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61 Cards in this Set
- Front
- Back
What is a Nucleus? |
Organelle that controls all activities of the cell and is surrounded by the nucleus membrane that protects the contents of the nucleus |
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What is a Nucleolus? |
Membrane-free organelle that floats inside teh nucleus and makes ribosomes |
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What does the nucleus contain? |
Master set of instructions: what each cell will become, how each cell will function, when each cell will grow and divide, when each cell will die. |
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What are the instructions in the nucleus,which are carried in two-long stranded molecules, called? |
DNA |
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What is the DNA ladder made up of? |
The sides are made up of sugar and phosphate. The steps are made up of 4 nitrogen bases. AG,GC |
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What contains DNA and proteins |
Chromatin |
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What is it called when the cell is ready to divide and the chromatin turns into a compact, X-shaped structure |
It turns into a Chromosome |
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Small segments of DNA that are called 'blank' that are located at specific places on a Chromsome |
Genes |
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What do Genes do? |
They store information needed to produce different proteins used in the cells determined by the arrangement of bases |
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What are Enzymes? |
Specialized proteins that speed up chemical reactions within each celll |
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What is the name of other proteins that act as chemical messengers? |
Hormones |
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What are the first 4 steps to make proteins? |
1. Nucleus receives chemical signal to make specific protein 2. DNA message is copied into the RNA 3. RNA leaves through Nuclear Pores 4. RNA message is delivered to Ribosome, which makes protein |
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What are the next steps to making proteins? |
5. Protein enters ER
6. Vesticle forms off end of ER - go to Golgi body 7. Golgi repackage protein 8. Vesticle forms then carries protein to cell membrane 9. Vesticle attaches to cell membrane, protein contents are released |
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What are three types of gene mutation? |
Deletion (one base is missint) Addition (an extra base is added) Substitution (one base is substituted for another) |
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Errors in the sequence of DNA bases may produce proteins that can be beneficial, harmful, or neutral to the organism |
Mutation |
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What is a positive mutation? An example? |
Produce protein that is beneficial to an organism. HIV resistance |
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Reduce probability that organism will produce offspring of will survive in their environment. Ex. substituting base A and T on a certain gene causes the Hemoglobin protein to be shaped differently causing "sickle cell amemia" Or, Cystic fibrosis What is this? |
Negative mutation |
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True or false Neutral mutation is when substituting one base for another in the DNA sequence does not change an organism and proteins will still functions. Ex. White coat colour of the 'Spirit Bear" |
True |
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What are Mutagens? Examples? |
Substances that can cause mutations in DNA by disrupting the instructions stored in genes. Causes genes to be misread of copied incorrectly. Ex. Cigarette smoke, radiation, pollutants, household chemicals |
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What is gene therapy? |
Replace mutated gene with a healthy copy of the gene. Very risky. Healthy gene must attach itself to a chromosome within the nuclei. Can affect an individual immune system. |
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What are three things cells can do? |
Grow Divide Die |
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What are the three stages of the Cell Cycle? |
Interphase: cells carry out functions and prepare for reproduction Mitosis: duplicated contents of the nucleus are divided into two equal parts Cytokinesis: separates into two daughter cells |
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What happens in Interphase? |
Cells grow and DNA replicates. |
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What happens in Prophase, Mitosis? |
X-shaped chromosomes are visible and spindle fibres begin to form and stretch across the cell from centrioles. Chromosomes attach to spindle fibres |
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What happens in Metaphase, Mitosis? |
Spindle fibres pull chromosomes into a single line a the 'equator' |
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What happens in Anaphase, Mitosis? |
Spindle fibres contract and shorten, pulling the centromere apart. Sister chromatids separate and move to opposite poles |
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What happens in Telephase, Mitosis? |
One complete set of chromosomes is at each pole of the cell. Nucleolus appears. Nuclear membrane forms. Cell is ready to divide |
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What happens in Cytokinesis? |
Separates the two nuclei into two daughter cells. New cells are identical to original parent cell |
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What are the checkpoints in the Cell Cycle? |
Special proteins monitor cell activity and send info to nucleus Nucleus instructs the cell whether or not to divide |
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Cells will not divide if...? |
Not enough nutrients DNA has not been replicated DNA is damaged |
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What are cancerous cells? |
Result in out-of-control cell cycle Uncontrolled cell division |
