Biology Answers

Lesson 6
  1. It responds to the environment. It grows and develops and dies. It produces offspring. It maintains homeostasis. It has complex chemistry, and it consists of cells. It obtains and uses energy.
  2. The four unifying principles of biology are cell theory, gene theory, homeostasis and evolution.
  3. The outline levels of organization of a complex, multicellular organism such as a mouse, starting with the cell is: The Cell – then Tissue – then Organ – then Organ System – to Finally Organism (the mouse)
  4. Homeostasis is the process of maintaining a stable internal environment. Breathing is an example of homeostasis.
Lesson 7
Creation Story
  1. 3500
  2. 40
  3. 6th
  4. Man was created in God’s image.
  5. It is good.
  6. Every tree except the tree of the knowledge of good and evil.
  7. Yes. (Pet peeve–The picture of the angel.  We are never told in the Bible that angels have wings.)
  8. Satan fell because of his pride.
Lesson 9
  1. The sugar was in the water. When the water was heated, more sugar was able to be dissolved. As the water cooled, it couldn’t hold the sugar anymore, and it reappeared, coming out of the water. The sugar is abiotic. It was not reproducing and dying. You are only seeing the sugar that was added into the water in the first place.
Lesson 10
Characters Of Living Questions
  1. Biology is the study of living things.
  2. Cells are the smallest unit of life capable of carrying out all the functions of living things. The small structures within cells are called organelles.
  3. A, B, D
  4. Two types of reproduction are sexually and asexually.
  5. An organism needs a constant supply of energy and materials to carry out its essential processes to stay alive.
  6. Metabolism is the chemical processes that occur within a living organism in order to maintain life.
  7. Homeostasis is the process of maintaining a stable internal environment.
Lesson 12
Science and the Natural World
3.  A hypothesis is a possible answer to a scientific question, but it isn’t just any answer.    Characteristics of a hypothesis are:
  1. must be based on scientific knowledge, and it must be logical, and
  2. must be falsifiable.
5. A natural study shows what actually occurs in nature. Therefore, it may provide a truer picture of what happens in the real world than an experiment does.
  1. Independent/Manipulating Variable:amount of exercise a person gets
    Dependent/Responding Variable: the time it takes to run a kilometer
  2. Independent/Manipulating Variable: The higher temperature of water Dependent/Responding Variable: the faster the egg will cook
  3. Independent/Manipulating Variable: if keeping the lights on for different amounts of time each day
    Dependent/Responding Variable: the number of eggs chickens laid
  4. Independent/Manipulating Variable: at different depths
    Dependent/Responding Variable: the temperature of water in a lake varied
  5. Independent/Manipulating Variable: is watered weekly than grass that is not watered
    Dependent/Responding Variable if grass will grow taller

Lesson 13

  1.  A hypothesis is a possible explanation for a set of observations or an answer to a scientific problem that can be tested.
  2. The independent (manipulated) variable is the variable that is deliberately changed.
  3. Experiments should have only one variable is being tested. When all other variables are unchanged/controlled, we now the response (dependent/responding variable) is due to the one variable being changed.  A controlled experiment will have an experimental group and a control group. The experimental group is the manipulated group to which the independent variable is applied. The control group is exposed to all the same conditions as the experimental group EXCEPT for the independent variable.  This also supports that the response is due to the independent variable change.
  4. The dependent (responding) variable is the variable that is observed and that changes in response to the manipulated variable.
  5. This may vary some.  You will need to determine if your experiment would adequately test the effect of water temperature on a fish’s breathing rate.
    1. Materials might include a fish bowl with water and a fish, a heat lamp, a thermometer, a stopwatch
    2. Procedure:
      1. Take temperature of water in fishbowl (without heat lamp applied).
      2. Record number of breaths/gill movements within a 30 sec-1 min time frame.
      3. Apply heat lamp to raise temperature.
      4. Record number of breaths/gill movements within same time intervals at higher temperature.
    3. Manipulated variable would be water temperature.
    4. Control would be the same fish.
    5. Dependent variable – breaths/gill movements of the fish
  6. Petrozip vs Flashfuel
    1. Answers may vary.  My example is “A car using Petrozip will get better fuel mileage than the same car using Flashfuel.”
    2. The manipulated variable would be the fuel brand.
    3. 1 car, specific distance driven
    4. Same car, same distance and driving conditions.
    5. Miles per gallon
  7. Data Interpretation
    1. Yes, same distance was driven in both tests
    2. Petrozip
    3. biology13

