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This article discusses the process of meiosis in sexually reproducing organisms, which allows for the creation of gametes with half the number of chromosomes of body cells. It also explores various topics related to reproduction and genetic traits.
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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
