Name______

Per_____

PreAP Biology Spring EOS Review

Introduction to Biology

Distinguish among the following:

independent variable and dependent variable -The independent variable is one the scientist determines to change. It is not dependent on anything else. The dependent variable is being measured and depends on the value of the independent variable. Independent is on the x-axis; the dependent is on the y-axis.

control set-up and constant -The control setup you do nothing to. It is not altered from natural conditions. The constant is every factor that must remain the same to be sure that the independent variable is causing the resulting dependent variable.

Review laboratory safety rules. Be sure you can apply them to situations described for you. For example, what is the first rule in case of an accident? When do you have to wear goggles (be specific, don’t just say “always”)? If there is an accident, immediately tell the teacher. Wear goggles anytime you are working with chemicals, sharp objects, heat or anything that could potentially harm your eyes.

Draw and identify the function of the following pieces of laboratory equipment. If it is used for measuring identify what is being measured and the unit.

Ex) metric ruler - measures length in centimeters or provides a straight edge when creating scientific drawings

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Forceps- Picking up or moving very small items

Beaker-Hold, heat or mix chemicals.

Not for measuring.

Ehrlenmeyer flask-Hold, heat or mix chemicals. Not for measuring.

graduated cylinder-Measure liquids with accuracy. Not for heating.

balance (not a scale!)-For

measuring the MASS of an object with accuracy.

Thermometer-For measuring heat with accuracy, always in Celsius.

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Six hundred plants were divided into 6 groups of 100 each. Each group was placed in lights of different colors for 600 hours. Group I was kept in red light, Group II in yellow light, Group III in green light, Group IV in blue light, Group V in white light and Group VI in ultraviolet light. Every 60 hours the number of leaves on the plants were counted and the width of the leaf at its broadest point was measured.

4. Identify the components of the experiment.

Independent variable: _color of light______

Dependent variable: __leaf width_

Constants: _Type of plan, size of plant, soil, amount of water, time in light.___

Hypothesis:If plants are grown under various colors of light, then plants will grow best in light.

Describe a control set-up or control group: Plants in 5. Set up a graph. Label the X and Y axes. Title the graph. (You do not need to GRAPH anything, only set it up!)

Leaf Width of Plants Under Various Colors of Light for 600hrs.

Width of

Leaf (cm)

Hours Under Colors of Light

Microscopes

What can you NOT touch on the microscope once you have moved the 10X or 40X objective into place? ____The coarse focus knob. Why? Because you will break the slide or damage the lens.

Explain how to make a wet mount slide of cheek cells using a glass slide and coverslip. Scrape the inside of your cheek with the end of a flat toothpick. Add one drop of Methylene blue to slide. Smear the toothpick in the drop and immediately cover with a cloverslip, placed at a 45 degree angle.

If you increase the magnification, can you see more or less of a specimen? _Less_ Explain. There is more of the specimen in view and less of the surrounding areas. It’s like getting closer.

Review the parts of the microscope. Ocular lens (eyepiece), Revolving Nosepiece (houses objective lens), Objectives (4X, 10X and 40X), Stage (where slide is placed), Stage Clips (holds slide in place), Diaphragm (controls amount of light passing through the object), Coarse Adjustment Knob (used to focus under low power), Fine Adjustment Knob (Used to fine tune focus under any power).

Cells: Structure & Function

Draw and label the following cell structures, including their infrastructure:

chloroplast, mitochondria, nucleus

Distinguish among the following terms:

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active transport-Energy (ATP) required to move molecules from low to high concentration; up/against the concentration gradient. Ex. endo & exocytosis; Na+/K+ pump; H+ pump

Diffusion-Process by which molecules spread from areas of high concentration to low without requiring energy; down/with the concentration gradient; a type of passive transport

Endocytosis-Substances are moved INTO a cell by a vesicle that pinches off from the cell membrane; requires energy (ATP) so is a type of active transport

Exocytosis-Substances inside a vesicle are released OUT OF a cell as the vesicle fuses with the cell membrane. (requires energy = active transport)

facilitated diffusion-Moves substances down the concentration gradient w/o using cell’s energy, using channel/carrier proteins located in the membrane. (passive transport)

Osmosis-The diffusion of water molecules through a semi-permeable membrane without requiring energy. (passive transport)

passive transport- movement of molecules from high to low concentration without requiring energy. ex. Diffusion, facilitated diffusion and Osmosis.