Lesson 20

  • DNA has sections that signal for the beginning of a coding sequence as well as a DNA section that signals for the ending of a coding sequence. The possibility of damage to the DNA is minimized by having only small sections opened up at any time.
  • Hummingbirds can beat their wings fast enough to hover in midair and they have long bills and tongues which allow them to drink from the nectar of flowers.
  • The nervous system is a complex network of nervous tissue that carries electrical messages throughout the body.
  • Skeletal muscle responds to nervous system signals and interacts with the skeleton to causes Voluntary muscle contraction.
  • Plastids, Cytoplasmic organelle
    in plants, bounded by a double membrane that carries its own DNA and is
    often pigmented. Chloroplasts are plastids.
  • Cholesterol is the component of the cell membrane provides stability.
  • Since oxygen is not very soluble in water (the major constituent of blood), an oxygen transport protein must be used to allow oxygen to be ‘soluble’.  Hemoglobin (Hb) is the oxygen transport protein used in the blood of vertebrates.
  • The peroxisome gets rid of toxic peroxides and digests fatty acids. The lysosome digest proteins (these can be membrane proteins i.e. receptors).
  • The fungus just grows on its food. They secrete a wide range of extracellular enzymes into the environment to increase the availability of the nutrients they need (eg., ligninase, hemicellulase, amylase, chitinase, keratinase) which is how they contribute to nutrient recycling in nature.
  • Secreted proteins are produced “in” the ER. When transcription is about to occur a ribosome interacts with the ER and “inserts” a protein in it.  This protein is then transported through vesicular transport to the golgi for further processing.  Soluble proteins of the cell are produced in the cytoplasm by free ribosomes.
  • All the proteins are transported between organelles through membrane trafficking (vesicular transport) which involves the cytoskeleton (microtubules) as well as proteins that “carry” the vesicles along the microtubules.
  •  The double membrane structure of the mitochondria allows for the isolation of H+.
  • Endocytosis. This is a very complex process involving receptors (receptor mediated endocytosis) the cytoskeleton as well as many proteins that “tag” the vesicles for transport to appropriate parts of the cell.
  • Prokaryotic cells are cells without a nucleus and are found in single-celled organisms
    Eukaryotic cells are cells that contain a nucleus. Eukaryotic cells have other organelles besides the nucleus. The only organelles in a prokaryotic cell are ribosomes and are found in multi-celled organisms.
  • In vascular plants, stems are the organs that hold plants upright so they can get the sunlight and air they need.
  • Flagella and cilia.

Lesson 21

  1. Electron microscope
  2. 1-All organisms are composed of cells.  2-Cells are alive and the basic living units of organization in all organisms.  3-All cells come from other cells.
  3. NO, because all cells come from other cells

Lesson 31

  1. The process of diffusion is molecules are said to flow down their concentration gradient, flowing from an area of high concentration to an area of low concentration.
  2. The diffusion of water across a membrane because of a difference in concentration is called osmosis.
  3. A hypertonic solution means the environment outside of the cell has more dissolved material than inside of the cell. If a cell is placed in a hypertonic solution, water will leave the cell. This can cause a cell to shrink and shrivel.

Lesson 33

  1. c
  2. b
  3. a
  4. b
  5. b
  6. a, a, a, b
  7. a
  8. When celery is placed in tap water (hypotonic), the water will flow into the celery, making it swell. When celery is placed in sugar water (hypertonic), water will flow out of the celery into the sugar water, making the celery shrivel.
  9. left

Water will flow from the 85% water cell into the 70% water solution (shown).
Water will flow from the 2% salt cell into the 25% salt solution.
Water will flow from the 90% water solution into the 14% salt (86% water) cell.
Water will flow from the 2% NaCl (98% water) cell into the 10% glucose (90% water) solution.

