Variation of Traits
Genetic variation increases due to _______ , when pieces of DNA are exchanged on homologous chromosomes.
A) mutations
B) random mating
C) gametes sorting
D) crossing over
Gg is an example of a _______ genotype.
B) homozygous dominant
C) heterozygous
________________ is the most common type of selection, this is when nature selects the most average phenotype. On a graph, it shows the highest point in the middle.
A) disruptive
B) stabilizing
C) directional
Which vocab word describes the genetic material of an individual?
A) phenotype
B) cross over
C) genotype
D) natural selection
______ are different versions of a gene. For example, if the gene is eye color, these may be brown hair, blonde hair, red hair.
A) gametes
B) somatic cells
C) homologous chromosomes
D) alleles
G = gold petals, g = orange petals.
A flower has a genotype of Gg. What is the phenotype of this organism?
A) gold
B) orange
C) heterozygous
D) homozygous recessive
The Galápagos finches have different beak shapes and sizes based on the food sources available. These differences that have occurred over time are an example of _____________.
A) extinction
B) genetic variation
C) traits
D) natural selection
Which vocab word describes the physical appearance of an individual?
A) phenotype
B) cross over
C) genotype
D) natural selection
A characteristic that is only expressed if the homozygous allele is __________, represented by lowercase letters
A) dominant
B) recessive
C) heterozygous
The gene for tallness (T) in a pea plant is dominant over the gene for shortness (t). In a cross between two heterozygous parent pea plants, we can predict that what percentage of the offspring will be short?
MAKE A PUNNETT SQUARE
A) 25%
B) 50%
C) 75%
D) 100%
The mechanism of natural selection primarily works to change which of the following?
A) The distribution of traits in a population over time
B) The genotypes of individual organisms and their expression
C) The rate of mutations resulting from external factors
Which vocab word describes the different version of a gene?
A) chromosome
B) nucleus
C) allele
D) crossing over
A characteristic expressed if the allele is present is a __________ allele, represented by uppercase letters.
A) dominant
B) recessive
C) heterozygous
The ability for people to roll their tongue is dominant to people who cannot. If a tongue roller and a non-tongue roller were crossed, the highest percentage of potential non tongue roller offspring would be which of the following?
Create a Punnett Square.
A) 25%
B) 50%
C) 75%
D) 100%
The frequency of a certain trait in a population will increase over many generations if which of the following is true?
A) The trait is carried by all members of the population, but is expressed only in a few.
B) There is a sudden change in the environment that reduces the population with the trait.
C) Those organisms with the trait have better reproductive success than those without it.
Which vocab word describes a change in the DNA sequence of a chromosome?
A) crossing over
B) RNA
C) mutation
D) meiosis
Meiosis contributes to genetic variation due to which of the following characteristics of the process?
A) The process begins with one diploid cell containing two copies of each chromosome.
B) When homologous chromosomes split, sections of chromosomes can switch places.
C) Gametes that contain double the genetic information are formed.
D) Homologous chromosomes move to opposite sides of the cell to form new nuclei.
Cystic fibrosis is a recessive genetic disorder (f). A man who is a carrier (Ff) and a woman who is also a carrier (Ff) are planning to have a child.
Create a Punnett Square to determine the probability that their child will have cystic fibrosis.
A) 0%
B) 25%
C) 50%
D) 75%
Which of the following statements is NOT true about natural selection and genetic variation?
A) Individual within a species can have genetic variation.
B) Abiotic factors, such as temperature and sunlight, do NOT contribute to the shift in gene frequencies in a population over time.
C) Biotic factors, such as plants and animals, can contribute to changes in gene frequency in a population.
D) An increase in one gene frequency in a population can increase the gene frequency of future generations.
Which of the following best describes the structural relationship between genes, chromosomes, and DNA?
A) Each DNA molecule consists of a number of pairs of genes, and each pair of genes on the DNA molecule is made up of chromosomes.
B) Genes consists of two long strands of chromosomes, and each of these two strands consists of molecules called DNA
C) Each chromosome consists of DNA, and each gene on the chromosome is a particular segment of that DNA.
D) Each chromosome consists of a number of DNA molecules, and each DNA molecule is made up of one to four different genes.