Lesson 3.1: Heredity
Lesson 3.2: Probability and Heredity
Lesson 3.3: Patterns of Inheritance
Lesson 3.4: Chromosomes and Inheritance
Fun Bucket
100
What does the notation TT mean to geneticists?
Two dominant alleles
100
What does a Punnett square show?
What is all of the possible outcomes of a genetic cross
100
Explain incomplete dominance and give an example.
Incomplete dominance occurs when one allele is only partially dominant (combination of the two traits).
100
The process in which a parent cell divides twice to produce sex cells is ________________.
What is meiosis.
100
A ____________________ organism is the offspring of many generations of organisms that have the same trait.
What is a purebred/homozygous.
200
Which term refers to physical characteristics that are studied in genetics?
What are traits.
200
What is the probability of producing a tall pea plant from a genetic cross between two hybrid tall pea plants?
3/4 or 75%
200
Explain codominance and give an example.
Codominance occurs when both alleles for a gene are expressed equally (neither recessive nor dominant).
200
TRUE or FALSE: The sex cells created during meiosis have twice the number of chromosomes as parent cells.
FALSE: The sex cells created during meiosis have HALF the number of chromosomes as parent cells.
200
If a ___________________ allele is present, its trait will appear in the organism.
What is dominant.
300
When Mendel crossed purebred short plants with purebred tall plants, all of the offspring were ________________.
Tall- hybrids
300
What is genotype?
An organism's genetic makeup.
300
A purebred chicken with white feathers is crossed with a purebred chicken that has black feathers. Each of their offspring has both black and white feathers. Why does this happen?
Both alleles for feather color are recessive.
300
How are mitosis and meiosis different?
Answers will vary. Examples: Mitosis produces 2 body cells with 46 chromosomes in each, meiosis produces 4 sex cells with 23 chromosomes in each.
300
TRUE or FALSE: A pea plant that is heterozygous for tall stems that has the alleles Tt.
What is true.
400
What did Gregor Mendel do to study different characteristics in his genetic experiments?
Mendel cross-pollinated plants with different traits.
400
In pea plants, green pod color is controlled by a dominant allele. Yellow is controlled by a recessive allele. Explain why a plant with yellow pods can never be a hybrid.
Because the allele for yellow is recessive, plants with yellow pods must have two recessive alleles. A hybrid would have one dominant allele and one recessive allele, and would therefore be green.
400
Which of the following traits is influenced by both inheritance and environmental factors? 1. The ability to sing well. 2. The ability to cough. 3. Natural hair color. 4. Dyed hair color.
1. The ability to sing well.
400
What was the name of the scientist who studied the cells of grasshoppers.
Who is Walter Sutton.
400
Explain the function of meiosis.
Meiosis ensures that each sex cell gets half the number of chromosomes in a body cell. If meiosis did not occur, the sperm cell and the egg cell would each have the same number of chromosomes as a body cell. When the two cells combined, the offspring would have twice the normal number of chromosomes.
500
Mendel used the principles of ________________ to predict what percent of offspring would show a particular trait.
Probability.
500
In experimental field of F2 generation offspring (Ww + Ww), a researcher counted 62 plants with purple (recessive, ww) flowers out of a total of 200 plants, or 31% purple plants. Explain how this is possible
Probability describes what is likely to occur for a large number of trials. Since there are only 200 plants in the experimental field, you cannot expect exactly 1 out of 4 plants, or 25%, to be purple.
500
Only changes in ___________ cells can be passed to offspring.
Only changes in sex cells can be passed to offspring.
500
Explain the chromosome theory of inheritance.
Genes are carried from parents to offspring on chromosomes.
500
A woman gives birth to a son. Two years later, she gives birth to another son. What is the probability that her third child will be a girl? Explain your reasoning.
The probability is 1 in 2, or 50 percent. The two possible results—having a boy or having a girl—are equally likely with each birth. Because each birth is an independent event, the probability that one result will occur does not depend on previous births.
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