Lesson 38

  2. Water is polar because the charges are unevenly distributed with negative charges on the oxygen end of the molecule and positive charges on the hydrogen end of the molecule.
  3. True
  4. The polarity of individual water molecules causes opposite ends to attract each other like magnets.
  5. False – A hydrogen bond is stronger than an ionic bond.
    True – The attraction between the hydrogen atom on one water molecule and the oxygen atom on another water molecule is an example.
    False – A hydrogen bond is stronger than a covalent bond.
    False – They are the strongest bonds that form between molecules.
  6. Cohesion is the attraction of like molecules. Adhesion is the attraction of unlike molecules.
  7. capillary action
  8. Capillary action makes it possible for water to flow up plant tubules from roots to leaves (against gravity).
  9. Water’s polarity gives it the ability to fit between the atoms of other polar or ionic substances, dissolving them.
  10. In a sugar-water solution, water is the solvent and sugar is the solute.
  11. Water can dissolve
    √ polar
    ❏ non-polar
    √ ionic
    √ hydrophilic
    ❏ hydrophobic
  12. Solid water is less dense than liquid water, so ice floats in water.
  13. When ice forms at the top of a body of water, it insulates organisms at the lower levels.
  14. cooling agent for living things
  15. Water’s high specific heat means that it is slow to change temperature. This allows large bodies of water to maintain a relatively stable temperature, protecting the organisms living in them from severe temperature changes and regulating temperatures of nearby landmasses. It also helps maintain stable body temperature.
  16. H+ and OH
  17. Water has an equal amount of H+ and OH– ions, making it neutral.
  18. The pH scale indicates the concentration of hydrogen and hydroxide ions in solutions.
  19. Acid
    pH range: 0-7
    Examples: (vary) coffee, lemon juiceBase
    pH range: 7-14
    more OH- than H+
    Examples: (vary) bleach, drain cleanerWater
    equal amounts of OH- and H+
  20. ten
  21. Changes in pH can disrupt cells’ chemical reactions and homeostasis.
  22. Buffers are weak acids and weak bases that work to neutralize stronger acids and bases.

Lesson 44

  1. All organic chemical compounds possess one thing in common; all of them contain the element is Carbon.
  2. The Carbohydrates are made up of three different elements in a ratio of 1:2:1. In order, these elements are its carbon, hydrogen, and oxygen.
  3. A simple sugar called_Glucose_, whose chemical formula is C6H12O6 is broken down during glycolysis.
  4. Anabolism is the process of building up larger molecules from smaller ones. Anabolism is a metabolic function.
  5. The three elements make up lipids are carbon, hydrogen, and oxygen.
  6. Energy is stored in the chemical bonds of lipids.
  7. Proteins are made up of chains of simple molecules called Amino Acids.
  8. Enzymes are the protein molecules which are involved in the metabolic reactions in the body. (To accelerate action in the body. There are many different kinds with very specific roles-ranging from energy production to DNA replication.)
  9. Nucleic Acids are made up of chains of simple molecules called nucleotides.
  10. The nucleus of a eukaryotic cell contains the DNA, the genetic material of the cell. The DNA contains the information necessary for constructing the cell and directing the multitude of synthesis tasks performed by the cell in the process of life and reproduction.  (The nucleus is the “brain” of the cell, it controls all the cell’s activities) (this is the best answer we could come up with, if you learned something different please let me know)

Lesson 48

  1. polarity: the unequal distribution of charges on a molecule
  2. cohesion: the attraction of like molecules such as the attraction of water molecules to each other.
  3. solvent: the substance in which the solute is dissolved within a solution
  4. Organic compounds are compounds that have carbon and are found in living things

Lesson 54

  1. The purpose of cellular respiration in plants and animals is to break down sugar from food (glucose) and turn it into energy.
  2. Cellular respiration takes place in the cytoplasm and mitochondria of cells.
  3. Carbon dioxide is the waste produce of cellular respiration.
  4. a) Photosynthesis takes place in the chloroplasts. Cellular respiration takes place in the cytoplasm and mitochondria.
    b) The waste product of photosynthesis is oxygen. The waste product of cellular respiration is carbon dioxide.
    c) Carbon dioxide and water are required for photosynthesis. Glucose and oxygen are required for cellular respiration.
    d) Electron transport chains are used for creating energy (ATP).
    e) ATPase drives the synthesis of ATP.

