Download 7th Grade Science: Semester Review

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7 Grade Science: Semester Review – Spring 2013
Part III: Due Wednesday, May 29th
The final exam will cover the following topics:
1. Heredity and Genetics
2. Natural Selection, Modern Genetics,
Classification & Dichotomous Keys
3. Survival and Adaptations
4. Matter & Energy Cycles (Ecology)
5.
6.
7.
8.
Biomes and Water Ecosystems (and Succession)
Weathering, Erosion, Deposition, and
Catastrophic Events
Texas Ecoregions, and Water
Space, The Final Frontier
Not all of this information is in your book. Textbook pages are provided that can help you, however your old class notes will
be the best place to find these answers. Vocabulary for Part III is at the end of this packet .
Heredity and Genetics (pages 543-547)
1. Where is the DNA molecule found in the cells? In the chromosomes of the nucleus
2. What is the shape of a DNA molecule? Double Helix
3. What is the function of the DNA? DNA is the genetic material that carries information about the organism.
4. Sexual reproduction involves two parents who combine their genetic material to produce a new organism,
which is genetically different from both parents. Asexual reproduction requires only one parent, and the
offspring are genetically identical to the parent and to each other. Some organisms who reproduce asexually
simply divide in half.
5. Characteristics that are passed from parents to offspring are traits.
6. The passing of traits from generation to generation is heredity. The study of heredity is genetics.
7. What is a gene? A segment of DNA that codes for a specific trait
8. In pea plants (studied by Gregor Mendel, the Father of Genetics!) smooth seed are dominant over wrinkled
seeds. Predict the results of crossing a hybrid parent with a pure recessive parent. First, draw the Punnett
S
s
square of the cross.
Hint! First decide
what letter to use.
Remember the
letter comes from
the dominant trait.
s
s
s
Ss
ss
Ss
ss
9. What are the two alleles (versions of a gene) involved in this genetic cross? Smooth and wrinkled seeds
10. What is the percent chance of producing offspring with the following characteristics?
a. pure for smooth seeds 0%
d. SS 0%
b. hybrid 50%
e. Ss 50%
c. wrinkled seeds 50%
f. ss 50%
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11. Define the words AND give an example.
a. Genotype The genetic makeup of an organism Ss
b. Phenotype The physical appearance of an organism Smooth seeds
c. Hybrid An organism with one dominant and one recessive gene for a trait Ss
d. Pure An organism with either 2 dominant genes or 2 recessive genes for a trait SS or ss
e. Dominant The gene that will show and is represented with a capital letter
f. Recessive The gene that will be masked by a dominant gene and is represented by a lower case letter
Natural Selection, Modern Genetics, Classification & Dichotomous Keys
1. A genetic trait or characteristic that helps an organism survive and reproduce in its environment is known as a
adaptation.
2. Any difference between organisms of the same species is known as variation. Natural selection works on these
variations so that the organisms better adapted are more likely to survive and reproduce than other members
of the same species.
3. Selective breeding is the process of selecting a few organisms with desired traits to serve as parents of the next
generation.
4. Genetic changes can occur in generations over time. Is this more likely to occur in sexual reproduction or
asexual reproduction? Why? Sexual reproduction because there are two parents (with different traits) that are
giving chromosomes to their offspring.
5. The separation of populations by barriers such as rivers, mountains, or bodies of water is called what?
Geographic isolation
6. True or False: A mouse can adapt by changing its fur color from white to brown. False
7. Use the scientific name for bottlenose dolphins, Tursiops truncatus, to answer the following questions.
a. What is the genus name? Tursiops
b. What is the species name? truncatus
c. What is the correct way to abbreviate the scientific name? T. truncatus
d. What is the common name of this organism? Bottlenose dolphin
8. Why do scientists use binomial nomenclature for naming living organisms?
So that everyone on earth (no matter what language they speak) knows the organism by the same name.
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9. Use the dichotomous key to identify the following insects.
A1. Wings are present ...................................... Go to B
A2. Wings are not present ................................ Go to E
B1. Wings have hard covering .......................... Coleoptera
B2. Wings are delicate and membranous ........ Go to C
C1. Wings spread out from body ...................... Odonata
C2. Wings extend over the body ...................... Go to D
Hymenoptera
Diptera
D1. Hind legs adapted for hopping................... Orthoptera
D2. Hind legs not adapted for hopping ............ Diptera
E1. Distinct body segments .............................. Hymenoptera (head, thorax, abdomen easily recognizable)
E2. Body segments are not distinct .................. Isoptera (head, thorax,
abdomen not easily recognizable)
Survival and Adaptation
1. What concept is being shown by the picture to the right? Turgor pressure
What type of adaptation is this? physiological
2. Remember, any difference between organisms of the same species is known as
a variation. These variations within a population give rise to an adaptation - a
trait that helps an organism survive and reproduce better than other members of the same species.
3. Name each of the animal adaptations below based on its description:
a) Structural adaptations refer to an animal’s body plan, the way its parts are constructed or arranged.
b) Physiological adaptations involve physical and chemical processes inside an organism.
c) Behavioral adaptations are an activity or action that generally helps an organism to survive.
4. Structural adaptations can be internal or external. Complete the following table from your animal adaptations
notes:
Internal (Structural)
External (Structural)
Mammals
Lungs
Teeth Shape
Highly developed brain and
Nervous system
Hair
Camouflage
Birds
Hollow bones
Highly developed sense organs
Feathers, beak shape, wing shape
Camouflage
Fish
gills
jaws, fins, camouflage
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5. Behavioral adaptations can be instinctive or learned. The two instinctive behaviors we studied were migration
and hibernation. Instinctive behaviors are carried in the organism’s DNA and are performed correctly the very
first time they are attempted. Learned behavioral adaptations are the process that leads to changes in behavior
based on practice or experience. The bigger the brain, the more an animal can learn.
6. Physiological adaptations in animals include life cycles, a series of stages that an
organism passes through as it develops from birth to adulthood. These stages are the
result of chemical changes in the body, and going from one stage to the next in the life
cycle is known as metamorphosis. The life cycle of a butterfly is diagramed here,
showing four distinct stages: egg, caterpillar, pupa, and adult.
7. Plant adaptations also include structural, physiological, and behavioral adaptations.
Structural adaptations include the vascular tissues of phloem, which carries food produced in the leaves to the
rest of the plant, and xylem, which carries dissolved minerals and water from the roots of the plant up to the
leaves. These tissues are two of the internal structural adaptations in plants.
8. The basic tissues that make up a plant are the roots, stems, and leaves.