Phagocytosis-A type of active transport/endocytosis when the nutrient particles are solid; (Cellular eating.)

Pinocytosis- A type of active transport/endocytosis when the nutrient particles are dissolved in a liquid; (cellular drinking.)

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Illustrate the terms hypotonic, hypertonic, and isotonic using the beakers and cells shown below. Explain what you would expect to happen if the cell membrane is semipermeable (selectively permeable).

HYPOTONIC HYPERTONIC ISOTONIC

Solvent = water; solute = dissolved particles

Isotonic-Concentration of solution outside the cell is the same as the concentration of the solution inside. Water is moving out and in at equal rates.

Hypertonic-There are more solute molecules in the solution outside the cell compared to the concentration inside the cell. Water will move out of the cell and the cell will shrink.

Hypotonic-There are less solute molecules outside the cell than inside the cell. Water will move into the cell and the cell will swell

Biochemistry

What inorganic molecule is required for most reactions involving large polymers such as proteins, nucleic acids, and polysaccharides? Water

What does organic mean? A molecule containing Carbon (except CO and CO2)

Review the terms hydrolysis and dehydration synthesis (use word parts). Which one of these produces water (so removes water)? Which one requires water as a reactant? Dehydration-Produces water(so removes water.) Hydrolysis-Requires water as a reactant.

Identify the monomer for the polymer:

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carbohydrate - Monosaccharides

nucleic acid - Nucleotides

starch – Glucose (monosaccharides)

protein –Amino Acids

DNA – Nucleotide= deoxyribose sugar + phosphate + Nitrogen base

Glycogen-Glucose(monosaccharide)

RNA – Nucleotide= ribose sugar + phosphate + Nitrogen base

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Draw and label a nucleotide. (sugar + phosphate + nitrogen base)

Note: Nitrogen bases only connect to sugar. Sugars and

phosphates alternate and make up the sides of DNA; nitrogen

bases connect in the middle by hydrogen bonds. A-T, G-C

DNA, RNA, and Protein Synthesis (Gene Expression)

Review the process of gene expression:

What are the two parts or processes involved in gene expression? Transcription;Translation

Where in the cell does each occur? Transcription(Nucleus,) Translation (cytoplasm @ ribosome)

What is the role of each molecule involved?

mRNA carries a message it got from DNA in the nucleus to a ribosome in the cytoplasm. tRNA brings the appropriate amino acid to the Ribosome(made of rRNA) that mRNA is coding for.

What is the product of each part of the process? The product of Transcription is mRNA. The Product of Translation is a newly formed protein (made from a chain of amino acids).

DNA replication – tell all you know! DNA replication takes place in the Nucleus of a cell. Helicase unwinds and unzips the double helix of DNA, by breaking the hydrogen bonds. DNA Polymerase brings free nucleotides to the DNA molecule that compliment, (A-T) (C-G), those on the unzipped strand. This occurs in the direction of the replication fork (5’ to 3’) and happens easily on the leading strand. Because the lagging strand is (3’-5’) it must add nucleotides in short (5’-3’) segments called Okasaki fragments. These fragments are joined together by ligase. The overall direction of growth is toward the replication fork. Two new molecules are completed and must to wound back up. Both molecules are identical, each having one parent and one new strand.

List the 5 nitrogenous bases found in nucleic acids. Identify the one unique to RNA by circling its name. Show how the bases pair. Which ones are pyrimidines and which are purines?

Adenine and Guanine are purines

Thymine, cytosine and (uracil—only in RNA) are pyrmidines

(A-T) and (G-C) in DNA (A-U) and (G-C) in RNA

Create a table comparing DNA and RNA.

DNA RNA

Sugar deoxyribose ribose

Nitrogen Bases A, T, C, G A, Uracil, C, G

Shape double helix single strand

Biotechnology

What is a genetically modified organism? When a genome of a living cell is altered for medical or industrial use. How could one be created? It may involve building recombinant DNA made from two or more different organisms. DNA fragments from a vector of interest may be added to another organisms DNA and are helped to bond with an enzyme called DNA ligase.

What is a clone? An organism that is produced by asexual reproduction and that is genetically identical to its parent.

How can you determine if two people are related using a DNA fingerprint? Each individual has a unique pattern of banding. The banding patterns from two individuals can be compared to establish whether or not they are related. A similar pattern will be noted if they are related.