Lesson 59

  1. There are two separate parts of a chloroplast: the space inside the chloroplast itself, and the space inside the thylakoids
    1. The inner compartments inside the thylakoids are called the thylakoid space (or lumen). This is the site of the first part of photosynthesis.
    2. The interior space that surrounds the thylakoids is filled with a fluid called stroma. This is where carbon dioxide is used to produce glucose, the second part of photosynthesis.
  2. If the stomata of a plant leaf were glued shut Carbon Dioxide would not be able to enter the leaf. Carbon Dioxide is one of three reactants needed to begin the photosynthesis process.
  3. The reactants of photosynthesis are carbon dioxide and water. The products of photosynthesis are glucose and oxygen.
  1. Chloroplasts, the organelles which conduct photosynthesis in plants and algae.
  2. Each chloroplast contains neat stacks called grana (singular, granum). The grana consist of sac-like membranes, known as thylakoid membranes. These membranes contain photosystems, which are groups of molecules that include chlorophyll, a green pigment. The light reactions of photosynthesis occur in the thylakoid membranes. The stroma is the space outside the thylakoid membranes, as shown in Figure below. In addition to enzymes, two basic types of molecules-pigments and electron carriers–are key players in this process. This is where the reactions of the Calvin cycle take place.
  3. Electron Carrier is a molecule which transfers energy-carrying electrons within an electron transport chain. Electron Transport Chain (ETC) is a A series of electron-carrying molecules which accept and pass along energy-carrying electrons in small steps, allowing the energy lost at each transfer to be captured for storage or work.

Lesson 62

  1. Glycolysis
  2. True
  3. Cellular respiration is a cellular process that requires oxygen and gives off carbon dioxide in order to obtain energy for the organism.
  4. The formula for aerobic cellular respiration is C6H12O6 + O2 → CO2 +H2O + Energy (as ATP)            The word equation for this is:     Glucose + Oxygen → Carbon dioxide + Water + Energy (as ATP)
  5. Fermentation is the process that releases energy from food molecules by producing ATP in the absence of oxygen.
  6. Anaerobic
  7. Alcoholic Fermentation and Lactic Acid Fermentation
  8. Alcohol fermentation is a process that uses yeast and bacteria. They work together to convert sugars into ethyl alcohol and carbon dioxide. The fermentation begins after glucose enters the cells and broken down into pyruvic acid.  The pyruvic acid is then turned into CO2, ethanol, and energy.
  9. They use up the ATP produced by cellular respiration; they produce it by lactic acid fermentation.
  10. Lactic Acid Fermentation can supply the ATP
  11. Because they are using oxygen at a rate faster than the lungs and heart are able to match. This activity is known as “anaerobic” (without oxygen). Muscles are designed to work this way for extreme bursts of power and speed. But oxygen is ultimately required to make the body work, so after the race, you must replenish the oxygen within the body.
  12. The process that withdraws energy
  13. Photosynthesis removes carbon dioxide from the air and cellular respiration puts it back.
  14. Photosynthesis releases oxygen into the atmosphere and cellular respiration uses the oxygen to release energy from food.

Lesson 63

  1.  It comes from sunlight plants use photosynthesis to capture energy from sun, animals eats plants *1st level consumers*, then so on and on
  2. Type — Description  — Examples
    Autotrophs — Organisms that makes their own food — Moss
    Heterotrophs —Organisms that obtain energy from the food they eat — zebra
  3. ATP is adenosine triphosphate. This chemical compound is what living things use to store energy ADP stored in the body so when it’s time to use that stored energy, ADP goes through ATP synthesis to make ATP and use that energy though the body.
  4. ATP (adenine triphosphate) is the compound responsible for providing energy to a cell to carry out its metabolic process. When the ATP molecule is in contact with a water molecule (hydrolysis), the result is ADP (adenosine diphosphate) and a phosphate. In this reaction, energy is released to the cell. The ADP molecule is further broken down to AMP (adenosine monophosphate) and a phosphate through hydrolysis, releasing further chemical energy.
  5. Adenine, Ribose, Phosphate Groups
  6. Cells create and store energy in different ways. Cells are able to store small amounts of energy through a molecule called adenosine triphosphate.
  7. ATP is a kind of chemical substance in living organisms. It stores energy in its phosphate bonds. When these phosphate bonds are broken, energy is released that is made available for biological processes.
  8. a. ADP
  9. Six molecules of water plus six molecules of carbon dioxide produce one molecule of sugar (called glucose) plus six molecules of oxygen.
  10. 6H2O + 6CO2  –> C6H12O6+ 6O2
  11. sugars and oxygen
  12. light
  13. chlorophyll
  14. Thylakoids
  15. A stacked membranous structure within a chloroplast that contains the chlorophyll and is the site of the light reactions of photosynthesis.
  16. Stroma
  17. light reactions and dark reactions
  18. Temperature, Carbon dioxide, Light energy
  19. False

