Unit 10 Biology156
Terms
undefined, object
copy deck
- Which of the following statements is true?
-
D. all of the above
A. Sexual reproduction involves two parents, with each parent supplying a set of genetic information.
B. Sexual reproduction leads to greater genetic variability than does asexual reproduction.
C. Asexual reproduction involves only one parent, and only one set of genetic information. - The structures that contain an organism's DNA are called:
- chromosomes
- Most prokaryotic organisms reproduce mainly by the process of:
- binary fission
- Why is binary fission classified as asexual reproduction?
- because the genetically identical offspring inherit their DNA from a single parent
- During cell division, the DNA is in a coiled up and compacted form called ___. When the cell is not dividing, the DNA is in long thin fibers called ___.
- chromosomes, chromatin
- How many chromosomes are there in typical human body cells?
- 46
- Before a cell can begin dividing by mitosis, it must:
- duplicate all of its chromosomes
- When a chromosome is duplicated, the result is two copies of the chromosome called ___, which are joined together at the ___.
- sister chromatids, centromere
- What is the function of cell division?
-
all of the above
A. to enable a multicellular organism to grow to adult size
B. to replace worn-out or damaged cells
C. to keep the total cell number in a mature organism relatively constant - Approximately how many cells are there in the adult human body?
- 60 trillion
- In which phase do eukaryotic cells spend most of their time?
- interphase
- In which phase are chromosomes duplicated?
- interphase
- In which subphase does DNA replication occur?
- S
- In which phase is the cytoplasm divided in two?
- cytokinesis
- In which phase of mitosis to the chromosomes condense and become visible, and the nuclear envelope breaks into fragments.
- prophase
- In which phase of mitosis are the centromeres of all the chromosomes lined up across the middle of the cell?
- metaphase
- Which of the following occurs during anaphase of mitosis?
-
only B and C are correct
B. sister chromatids separate
C. daughter chromosomes begin to move toward opposite poles of the cell - Which of the following is a feature of plant cell division that distinguishes it from animal cell division?
- a cell plate forms
- Most cells will only divide if they have a solid surface on which to attach and anchor themselves. Why is this beneficial to the organism?
- This prevents cells that become separated from their normal surroundings from dividing inappropriately.
- Animal cells, when growing on a surface in a tissue culture, will multiply to form a single layer, and usually stop dividing when they touch one another. This is called:
- density-dependent inhibition
- What causes density-dependent inhibition?
- when the cells become crowded, the supply of growth factors in the immediate environment is depleted
- Which of the following describes the cell-cycle control system?
- there are checkpoints in the cycle, and the cycle stops unless “go-ahead†signals are applied
- Why do cancer cells divide excessively?
- cancer cells do not have a properly functioning cell-cycle control system
- The spread of cancer cells beyond their original site is called:
- metastasis
- Which of the following is a difference between benign and malignant tumors?
- benign tumors do not metastasize
- Which of the following originate in the external or internal coverings of the body, such as skin or lining of the intestine?
- carcinomas
- Which of the following arise in tissues that support the body, such as bone and muscle?
- sarcomas
- Which of the following are cancers of blood-forming tissues, such as bone marrow, spleen, and lymph nodes?
- leukemias and lymphomas
- Which of the following cancer treatments uses drugs to disrupt cell division?
- chemotherapy
- Which of the following terms describes a “typical†body cell, with the 2n number of chromosomes
- somatic cell
- What are homologous chromosomes?
- chromosomes that carry genes for the same inherited characteristics
- The particular place on a chromosome that contains a particular gene is called the:
- locus
- The 22 pair of chromosomes that do not include the sex chromosomes are called the:
- autosomes
- Two chromosomes in a nucleus that carry loci for the same traits in the same positions on the chromosome, but can specify different versions of the same traits, constitute a pair of:
- homologous chromosomes
- Which of the following describes how we inherit our chromosomes?
- one of each of the homologous chromosomes comes from our father, and the other of each of the homologous chromosomes comes from our mother
- In humans, cells whose nuclei contain two homologous sets of chromosomes are called:
- diploid
- In humans, cells whose nuclei contain only one set of chromosomes are called:
-
both B and C are correct
B. haploid
C. gametes - Egg and sperm cells are called:
- gametes
- A fertilized egg is called:
- zygote
- A zygote is:
- diploid
- Meiosis is the process that:
- produces haploid gametes in diploid organisms
- How does meiosis differ from mitosis?
- In meiosis four daughter cells are produced, while in mitosis two daughter cells are produced.
- Which of the following increases genetic diversity?
-
both A and B are correct
A. independent sorting of homologous chromosomes to daughter cells during meiosis
B. crossing over of corresponding segments between homologous chromosomes - The place where homologous chromatids are attached to each other during crossing-over is called a:
- chiasma
- An orderly picture of magnified images of stained chromosomes is called:
- a karyotype
- How does the karyotype of a human female differ from the karyotype of a human male?
- females have two X chromosomes, and males have X and Y chromosomes
- If a karyotype indicates trisomy 21, which of the following are true?
-
only A and B are correct
A. the person has three copies of chromosome 21 instead of two copies
B. the person has Down syndrome - What is the major factor that increases the risk of having a child with Down syndrome?
- age of the mother, especially if over 35
- The failure of a chromosome pair to separate during meiosis is called
- nondisjunction
- The loss of a fragment from a chromosome is called:
- deletion
- If a fragment of a chromosome joins the homologous chromosome, so that the chromosome now has two copies of that fragment, it is called:
- duplication
- The reattachment of a fragment to the original chromosome, but in the reverse direction, is called:
- inversion
- The attachment of a chromosomal fragment to a nonhomologous chromosome is called:
- translocation