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Selective breeding –
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The human practice of breeding animals or plants that have certain desired traits
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Natural selection –
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the process by which individuals that are better adapted to their environment survive and reproduce more successfully than less well adapted individuals
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How does evolution happen?
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1) Evolution happens through natural selection. Here are the steps of natural selection: 1) there is an overproduction of offspring by members of a species 2) every individual inherits its own combination of traits 3) The members of a species struggle to survive 4) those individuals that are best adapted to the environment survive to reproduce and pass their traits on to their offspring.
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