Unit 10 Biology156

Front 1

Which of the following statements is true?

Back 1

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.

Front 2

The structures that contain an organism's DNA are called:

Back 2

chromosomes

Front 3

Most prokaryotic organisms reproduce mainly by the process of:

Back 3

binary fission

Front 4

Why is binary fission classified as asexual reproduction?

Back 4

because the genetically identical offspring inherit their DNA from a single parent

Front 5

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 ___.

Back 5

chromosomes, chromatin

Front 6

How many chromosomes are there in typical human body cells?

Back 6

46

Front 7

Before a cell can begin dividing by mitosis, it must:

Back 7

duplicate all of its chromosomes

Front 8

When a chromosome is duplicated, the result is two copies of the chromosome called ___, which are joined together at the ___.

Back 8

sister chromatids, centromere

Front 9

What is the function of cell division?

Back 9

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

Front 10

Approximately how many cells are there in the adult human body?

Back 10

60 trillion

Front 11

In which phase do eukaryotic cells spend most of their time?

Back 11

interphase

Front 12

In which phase are chromosomes duplicated?

Back 12

interphase

Front 13

In which subphase does DNA replication occur?

Back 13

S

Front 14

In which phase is the cytoplasm divided in two?

Back 14

cytokinesis

Front 15

In which phase of mitosis to the chromosomes condense and become visible, and the nuclear envelope breaks into fragments.

Back 15

prophase

Front 16

In which phase of mitosis are the centromeres of all the chromosomes lined up across the middle of the cell?

Back 16

metaphase

Front 17

Which of the following occurs during anaphase of mitosis?

Back 17

only B and C are correct
B. sister chromatids separate
C. daughter chromosomes begin to move toward opposite poles of the cell

Front 18

Which of the following is a feature of plant cell division that distinguishes it from animal cell division?

Back 18

a cell plate forms

Front 19

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?

Back 19

This prevents cells that become separated from their normal surroundings from dividing inappropriately.

Front 20

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:

Back 20

density-dependent inhibition

Front 21

What causes density-dependent inhibition?

Back 21

when the cells become crowded, the supply of growth factors in the immediate environment is depleted

Front 22

Which of the following describes the cell-cycle control system?

Back 22

there are checkpoints in the cycle, and the cycle stops unless “go-ahead” signals are applied

Front 23

Why do cancer cells divide excessively?

Back 23

cancer cells do not have a properly functioning cell-cycle control system

Front 24

The spread of cancer cells beyond their original site is called:

Back 24

metastasis

Front 25

Which of the following is a difference between benign and malignant tumors?

Back 25

benign tumors do not metastasize

Front 26

Which of the following originate in the external or internal coverings of the body, such as skin or lining of the intestine?

Back 26

carcinomas

Front 27

Which of the following arise in tissues that support the body, such as bone and muscle?

Back 27

sarcomas

Front 28

Which of the following are cancers of blood-forming tissues, such as bone marrow, spleen, and lymph nodes?

Back 28

leukemias and lymphomas

Front 29

Which of the following cancer treatments uses drugs to disrupt cell division?

Back 29

chemotherapy

Front 30

Which of the following terms describes a “typical” body cell, with the 2n number of chromosomes

Back 30

somatic cell

Front 31

What are homologous chromosomes?

Back 31

chromosomes that carry genes for the same inherited characteristics

Front 32

The particular place on a chromosome that contains a particular gene is called the:

Back 32

locus

Front 33

The 22 pair of chromosomes that do not include the sex chromosomes are called the:

Back 33

autosomes

Front 34

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:

Back 34

homologous chromosomes

Front 35

Which of the following describes how we inherit our chromosomes?

Back 35

one of each of the homologous chromosomes comes from our father, and the other of each of the homologous chromosomes comes from our mother

Front 36

In humans, cells whose nuclei contain two homologous sets of chromosomes are called:

Back 36

diploid

Front 37

In humans, cells whose nuclei contain only one set of chromosomes are called:

Back 37

both B and C are correct
B. haploid
C. gametes

Front 38

Egg and sperm cells are called:

Back 38

gametes

Front 39

A fertilized egg is called:

Back 39

zygote

Front 40

A zygote is:

Back 40

diploid

Front 41

Meiosis is the process that:

Back 41

produces haploid gametes in diploid organisms

Front 42

How does meiosis differ from mitosis?

Back 42

In meiosis four daughter cells are produced, while in mitosis two daughter cells are produced.

Front 43

Which of the following increases genetic diversity?

Back 43

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

Front 44

The place where homologous chromatids are attached to each other during crossing-over is called a:

Back 44

chiasma

Front 45

An orderly picture of magnified images of stained chromosomes is called:

Back 45

a karyotype

Front 46

How does the karyotype of a human female differ from the karyotype of a human male?

Back 46

females have two X chromosomes, and males have X and Y chromosomes

Front 47

If a karyotype indicates trisomy 21, which of the following are true?

Back 47

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

Front 48

What is the major factor that increases the risk of having a child with Down syndrome?

Back 48

age of the mother, especially if over 35

Front 49

The failure of a chromosome pair to separate during meiosis is called

Back 49

nondisjunction

Front 50

The loss of a fragment from a chromosome is called:

Back 50

deletion

Front 51

If a fragment of a chromosome joins the homologous chromosome, so that the chromosome now has two copies of that fragment, it is called:

Back 51

duplication

Front 52

The reattachment of a fragment to the original chromosome, but in the reverse direction, is called:

Back 52

inversion

Front 53

The attachment of a chromosomal fragment to a nonhomologous chromosome is called:

Back 53

translocation