Genetic Principles MCQs Flashcards
(26 cards)
What are the primary functions of Mitosis in the body?
a) Production of gametes for sexual reproduction.
b) Reducing the chromosome number by half.
c) Growth, differentiation, and repair, leading to two identical diploid cells.
d) Shuffling the genome to create genetic uniqueness.
e) Formation of four genetically unique haploid cells.
c) Growth, differentiation, and repair, leading to two identical diploid cells.
Which sequence accurately represents the typical order of the Cell Cycle phases, including Interphase?
a) Mitosis, G1, S, G2
b) S, G1, G2, Mitosis
c) G1, S, G2, Mitosis
d) G2, S, G1, Mitosis
e) Interphase, G1, S, G2, Mitosis
c) G1, S, G2, Mitosis
During which phase of Mitosis do chromatin condense into visible chromosomes, and the nuclear envelope begin to dissolve?
a) Metaphase
b) Anaphase
c) Telophase
d) Cytokinesis
e) Prophase
e) Prophase
What is the defining event of Metaphase during Mitosis?
a) Sister chromatids separate and move to opposite poles.
b) The nuclear membrane reforms around the chromosomes.
c) Chromatin condenses into visible chromosomes.
d) Chromosomes are fully condensed and line up on the equator of the cell at the ‘metaphase plate’.
e) The cell divides into two daughter cells.
d) Chromosomes are fully condensed and line up on the equator of the cell at the ‘metaphase plate’.
In which phase of Mitosis do centromeres divide and sister chromatids are pulled to opposite poles by shortening kinetochore fibers?
a) Prophase
b) Metaphase
c) Anaphase
d) Telophase
e) Cytokinesis
c) Anaphase
What key events occur during Telophase in Mitosis?
a) Chromosomes align at the metaphase plate.
b) Nuclear envelope dissolves and spindles attach to centromeres.
c) Sister chromatids reach opposite poles, nuclear membrane reforms, chromosomes decondense, and spindles disassemble.
d) DNA replication takes place.
e) Homologous chromosomes separate.
c) Sister chromatids reach opposite poles, nuclear membrane reforms, chromosomes decondense, and spindles disassemble.
What cellular process involves the division of the cytoplasm, resulting in two separate daughter cells?
a) Karyokinesis
b) Mitosis
c) Interphase
d) Cytokinesis
e) Meiosis
d) Cytokinesis
Which of the following is a key characteristic that distinguishes Meiosis from Mitosis?
a) It occurs throughout the body for growth and repair.
b) DNA content stays the same after cell division.
c) It produces two identical diploid cells.
d) It occurs only in germ (reproductive) cells and results in four genetically unique haploid cells.
e) It involves only one cell division after DNA synthesis.
d) It occurs only in germ (reproductive) cells and results in four genetically unique haploid cells.
Which of the following is a distinguishing feature of Prophase I in Meiosis I?
a) Sister chromatids separate and move to opposite poles.
b) Chromosomes align individually at the equatorial plane.
c) Homologous chromosomes line up side by side in homologous pairs, and crossing over occurs.
d) The nuclear membrane reforms around decondensing chromosomes.
e) The cell undergoes DNA replication.
c) Homologous chromosomes line up side by side in homologous pairs, and crossing over occurs.
During which phase of Meiosis I do homologous chromosomes separate and begin to migrate to opposite poles, while sister chromatids remain together?
a) Prophase I
b) Metaphase I
c) Anaphase I
d) Telophase I
e) Prophase II
c) Anaphase I
Which statement best describes the general nature of Meiosis II?
a) It involves homologous chromosome pairing and crossing over.
b) It is largely identical to a mitotic division, but produces haploid cells.
c) It results in diploid daughter cells identical to the parent cell.
d) It is characterized by the separation of homologous chromosomes.
e) It only occurs in somatic cells.
b) It is largely identical to a mitotic division, but produces haploid cells.
According to Mendel’s First Law of Segregation, what happens to the two copies of each inherited particle from the parents?
a) They fuse together to form a new particle.
b) They remain unaltered, and one is passed on at random in each sperm/egg.
c) They are always expressed equally in the offspring.
d) They disappear after the first generation.
e) They exchange genetic material before being passed on.
b) They remain unaltered, and one is passed on at random in each sperm/egg.
