The Physical Basis of Heredity Practice Test (page 2)
Review the following concepts if needed:
- Genetics, Cells, and Mendel's Law for Genetics
- Chromosomes for Genetics
- Cell Division and Reproduction for Genetics
- Gametogenesis for Genetics
The Physical Basis of Heredity Practice Test
Choose the one best match for each organelle (in the left column) with its function or description (in the right column). No organelle has more than one match.
|Cell Organelle||Function or Description|
|1. Mitochondria||A. Establishes polar region|
|2. Centrioles||B. May contain a photosynthetic system|
|3. Chromosome||C. Site of protein synthesis|
|4. Nucleus||D. Location of genes|
|5. Nucleolus||E. Organelle involved in protein modification and subcellular localization|
|6. Ribosome||F. Storage of excess water and other metabolic products|
|7. Endoplasmic reticulum||G. Site of major ATP synthesis|
|8. Plastid||H. Organelle containing linear chromosomes|
|9. Golgi body||I. Cytoplasmic membrane network|
|10. Vacuole||J. RNA-rich region in nucleus|
For each of the following definitions, give the appropriate term. Terms are single words unless indicated otherwise.
- Any chromosome other than a sex chromosome.
- Site on a chromosome to which spindle fibers attach.
- Adjective applicable to a chromosome with arms of about equal length.
- Adjective referring to the number of chromosomes in a gamete
- Specialized cell division process consisting of a reductional and an equational division.
- Division of the cytoplasm.
- The first phase of mitosis.
- The cytological structure on paired chromosomes with which genetic exchange (crossing over) is correlated.
- Chromosomes that contain enough similar genetic material to pair in meiosis.
- The period between mitotic division cycles.
Choose the single most appropriate answer.
- An organelle present in animal cells but missing from plant cells is (a) a nucleolus (b) a centriole (c) a vacuole (d) a mitochondrion (e) more than one of the above
- During the meiosis I division, chromosomes divide (a) equationally (b) reductionally.
- Humans normally have 46 chromosomes in skin cells. How many autosomes would be expected in a kidney cell? (a) 46 (b) 23 (c) 47 (d) 44 (e) none of the above
- During mitosis, synapsis occurs in the phase called (a) telophase (b) anaphase (c) prophase (d) metaphase (e) none of the above
- If the genetic endowments of two nuclei that unite to produce the plant zygote are labeled A and B, and the other product of fertilization within that same embryo sac is labeled ABB, then the tube nucleus that was in the pollen tube that delivered the fertilizing male gametes must be labeled (a) A (b) AB (c) B (d) BB (e) none of the above
- A locus is best defined as (a) an alternative form of a gene (b) the position of a gene on a chromosome (c) a cellular structure composed of DNA and protein (d) a fertilized egg (e) the place on a chromosome where spindle fibers attach
- The different forms of a gene are called (a) gametes (b) loci (c) homologues (d) alleles (e) ribosomes
- Which of the following cells is normally diploid? (a) primary polar body (b) spermatid (c) primary spermatocyte (d) spermatozoan (e) secondary polar body
- Upon which two major features of chromosomes does their cytological identification depend? (a) length of chromosome and position of centromere (b) amount of DNA and intensity of staining (c) numbers of nucleoli and centromeres (d) number of chromatids and length of arms (e) chromosome thickness and length
- In oogenesis, the cell that corresponds to a spermatid is called a(an) (a) ovum (b) egg (c) secondary oocyte (d) oogonium (e) secondary polar body
- There are 40 chromosomes in somatic cells of the house mouse. (a) How many chromosomes does a mouse receive from its father? (b) Howmany autosomes are present in a mouse gamete? (c) Howmany sex chromosomes are there in a mouse ovum? (d) How many autosomes are there in somatic cells of a female?
- Identify the mitotic stage represented in each of the following diagrams of isolated cells from an individual with a diploid chromosome complement of one metacentric pair and one acrocentric pair of chromosomes.
- Identify the meiotic stage represented in each of the following diagrams of isolated cells from the germ line of an individual with one acrocentric pair and one metacentric pair of chromosomes.
- How many different types of gametic chromosomal combinations (paternal vs. maternal) can be formed in the garden pea (2n = 14)? (Hint: See Solved Problem 1.1.)
- What animal cells correspond to the three megaspores that degenerate following meiosis in plants?
- What plant cell corresponds functionally to the primary spermatocyte?
- What is the probability of a sperm cell of a man (n = 23) containing only replicas of the centromeres that were received from his mother? (Hint: See Solved Problem 1.1.)
- How many chromosomes of humans (2n = 46) will be found in (a) a secondary spermatocyte, (b) a spermatid, (c) a spermatozoan, (d) a spermatogonium, (e) a primary spermatocyte?
- Howmany human egg cells (ova) are produced by (a) an oogonium, (b) a primary oocyte, (c) an ootid, (d) a polar body?
- Corn (Zea mays) has a diploid number of 20. How many chromosomes would be expected in (a) a meiotic product (microspore or megaspore), (b) the cell resulting from the first nuclear division (karyokinesis) of a megaspore, (c) a polar nucleus, (d) a sperm nucleus, (e) a microspore mother cell, (f) a leaf cell, (g) a mature embryo sac (after degeneration of nonfunctional nuclei), (h) an egg nucleus, (i) an endosperm cell, (j) a cell of the embryo, (k) a cell of the pericarp, (l) an aleurone cell?
- A pollen grain of corn with nuclei labeled A, B, and C fertilized an embryo sac with nuclei labeled D, E, F, G, H, I, J, and K as shown below.
- Which of the following five combinations could be found in the embryo: (1) ABC (2) BCI (3) GHC (4) AI (5) CI?
- Which of the above five combinations could be found in the aleurone layer of the seed?
- Which of the above five combinations could be found in the germinating pollen tube?
- Which of the nuclei, if any, in the pollen grain would contain genetically identical sets of chromosomes?
- Which of the nuclei in the embryo sac would be chromosomally and genetically equivalent?
- Which of the nuclei in these two gametophytes will have no descendants in the mature seed?
- A certain plant has eight chromosomes in its root cells: a long metacentric pair, a short metacentric pair, a long telocentric pair, and a short telocentric pair. If this plant fertilizes itself (self-pollination), what proportion of the offspring would be expected to have (a) four pairs of telocentric chromosomes, (b) one telocentric pair and three metacentric pairs of chromosomes, (c) two metacentric and two telocentric pairs of chromosomes?
- Oogenesis: (a) first metaphase; (b) first telophase resulting from part (a); (c) second metaphase resulting from part (b); (d) second telophase resulting from part (c).
- Spermatogenesis: (a) anaphase of a dividing spermatogonium, (b) anaphase of a dividing primary spermatocyte, (c) anaphase of a secondary spermatocyte derived from part (b), (d) four sperm cells resulting from part (b).
For Problems 1.17 and 1.18, diagram the designated stages of gametogenesis in a diploid organism that has one pair of metacentric and one pair of acrocentric chromosomes. Label each of the chromatids assuming that the locus of gene A is on the metacentric pair (one of which carries the A allele and its homologue carries the a allele) and that the locus of gene B is on the acrocentric chromosome pair (one of which carries the B allele and its homologue carries the b allele).