Roots anchor the plant in the ground and absorb nutrients and water from the soil.

The stem supports the plant to hold up the leaves to the sun and carries substances back and forth
between the roots and leaves.

Leaves provide a source of food for the plant, where photosynthesis occurs in the chloroplasts of plant
cells.
9. Structural adaptations for reproduction include seeds, flowers, and bulbs.
10. Physiological adaptations for plants include turgor pressure (shown in question #1 of this section) and
photosynthesis, where a plant makes its own food using carbon dioxide and water and energy from the sun.
Turgor pressure is maintained in plant cells by water in the cell’s central water vacuole exerting pressure on the
cell wall. If a plant does not have enough water it will not be able to maintain turgor pressure and the plant will
wilt.
11. Behavioral adaptations of plants include the following:
a.
Geotropism - the growth of an organism in response to gravity,
b. Phototropism - the growth of an organism in response to light
c. Thigmotropism - the growth of an organism in response to touch
d. Dormancy - a temporary stop in the growth and development of a plant in response to
environmental conditions.
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12. In general, adaptations help an organism survive and reproduce in their environment. Identify each of the
following adaptations as being primarily for:
A) Obtaining food
B) Escaping/surviving predators
C) Reproduction.
i) A wolf’s sharp claws, speed, and excellent hearing and eyesight. A
ii) A penguin’s caring for its young until the young can survive on its own. C
iii) A box turtle’s hard shell. B
iv) The flower on a plant producing nectar to attract bees. C
Part III Vocabulary
Genetics
DNA
cells
nucleus
chromosome
gene
trait
characteristic
Watson and Crick
double helix
heredity
genetics
allele
dominant allele
recessive allele
Gregor Mendel
species.
offspring
inherited
generation
sexual reproduction
diverse
asexual reproduction
uniform
clone
fertilization
adaptation
mutation
pure
hybrid
Punnett square
Phenotype
Genotype
Ethics
Natural Selection/Modern
Genetics
species
population
gene pool
variation
mutations
adaptation
natural selection
Charles Darwin
extinction
selective breeding
domesticated
cloning.
genetic engineering
theory
Physiological Adaptation
Behavioral Adaptation
Adaptation
Migration
Hibernation
Gills
Instinct
Learning
Life Cycle
Metamorphosis
Cellular Respiration
Vascular Tissue
Xylem
Phloem
Root
Stem
Leaf
Chlorophyll
Turgor Pressure
Photosynthesis
Seed
Geotropism/Gravitropism
Phototropism
Dormancy
Bulb
Survival/Adaptations
Structural Adaptation
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