Does a “match” to crime scene DNA mean the person is guilty? No. Explain. DNA can be found in bone, semen, blood or hair. Just because a person’s DNA is present at the scene of the crime doesn’t necessarily mean they committed the crime. They may have just been present at the scene at some point.

Cell Cycle

Below is a somatic cell in interphase about to undergo mitosis. First, draw an arrow and label it with the name of the process that must occur before mitosis, then draw and label a cell in each stage of mitosis. Be sure you show the correct number of chromosomes at each stage as well as the correct number of cells at the end of the process.

Interphase (G1, S, G2) Prophase Metaphase Anaphase Telophase Cytokinesis

Protein Synthesis (Gene Expression) occurs in the G1 phase of interphase)

DNA Replication (occurs in S phase of Interphase)

What kind of cells are produced by mitosis? Circle the words that apply (answers in BOLD* below).

asexual*

diploid* (chromosomes in pairs=2 of each chromosome; humans 23 pair or 46 total)

gamete (sex cells, like eggs & sperm)

haploid (1 of each chromosome; humans is 23)

identical*

sexual

somatic*(body cells, like skin cells)

unique

What are the purposes for mitosis? It is the process of nuclear division that occurs in somatic cells. It is an ordered set of events of cell growth and division resulting in two daughter cells which then start the process again. (Growth, Repair, Reproduction)

When control of the cell cycle is lost, what results? A tumor or cancer

Which words in the list in question 2 apply to meiosis? Gamete, haploid, sexual and unique.

What is the purpose of meiosis? A form of cell division that halves the number of chromosomes forming specialized reproductive cells such as gametes; produce gametes/sex cells = eggs or sperm

What are the sources of variation found in the gametes after meiosis? (DNA mutation is not what we’re talking about!) Independent Assortment, Crossing-over, and Random Fertilization.

If a leaf cell of a poplar tree has 36 chromosomes, how many chromosomes would you expect to find in a sperm cell in a grain of pollen? 18

If a sea urchin has 14 chromosomes in an ovum, how many will it have in an epidermal cell? 28

Genetics

If traits are passed down from parent to offspring through gametes formed during meiosis, how are mutations passed down? From parents to offspring through gametes; mutation MUST occur in the DNA of gametes (egg or sperm) to be passed to offspring.

Differentiate between the following terms.

dominant and recessive-When two different alleles occur together, one of them may be completely expressed, while the other has no observable effect on the organism. The expressed form of the character is dominant (R) while the character that was not expressed is described as recessive (r)

homozygous and heterozygous-If two of the same alleles of a particular gene are present in an individual they are said to be homozygous (RR or rr) for that character. If the two alleles of a particular gene are different, the individual is heterozygous (Rr).

genotype and phenotype-The set of alleles that an individual has for a character is called its genotype (RR, Rr, rr). The physical appearance of a character is called its phenotype (red or white).

incomplete dominance and codominance- In incomplete dominance an individual displays a phenotype that is intermediate between the two parent (RR red, Rr pink, rr white). In codominance two dominant alleles are expressed at the same time. In this case, both forms of the character are displayed (RR red, Rr red & white, rr white).

autosomal and sex-linked inheritance-If a gene is autosomal, it will appear in both sexes equally. An autosome is a chromosome other than an X or Y sex chromosome. If a trait is sex-linked, its effects are usually only seen in males and the gene is located only on the X or Y chromosome; in this class we only studied X-linked sex-linked traits (only on the X chromosome, therefore females can be carriers, males cannot)

Review monohybrid and dihybrid crosses by making up 2 to 3 problems of each and working them out in the space provided. Be sure you include genotypic and phenotypic ratios in the monohybrid crosses and phenotypic ratios in the dihybrid.

Rr x Rr (R = red, r= white)

R r

RR / Rr
Rr / rr

Genotypic Ratio: 1:2:1 (RR, Rr, rr)

Phenotypic Ratio: 3:1 (red , white)

Y = yellow, y = green; R = round, r = wrinkled

YYRR / YYRr / YyRR / YyRr
YYRr / YYrr / YyRr / Yyrr
YyRR / YyRr / yyRR / yyRr
YyRr / Yyrr / yyRr / yyrr

Phenotypic Ratio:

9:3:3:1

Yellow, round =9

Yellow, wrinkled = 3