Lesson 67

  1. binary fission, fragmentation, and budding.
  2. A gamete is haploid, meaning that it contains only 1 complete set of chromosomes. Therefore, a gamete has only 1 allele for each gene. A zygote is the single cell that forms after sperm fertilizes an egg cell. A zygote is a diploid cell, formed from the union of two haploid cells.  Gamates have half the number of chromosomes from each parent cell.  That is 23 from father and 23 from mother, which makes 23 pairs in the daughter cell. A normal human zygote has 46 chromosomes. 23 from each of the parents.
  3. The process in which two gametes unite
  4. Give at least one thing they have in common and one way that they are different.

Lesson 72

Mitosis worksheet

Lesson 74

  1. They code for varying alleles for the same traits, one from each parent.
  2. a, 2N – Why? It is because diploid cells have 2 sets of chromosomes, designated 2N.
  3. b, 4 – Haploid is one-half of the diploid number.
  4. Meiosis divides chromosome number and reduces it by half.
  5. The two stages are Meiosis I and Meiosis II.
  6. True! Meiosis results in four haploid cells.
  7. Homologous chromosomes move together and attach at their centromeres.
  8. c, 4 – Each chromosome is two chromatids and a tetrad is composed of two chromosomes.
  9. Crossing over exchanges alleles and allows for genetic variation in offspring.
  10. a, b, c – After meiosis II daughter cells are haploid
  11. Haploid gametes produced in males – sperm. Haploid gametes produced in females ova. Cells that do not participate in reproduction that are produced in females – polar bodies.
  12. c, d
Lesson 83
  1. The process of the replication of DNA
  2. Protein
  3. Helicase
  4. A=T and G=C
  5. FOUR
  6. C=G, A=T, T=A, G=C, G=C, G=C, C=G, T=A, C=G, C=G, A=T
  7. C=G, A=T, T=A, G=C, G=C, G=C, C=G, T=A, C=G, C=G, A=T
  8. Yes
  9. Millions of base pairs
  10. 3 Billion Pairs
  11. Nucleus
  13. Ladder
  14. Enzymes and Special Proteins
  15. C=G, G=C, A=T, U=A
  16. A=T, U=A, G=C, G=C, G=C, G=C, C=G, U=A, C=G, C=G
  17. The RNA Molecule is on the right side on the diagram
  18. 100 to 10,000 bases long
  19. Messenger RNA
  20. It moves away from the DNA and leaves the cell nucleus
  21. To a ribosome in the cytoplasm
  22. The cells structure for constructing proteins
  23. mRNA bases that are grouped in sets of three
  24. a complementary set of bases that are apart of tRNA
  25. Amino Acids
  26. Methionine (Met)
  27. AUG-UAC
  28. CCG,GGC
  29. Glycine
  30. The ribosome will move to the right
  31. The first tRNA will float away from the ribosome leaving its amino acid behind
  32. AGG=UCC
  33. Serine
  34. Three amino acids long
  35. 100-10,000 amino acids long
  36. when a special stop Condon is reached
  37. The ribosome will release the polypeptide

Lesson 85

  1. mRNA carries the instructions from the nucleus to the cytoplasm.
  2. DNA in the nucleus contains the instructions to create all the proteins we need for our bodies. RNA are the messengers that DNA sends out to the rest of the cell so that proteins can be made.
  3. rRNA make up the ribosome, which is the site of protein synthesis. tRNA are responsible for ordering the amino acids.

