Which process allows sexually reproducing organisms to create gametes with half the number of chromosomes of the body cells? • Mitosis • Meiosis • Fertilization • Reproduction
A branch cut off of a geranium plant grows into a new plant. Will the new plant be different from its parent plant? • yes, because mitosis will take place in the new plant • yes, because meiosis will take place in the old plant. • no, because meiosis and fertilization did not take place. • no, because the new plant was formed from gametes.
Cats have many different possible coat colors. What does this show? • mutations occurring in sexually reproducing organisms • reproduction in asexually reproducing organisms • division of body cells in adult organisms • variation in sexually reproducing organisms
What is true of asexual reproduction? Offspring that • are identical to their parents. • resemble their parents. • are quite different that their parents. • are random and can have different results each time.
What is the result of a single cell going through the process of meiosis? • one identical new cell • two identical new cells • three identical haploid bodies • four gamete cells
What is an advantage of asexual reproduction? • the offspring are not identical to their parents • the offspring are identical to their parents • there are more offspring produced • there are fewer offspring produced
Where are genes for sex-linked traits located? • They can be on any chromosome • On the “Y” chromosome • On the “X” chromosome • On chromosome pair # 21
A white flower crossed with a red flower produces pink offspring. This is an example of incomplete dominance. If two of the pink-flowered plants are crossed, what ratio will the genotypes of the offspring have? • 1 RR: 3 Rr • 1 RR: 2 Rr: 1 rr • 2 Rw: 2 Ww • 3 Rr: 1 rr
Why are blood types considered an example of codominance? • there are four types of blood, not two • blood type O can be donated to anyone, AB cannot • blood types A and B will both be expressed when present • there are three alleles for blood type and four types of blood
How many pairs of homologous chromosomes do humans have? • 4 • 22 • 46 • 52
If two different alleles are present, which allele is expressed? • Recessive • Dominant • Phenotype • Genotype
A tall pea plant (DD) and a tall pea plant (Dd) have what in common? • Phenotype • Genotype • Alleles • Seed color
In crossing homozygous dominant and homozygous recessive pea plants, Mendel noted that some genes were not seen in the F1 generation and were seen in only 25% of the F2 generation. What did he call these genes? • Dominant • Recessive • Lethal • Incompletely dominant
One cat carries heterozygous, long-haired traits (Ss), and its mate carries homozygous short-haired traits (ss). What is the probability of one of their offspring having long hair? • 100% • 75% • 50% • 25%
A person with phenotype O blood has how many possible genotypes? • 6 • 1 • 3 • 2
Which pair of chromosomes produces a female offspring? • a female Y chromosome and a male Y chromosome. • a female Y chromosome and a male X chromosome. • a female X chromosome and a male X chromosome. • a female X chromosome and a male Y chromosome.
Crossing a snap dragon that has red flowers with one that has white flowers produces a snap dragon with pink flowers. The trait for flower color exhibits • Codominance • Incomplete dominance • Multiple alleles • Complete dominance
On which of the following chromosomes would a sex-linked trait most likely be found? • X • Y • O • YO
An organism that has two identical alleles for the same trait is called _______ for that particular trait. • Homozygous • Heterozygous • Dominant • Recessive • codominant
In a heterozygous individual the allele being expressed is • recessive. • masked. • redundant. • dominant.
Let P = purple flowers and p = white, and T = tall plants and t = dwarf. What would be the appearance of a plant with the genotype PpTt? • purple flowers, tall • purple flowers, dwarf • white flowers, tall • white flowers, dwarf • pale purple flowers, intermediate height
One of the main reasons genes sort independent of one another is that • they produce unrelated traits. • they produce related traits. • they are on the same chromosome. • they are different alleles. • they are on different chromosomes.
A single gene has 3 or more alternative forms. These are called • heterozygotes. • multiple alleles. • homozygotes. • multiple zygotes.
When Mendel crossed two purple-flowered pea plants with each other, he obtained a phenotypic ratio of 3:1 (purple pea plants to white pea plants). What are the parents? • homozygous dominant purple pea plant and homozygous recessive white pea plant • homozygous dominant purple pea plant and heterozygous white pea plant • heterozygous purple pea plant and homozygous dominant purple pea plant • heterozygous purple pea plant and heterozygous purple pea plant
As a genetic counselor, you are constructing a human pedigree for a particular disease. You note that every generation shows the trait, suggesting that it is • sex-linked. • recessive. • dominant. • cannot determine from the information provided.
Gregor Mendel worked with what kind or plant? • Peas • Corn • Wheat • Beans
Each alternative form of a gene for a certain trait is called a(n)? • Genotype • Allele • Phenotype • Recessive trait
A woman who has type B blood marries a man who has type A blood. They have five children, all of which have type AB blood. What are the most probable parental genotypes? • mother IBIB, father IAIA • mother IBi , father IAi • Mother IBIB, father IAi • mother IBi, father IAIA