What does Mendel’s Second Law of Independent Assortment state about inherited traits?
a) Traits are always linked and inherited together.
b) Traits are inherited independently of each other.
c) Only dominant traits are inherited.
d) Only recessive traits are inherited.
e) Traits become altered during inheritance.
b) Traits are inherited independently of each other.
What concept is introduced by Mendel’s Third Law of Dominance regarding inherited particles?
a) All inherited particles are equally expressed.
b) Inherited particles can be dominant or recessive, influencing trait expression.
c) Inherited particles always blend together.
d) Inherited particles are only passed on from one parent.
e) The strength of inherited particles determines their expression.
b) Inherited particles can be dominant or recessive, influencing trait expression.
What is the fundamental concept conveyed by Mendel’s Third Law of Dominance?
a) Traits are always inherited in pairs.
b) Inherited particles can be dominant or recessive.
c) All genetic mutations are harmful.
d) Environmental factors solely determine phenotype.
e) Genes are always expressed equally.
b) Inherited particles can be dominant or recessive.
Mendel’s Third Law (Dominance) can be best understood in terms of:
a) Chromosomal crossover rates.
b) The number of chromosomes inherited.
c) The dosage dependence of gene products.
d) The independent assortment of alleles.
e) The segregation of homologous chromosomes.
c) The dosage dependence of gene products.
In a scenario where a phenotype is NOT dosage sensitive, what is the observed phenotypic outcome regarding the number of working alleles?
a) Having one working allele results in a significantly different phenotype than having two.
b) Only two working alleles can produce the full phenotype.
c) There is no difference in phenotype between having one or two “working” alleles.
d) The phenotype is completely absent with only one working allele.
e) The phenotype is severely affected even with one working allele.
c) There is no difference in phenotype between having one or two “working” alleles.
What is typically required for an organism to exhibit a phenotype associated with the complete loss of a gene’s function?
a) Only one copy of a loss-of-function allele.
b) The presence of a gain-of-function allele.
c) Exposure to specific environmental triggers.
d) Two copies of a loss-of-function allele (homozygous recessive).
e) An interaction with a dominant functional allele.
d) Two copies of a loss-of-function allele (homozygous recessive).
Which statement accurately characterizes the general nature of dominant and recessive alleles?
a) Dominant alleles are always loss-of-function, while recessive are always gain-of-function.
b) Dominant alleles tend to be functional (or gain-of-function), and recessive alleles tend to be loss-of-function.
c) Both dominant and recessive alleles are always functional.
d) Dominant alleles are always recessive in heterozygotes.
e) Recessive alleles are only expressed in the presence of a dominant allele.
b) Dominant alleles tend to be functional (or gain-of-function), and recessive alleles tend to be loss-of-function.
Who identified Alkaptonuria as a Mendelian recessive disorder, an event considered the birth of medical genetics?
a) Gregor Mendel
b) Thomas Hunt Morgan
c) James Watson
d) Francis Crick
e) Archibald Garrod
e) Archibald Garrod
Regarding the HGD gene in Alkaptonuria, how many functioning alleles are necessary to prevent the disease phenotype?
a) Zero functioning alleles.
b) One functioning allele.
c) Two functioning alleles.
d) Three functioning alleles.
e) It depends on other genetic factors.
b) One functioning allele.
When does the disease Alkaptonuria typically manifest?
a) When an individual has at least one functional HGD allele.
b) When environmental factors trigger the condition.
c) When both copies of the HGD gene are nonfunctional (homozygous recessive), leading to a blocked biochemical pathway.
d) Only in individuals who are heterozygous for the HGD gene.
e) When there is an accumulation of metabolites in the bloodstream only.
c) When both copies of the HGD gene are nonfunctional (homozygous recessive), leading to a blocked biochemical pathway.
How does a single BRCA1 mutation demonstrate different phenotypic effects depending on what is measured?
a) It always leads to breast cancer, regardless of other factors.
b) It increases breast cancer risk (dominant) but homozygous loss typically causes embryonic lethality (recessive).
c) It only affects males, not females.
d) It causes embryonic lethality in heterozygotes but not in homozygotes.
e) It leads to a gain-of-function mutation in all scenarios.
b) It increases breast cancer risk (dominant) but homozygous loss typically causes embryonic lethality (recessive).
What term describes a genetic scenario where the heterozygous phenotype is an intermediate blend between the two homozygous phenotypes, indicating dosage sensitivity?
a) Codominance
b) Complete dominance
c) Recessiveness
d) Incomplete dominance
e) Epistasis
d) Incomplete dominance
