Can You Answer the Correct One from These Biology Cards Flashcards

1) Why did the improvement of microscopy techniques in the late 1800s set the stage for theemergence of modern genetics?A) It revealed new and unanticipated features of Mendel's pea plant varieties.B) It allowed the study of meiosis and mitosis, revealing parallels between behaviors of genesand chromosomes.C) It allowed scientists to see the DNA present within chromosomes.D) It led to the discovery of mitochondria.E) It showed genes functioning to direct the formation of enzymes.

2) When Thomas Hunt Morgan crossed his red-eyed F1 generation flies to each other, the F2generation included both red- and white-eyed flies. Remarkably, all the white-eyed flies weremale. What was the explanation for this result?A) The gene involved is on the X chromosome.B) The gene involved is on the Y chromosome.C) The gene involved is on an autosome.D) Other male-specific factors influence eye color in flies.E) Other female-specific factors influence eye color in flies.

3) Morgan and his colleagues worked out a set of symbols to represent fly genotypes. Which ofthe following are representative?A) AaBb _ AaBbB) 46, XY or 46, XXC) vg+vgse+se _ vgvgseseD) +2 _ +3

4) Sturtevant provided genetic evidence for the existence of four pairs of chromosomes inDrosophila in which of these ways?A) There are four major functional classes of genes in Drosophila.B) Drosophila genes cluster into four distinct groups of linked genes.C) The overall number of genes in Drosophila is a multiple of four.D) The entire Drosophila genome has approximately 400 map units.E) Drosophila genes have, on average, four different alleles.

5) A man with Klinefelter syndrome (47, XXY) is expected to have any of the followingEXCEPTA) lower sperm count.B) possible breast enlargement.C) increased testosterone.D) long limbs.E) female body characteristics.

6) A woman is found to have 47 chromosomes, including 3 X chromosomes. Which of thefollowing describes her expected phenotype?A) Masculine characteristics such as facial hairB) Enlarged genital structuresC) Excessive emotional instabilityD) Normal femaleE) Sterile female

7) Males are more often affected by sex-linked traits than females becauseA) males are hemizygous for the X chromosome.B) male hormones such as testosterone often alter the effects of mutations on the X chromosome.C) female hormones such as estrogen often compensate for the effects of mutations on the X.D) X chromosomes in males generally have more mutations than X chromosomes in females.E) mutations on the Y chromosome often worsen the effects of X-linked mutations.

8) What is the chromosomal system for determining sex in mammals?A) Haploid-diploidB) X-0C) X-XD) X-YE) Z-W

9) What is the chromosomal system for sex determination in birds?A) Haploid-diploidB) X-0C) X-XD) X-YE) Z-W

10) What is the chromosomal system of sex determination in most species of ants and bees?A) Haploid-diploidB) X-0C) X-XD) X-YE) Z-W

11) SRY is best described in which of the following ways?A) A gene region present on the Y chromosome that triggers male developmentB) A gene present on the X chromosome that triggers female developmentC) An autosomal gene that is required for the expression of genes on the Y chromosomeD) An autosomal gene that is required for the expression of genes on the X chromosomeE) Required for development, and males or females lacking the gene do not survive past earlychildhood

12) In cats, black fur color is caused by an X-linked allele; the other allele at this locus causesorange color. The heterozygote is tortoiseshell. What kinds of offspring would you expect fromthe cross of a black female and an orange male?A) Tortoiseshell females; tortoiseshell malesB) Black females; orange malesC) Orange females; orange malesD) Tortoiseshell females; black malesE) Orange females; black males

13) Red-green color blindness is a sex-linked recessive trait in humans. Two people with normalcolor vision have a color-blind son. What are the genotypes of the parents?A) XcXc and XcYB) XcXc and XCYC) XCXC and XcYD) XCXC and XCYE) XCXc and XCY

14) Cinnabar eyes is a sex-linked recessive characteristic in fruit flies. If a female havingcinnabar eyes is crossed with a wild-type male, what percentage of the F1 males will havecinnabar eyes?A) 0%B) 25%C) 50%D) 75%E) 100%

15) Calico cats are female becauseA) a male inherits only one of the two X-linked genes controlling hair color.B) the males die during embryonic development.C) the Y chromosome has a gene blocking orange coloration.D) only females can have Barr bodies.E) multiple crossovers on the Y chromosome prevent orange pigment production.