Heredity
The notation TT means an organism has two ________ alleles.
What is dominant?
A Punnett square shows _________?
What is all of the possible outcomes (offspring) of a genetic cross?
Incomplete dominance occurs when__________. An example would be_________
What is when one allele is only partially dominant (combination of the two traits). Example: Red and white parents yield pink offspring.
The process in which a parent cell divides twice to produce gametes is ________________.
What is meiosis?
A ____________________ organism is the offspring of many generations of organisms that have the same trait.
What is a purebred/homozygous?
Physical characteristics that are studied in genetics are called ______.
What are traits?
What is the probability of producing a tall pea plant from a genetic cross between two hybrid tall pea plants?
What is 3/4 or 75%?
Codominance is when_____________. An example would be____________
What is when both alleles for a gene are expressed equally (neither recessive nor dominant). An example: A black parent crossed with a white parent yield offspring with black and white patches.
The gamete cells created during meiosis have ________ the number of chromosomes as parent cells.
What is half?
If a ___________________ allele is present, its trait will appear in the organism.
What is dominant?
When Mendel crossed purebred short plants with purebred tall plants, all of the offspring were ________________.
What is Tall and heterozygous? (or hybrid)
An organism's genetic makeup.
What is its genotype?
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. This pattern of inheritance is called ____________
What is codominant?
Meiosis is different from mitosis because ____________
Acceptable answers: Mitosis produces 2 body cells with 46 chromosomes in each, meiosis produces 4 gametes with 23 chromosomes in each. Or, mitosis replicates body cells, while meiosis creates gametes.
Gregor Mendel was the first scientist to recognize that the principles of _______________ can be used to predict the results of genetic crosses.
What is probability?
Gregor Mendel used this technique to study the inheritance patterns of pea plant traits.
What is cross-pollinate?
In pea plants, tall height is controlled by a dominant allele. Short height is controlled by a recessive allele. Therefore a tall plant can _______ be a hybrid. (Never, sometimes, always)
What is "sometimes?" Now, for full credit, explain why this is the case.
Of the following traits, one 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.
What is the ability to sing well.
The Law of Heredity that states that every organism has two alleles for each gene, and when gametes are produced, the alleles separate. (Each gamete only gets one allele).
What is the Law of Segregation?
Explain the purpose of meiosis.
Meiosis ensures that each gamete 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.
The Law of Heredity that states that genes for different traits are sorted separately from one another so that the inheritance of one trait is not dependent on the inheritance of another. (For example, the trait for eye color does not depend on the trait for height).
What is the Law of Independent Assortment?
In experimental field of F2 generation offspring (Ww x 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, not what WILL happen. Since there are only 200 plants in the experimental field, you cannot expect exactly 1 out of 4 plants, or 25%, to be purple.
Only changes in ___________ cells can be passed to offspring.
What is changes in sex cells.
The name of the theory that states genes are carried from parents to offspring on chromosomes.
What is the chromosome theory of inheritance?
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.