All the following statements regarding lethal allele are true except
1. Lethal alleles are always recessive.
2. Lethal alleles may have a late age of onset.
3. Lethal alleles may be caused by mutations in essential genes.
4. Lethal alleles may affect one individual differently than another.

Inactivation of X-chromosome as a part of dosage compensation will be characterized by all the following except
1. The process is entirely random.
2. X inactivation may occasionally occur in males.
3. This process ensures a homogenous phenotype in heterozygotes.
4. X inactivation occurs early in embryonic development.

Gene ‘dosage’ effect can explain all the following except:

1. Males with one normal allele for the X linked gene dystrophin are unaffected, while females (who shut off one of their two X chromosomes) with one normal allele for dystrophin may be mildly affected with muscular dystrophy.

2. Flower color in four-o-clocks seems to be incompletely dominant.

3. In fruit flies, homozygotes for an allele that produces a small amount of functional protein are severely abnormal but survive to adulthood, while homozygotes for an allele that produces no protein at all die as embryos.

4. In bees, males normally are haploid while females normally are diploid.

Resistance to sudden death is a dominant trait in soybeans. Two parent plants that are resistant to sudden death produce a progeny that is not resistant, but this progeny can pass the trait to its progeny in the next generation. This unusual pattern can be explained by?
1. Overdominance
2. Incomplete penetrance
3. Incomplete dominance
4. Variable expressivity

All the following regarding maternal effect genes are true except
1. It is located in the nuclear DNA.
2. Maternal genotype affects offspring phenotype.
3. It may control deposition of material into oocytes.
4. It must be located on the X chromosome.

Which of the following will demonstrate crossing over?
1. A fly that received only y+w+m+ and ywm chromosomes from her parents was able to transmit different combinations of alleles to her offspring.
2. A fly with a gray body and red eyes (wild type) was able to produce offspring with gray bodies and white eyes.
3. True breeding yellow, white, miniature flies always had yellow, white, miniature offspring.
4. None of these examples demonstrate crossing over.

Gross large chromosomal aberrations can be rapidly identified by
1. Karyotype analysis.
2. Genetic studies.
3. Pedigree analysis.
4. DNA fingerprinting

Lateral gene transfer in bacteria is facilitated by direct contact in?
1. Conjugation.
2. Transduction.
3. Transformation.
4. Transfection

In geranium, self-polination of plants with red flowers results in 1/4 red, 2/4 pink and 1/4 white flowered plants. This is most likely due to
1. The soil in which the pink plant was growing was deficient in a critical nutrient.
2. The pink plant had a new mutation, creating an allele to which the wild type "red" is incompletely dominant.
3. The pink plant had a new mutation, creating an allele which is incompletely dominant to red.
4. The pink plant had a new mutation, creating an allele which is codominant to "red".

Eukaryotic genes are split genes with coding and non-coding sequences. A mutation leads to deletion of all coding sequences in a gene. The resultant allele would be called as
1. Lethal
2. Dominant
3. Loss of function
4. Sex-limited