Bio unit 5

These cells are the result of nondisjunction during which of the following phases?

Meiosis I

Which of the following occurs in all species of living organisms and may lead to an increase in genetic variation?

Mutations in the genome

In the pedigree above, squares represent males and circles represent females. Individuals who express a particular trait are represented by shaded figures. Which of the following patterns of inheritance best explains the transmission of the trait?

Autosomal dominant

In humans, red-green color blindness is a sex-linked recessive trait. If a man and a woman produce a color-blind son, which of the following must be true?

Both parents carry the allele for color blindness.

Butterflies of the genus Colias live in the Rocky Mountains, where they experience a wide range of temperatures. Different variants of a particular glycolytic enzyme in the flight muscles are optimally active at different temperatures. Within the same population, some individual butterflies fly most effectively at 29°C , while others fly most effectively at 40°C. Still others can be equally active at both temperatures. Which of the following claims is most consistent with the observed butterfly behavior?

Butterflies that express two variants of the enzyme are active over a greater range of temperature.

The diagram above illustrates which of the following processes?

Crossing over

The process depicted in the image above is best summarized by which of the following descriptions?

During meiosis, crossing over leads to recombination of alleles between homologous chromosomes.

The events listed below generally take place during meiosis. I. Synapsis occurs.II. Crossing-over is completed. III. Condensation of chromosomes begins .IV. Separation of homologous chromosomes begins. Which of the following is the correct sequence of these events?

III, I, II, IV

Which of the following correctly describes the relationship of the dark-coat-color allele to the albino condition?

It is dominant.

All of the following are true statements about meiosis in mammals EXCEPT:

It produces four genetically identical gametes.

Which of the following occurs during mitosis but not during meiosis I ?

The chromatids of each chromosome are separated.

Humans have a diploid number (2n) of 46. Which of the following statements best predicts the consequence if meiosis did not occur during gametogenesis?

The chromosome number would double with each generation.

Which of the following best supports the hypothesis that the difference in leaf color is genetically controlled?

The existence of yellow-leaved seedlings as well as green-leaved ones on day 14 in dish B

In peas the trait for tall plants is dominant (T) and the trait for short plants is recessive (t). The trait for yellow seed color is dominant (Y) and the trait for green seed color is recessive (y). A cross between two plants results in 296 tall yellow plants and 104 tall green plants. Which of the following are most likely to be the genotypes of the parents?

TtYy x TtYy

A genetic counselor is consulted by a young man who is worried about developing Huntington's disease, an inherited disorder caused by a dominant allele of a single gene. The young man explains that his cousin was recently diagnosed with Huntington's disease, and the news has caused him to consider his own risk of developing the disorder. Which of the following questions will best help the genetic counselor to evaluate the risk of the young man developing Huntington's disease and transmitting it to his children?

Were your parents or grandparents ever diagnosed with Huntington's disease?

Which of the following questions will best help a researcher design an experiment to learn about the relationship between hydrangea flower color, aluminum, and pH?

What will be the flower color of hydrangeas grown in soils of varying pH with or without aluminum?

If in the F1 and F2 generations the same characteristics appeared in both males and females, it would be safe to assume that these traits for eye color and wing length

are autosomal characteristics

The pedigree suggests that the gene is on a nuclear chromosome, and not on mitochondrial DNA, because

maternal mitochondrial mutations are inherited by all of a mother's offspring