Lesson 87

  1. RNA has ribose sugar instead of deoxyribose. RNA is generally single-stranded, instead of double-stranded. RNA contains uracil in place of thymine.
  2. most are involved in protein synthesis
  3. Messenger, is part of ribosomes, Transfer RNA
  4. C & D
  5. Amino acids
  6. The genetic code is read 3 letters at a time, so that each “word” of the coded message is three bases long.
  7. a sequence of three bases that codes for one amino acid
  8. c. 64
  9. False
  10. The cell uses information from the messenger RNA to produce proteins.
  11. On the ribosomes
  12. Enzymes
  13. False
  14. a permanent change in the DNA sequence of a gene.
  15. Point mutation

Lesson 94

  1.      A   a
    a  Aa aa
    a  Aa aa
  2.        N    n
    N  NN  Nn
    n   Nn  nn
  3.        T     t
    T   TT   Tt
    t    Tt    tt
  4. (given)
  5. Cross (parents): Pp x pp
    P     p
    p   Pp   pp
    p   Pp   pp
    Genotype ratio: 2Pp : 2pp
    Phenotype ratio: 2 yellow : 2 green
  6. Cross (parents): FF x ff
    F     F
    f    Ff   Ff
    f    Ff   Ff
    Genotype ratio: all Ff
    Phenotype ratio: all white

Lesson 95

    1. HO HE HE HE
      HE HO HE HO
      HE HO HO HO
      HE HO HE HE
    2. purple brown
      purple brown
      white blue
      round long
      round long
      wrinkled bobtails
    3. SS PP
      Ss Pp
      ss pp
    4. 1/2 or 50%
      75% or 3/4
      all or 100%
    5. all tall
    6. 25%
    7. 1/2 or 50%
    8. RR x rr, 0%, Rr
    9. all white
    10. pp x Pp, 50% purple
    11. Pp x Pp, 75% purple
      25% white
    12. Hh, HH, hh
      Hh x Hh, 75%, 25%

Lesson 97

A. (given)

B. Cross (parents): Tt x Tt
T     t
T   TT  Tt
t    Tt   tt
Genotype ratio: 1 TT : 2 Tt : 1 tt
Phenotype ratio: 3 tongue curlers : 1 non-tongue curlers

C. Cross (parents): NN x nn
N    N
n   Nn  Nn
n   Nn  Nn
Genotype ratio: 100% Nn
Phenotype ratio: 100% normal vision

D. Cross (parents): Rr x Rr
R    r
R   RR  Rr
r    Rr   rr
Genotype ratio: 1 RR : 2 Rr : 1 rr
Phenotype ratio: 1 red : 2 pink : 1 white

F. Cross (parents): FF x ff
F    F
f    Ff   Ff
f    Ff   Ff
Genotype ratio: 100% Ff
Phenotype ratio: 100% mild frizzle

G. Cross (parents): Dd x Dd
D      d
D    DD   Dd
d    Dd    dd
Genotype ratio: 1 DD : 2 Dd : 1 dd
Phenotype ratio: 1 lethal : 2 dwarf : 1 normal
25% is the probability that the children born to them will be of normal height.

H. Cross (parents): Ww x Ww
W         w
W   WW    Ww
w    Ww    ww
Genotype ratio: 1 WW : 2 Ww : 1 ww
Phenotype ratio: 1 lethal : 2 wrinkled : 1 smooth

Lesson 108

An ___autotroph__ is an organism that makes it own __food__.
__Producers__ are also called autotrophs. __Heterotrophs__ are
organisms that get their energy by eating other __organisms__.
__Consumers__ are also called heterotrophs. All organisms get their
energy from the __sun__. Producers get __direct__ energy
from the sun. Consumers get __indirect__ energy from the sun by
___eating__ producers or other organisms that eat producers.

Lesson 172

1. What is an angiosperm? flowering plant

2. The flower attaches to what part of the plant? receptacle

3. Why are flowers brightly colored? attract insects

4. Name two mammals that might pollinate a plant. bats, mice (birds aren’t mammals but I usually accept as an answer)

5. If the petals of a flower are reduced or absent, how is the plant pollinated? wind

6. The female reproductive structures are called the: pistil or carpel

7. Name the three parts of the pistil: stigma, style, ovary

8. Where are the ovules stored? ovary

9. Name the two parts of the stamen: anther and filament

10. Describe sexual reproduction in plants. pollen travels from the male part of the flower to the stigma of the female part

11. The ovary develops into what structure? fruit

12. Define fruit. part of the plant that carries seeds, it was originally the ovary of the flower

13. Some flowers are not brightly colored at all, but have a very pungent odor that smells like rotting meat. How do you think these flowers are pollinated? flies

14. In many flowers, the pistils and stamens reach maturity at different times. Considering what you know about pollination, why would this be an advantage to the plant? prevents self fertilization

**Coloring should be graded according to the directions**