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What is Asexual Reproduction? |
One parent is required to produce offspring Offspring looks identical to parent |
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What is Binary Fission? Example? |
Genetic material and divides into two equal parts. Only method for some bacteria. Ex. Marine algae |
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What is Budding? Example? |
Undergo repeated mitosis. Develops a 'bud' that may detach from parent and become a new individual. Ex. Hydra, sponges, yeast cells |
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What is Fragmentation? Examples? |
Occurs when and organism breaks apart. Each fragment develops into a clone of its parent. Ex. Sea stars |
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What is Vegetative Reproduction? Examples? |
When special cells divide repeatedly tor form structures. Eventually develop into a plant identical to the parent. Disadvantage - grow close, competition for soil |
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What is Spore Formation? Examples? |
Spore is a reproductive cell that grows into a new individual by mitosis. Rely on water and wind to carry them away from parent where individual will grow if they right conditions are met Ex. Fungi, moss |
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What is Assisted plant reproduction? Examples? |
Cutting: removes section of stem (household plants) Grafting: Scions are attached to the rooted stock of a similar plant. Plant buds can be inserted into slit (apple trees) |
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What is Cloning? |
Less complex: animals can clone themselves by asexual methods More complex: Multicellular animals lose their cloning ability as cells become specialized |
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What is Reproductive cloning? |
Adult DNA cloning. To produce a genetic duplicate of an organism with desirable qualities |
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What is a Diploid? |
body cells that have two sets of chromosomes humans have 46 |
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What is the haploid number in humans? |
23 |
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What are haploid chromosomes carried in? |
Gamets - specialized cells necessary for reproduction |
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What happens during Fertilization? |
Egg cell is penetrated by a sperm cell and haploid genetic info from the male and female gamets combines |
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When a Sperm enters an Egg, the two haploid cells become one diploid cell. What is it called? |
A zygote |
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What does the Zygote undergo to develop into an embryo? |
Mitosis |
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What happens during meiosis? |
process that produces gametes with half the number of chromosomes as body cells- otherwise fertilization would produce offspring with 2x the original number of chromosomes. DNA replicates. Two complete cells after Meiosis 1&2 |
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What happens in Meiosis 1? |
A pair of matching chromosomes line up at the equator. Pair separates and moves to opposite poles of the cell. Two daughter cells result from this. (crossing over, independent assortment, gamete formation) |
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What happens in Meiosis 2? |
Chromatids of each chromosomes are pulled to opposite poles. Each daughter cell inherits one chromatid from each chromosome. Result in 4 haploid cells, each with half the number of chromosomes. |
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What is mating? |
Where gametes arrive in the same place at the same time. |
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What type of fertilization happens outside the bodies of the parents? when male and females release gametes into water through spawning. Ex. Sea urchins |
External Fertilization |
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What are advantages for External fertilization? |
Advantages: little energy required to find a mate, ability to reproduce lagre number of offspring, not much competition for food, good chance of genetic variation. Disadvantages: not many gametes survive, many gametes don't meet, Zygotes and embryos are unprotected, parents don't care for offspring |
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What is the type of fertilization where the sperm cells are deposited inside the female's body where they meet the egg cell? |
Internal Fetilization |
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What are advantages for Internal fertilization? |
Advantages: more offspring can survive Disadvantages: more energy to find a mate, produce fewer zygotes as opposed to external |
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What conditions need to be met in order for cell division? |
Enough nutrients, proper temperature for proteins and enzymes to function, enough moisture, protection |
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What is pollination? |
Transfer of male gametes in structure called pollen from the male reproductive part of a plant to the female reproductive part |
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What is the Embryonic Development? |
Early development of an organism. Takes place during the first two months after fertilization for humans. |
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What is a morula? |
Fertilized egg begins mitosis, rapidly dividing to form a ball of cells |
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When the Morula hollows out, what is it called? |
A bastula |
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When a blastula is organize into layer, what is it called? |
A gastrula |
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What are the layers of the Gastrula? |
Ectoderm- skin and nervous system Mesoderm- kidneys, skeleton, blood vessels, muscles and reproductive organs Endoderm- liver, lungs, digestive lining for the digestive system |