Chromosomes Flashcards

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1
Q

Chromosomes form during the _____ of mitosis in the cell cycle.

A

metaphase (M phase)

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2
Q

During _____ phase of the cell cycle, one complete set of DNA moves into one of the two new cells made during _____, and the second complete set moves into the other new cell.

A
  1. M

2. mitosis

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3
Q

The correct movement of the DNA into the two new cells requires that the _____ separate chunks of DNA twist very _____, forming dense _____, which can be seen (when stained) using a standard microscope.

A
  1. 46
  2. tightly
  3. chromosomes
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4
Q

Chromosomes, as _____ structures, have the important job of the precise delivery of DNA to the two new cells.

A

temporary

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5
Q

After DNA _____ has occurred, the visible chromosome now contains _____ the DNA and will split in _____ during _____, allowing one new cell to reeve the left half of the chromosome and the other new cell to receive the right half.

A
  1. replication
  2. twice
  3. half
  4. mitosis
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6
Q

_____ formation begins with the chunk of DNA (after _____) corresponding to the _____ supercoiling itself and becoming a shorter but much _____ structure.

A
  1. Chromosome
  2. chromosome
  3. denser
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7
Q

When DNA _____, it is done in multiple organized steps rather than just as a random tangle.

A

supercoils

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8
Q

As the dsDNA starts to coil more tightly, the tighter structure begins to wind around a set of globular protein balls known as _____, forming a “bead” on the DNA strand.

A

histones

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9
Q

_____ allow the tightly wrapped DNA coil to compact itself without creating tangles or damaging its basic structure.

A

Histones

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10
Q

The thicker beaded groups continue to coil neatly and form the basic structure of the _____.

A

chromosome

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11
Q

During _____ phase of mitosis, each chromosome forms and moves to the center of the cell that is about to divide.

A

M (metaphase)

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12
Q

Just before the cell splits into two cells (_____), each chromosome is pulled apart (_____) so that half of each chromosome goes into one new cell, and the other half goes into the other new cell.

A
  1. cytokinesis

2. nucleokinesis

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13
Q

_____ is the actual number of chromosomes present in a single-cell nucleus at mitosis.

A

Ploidy

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14
Q

Humans have _____ chromosomes divided into _____ pairs.

A
  1. 46

2. 23

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15
Q

A complete set of one of each chromosome is the _____ chromosome number (_____) representing 23 individual chromosomes.

A
  1. haploid

2. 1N

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16
Q

When the nucleus contains both pairs all chromosomes, the number present is the _____ chromosome number (_____).

A
  1. diploid

2. 2N

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17
Q

When additional whole sets of extra chromosomes are present, the condition is termed _____.

A

polyploidy

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18
Q

Polyploidy examples:
69 chromosomes is _____ or _____.
92 chromosomes is _____ or _____.

A
  1. triploidy
  2. 3N
  3. tetraploidy
  4. 4N
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19
Q

Normal human _____ cells are body cells that are not reproductive cells and have a nucleus with a _____ number of chromosomes, _____ pairs.

A
  1. somatic
  2. diploid
  3. 23
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20
Q

Mature human germ line cells are reproductive cells: ova (eggs) and spermatocytes (sperm) each have the _____ number of chromosomes, 23, _____ of each pair.

A
  1. haploid

2. half

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21
Q

When a cell’s nucleus contains the normal diploid number of chromosomes for the species, the cell is termed _____.

A

euploid

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22
Q

When a cell contains more or fewer chromosomes than the normal diploid number for the species, it is termed _____.

A

aneuploid

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23
Q

_____ act as a chromosome cap that holds the DNA strands together similarly to the way a small plastic tube keeps the ends of a shoestring from raveling.

A

Telomeres

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24
Q

The pinched-in area of the chromosome connecting the two sides is the _____.

A

centromere

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25
Q

The _____ also connects the chromosome segments above it and below it.

A

centromere

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26
Q

Each longitudinal left and right half of the chromosome is a _____.

A

chromatid

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27
Q

The two chromatids of a chromosome are known as the _____ chromatids.

A

sister

28
Q

The segments of chromosome extending above the centromere are known as the _____ arms, or the _____ arms.

A
  1. short

2. p

29
Q

The segments of chromosome below the centromere are the _____ arms, or the _____ arms.

A
  1. long

2. q

30
Q

The _____ of a gene on a chromosome is pinpointed using “p” arms and “q” arms.

A

locus

31
Q

The first step in _____ _____ is to count the chromosomes in one cell that is in _____ of mitosis to determine how many chromosomes are present (the normal cell should have _____ chromosomes consisting of _____ pairs).

A
  1. chromosomal
  2. analysis
  3. metaphase
  4. 46
  5. 23
32
Q

After the chromosome number per cell has been established, further analysis requires organizing the chromosomes into a _____.

A

karyotype

33
Q

A _____ is an organized arrangement of all the chromosomes within one cell during the _____ section of mitosis.

A
  1. karyotype

2. metaphase

34
Q

A technician first organizes the chromosomes into _____ and then arranges them by number according to _____ and _____ position.

A
  1. pairs
  2. size
  3. centromere
35
Q

The largest chromosome pair is number _____, and this pair has the _____ nearly in the middle of the chromosomes so that the p arms and q arms are close to the same length.

A
  1. 1

2. centromere

36
Q

When the centromere is close to the center of the chromosome, it is termed a _____ chromosome.

A

metacentric

37
Q

The type of centromere location is termed _____ when the p arms are shorter than the q arms.

A

submetacentric

38
Q

The chromosome pairs continue to be arranged by _____, from the number _____ s to the number _____ s.

A
  1. size
  2. 1
  3. 22
39
Q

When chromosome pairs are nearly the same size, the one with the more _____ centromere has a lower number than the pair (or pairs) of the same size with a _____ centromere.

A
  1. metacentric

2. submetacentric

40
Q

_____ chromosomes have the centromere at the top of the q arms where there is little or no p arm material.

A

Acrocentric

41
Q

The sex chromosomes are positioned _____ in a karyotype even though the X is a medium-sized chromosome.

A

last

42
Q

_____ are the 22 pairs of human chromosomes (numbered 1 through 22) that do not code for the sexual differentiation of a person.

A

Autosomes

43
Q

The 23rd chromosome pair in a karyotype is a _____ chromosome.

A

sex

44
Q

One way to increase the accuracy of chromosomal analysis is by treating the chromosomes with special _____ and _____ so that each pair of chromosomes has a unique and consistent _____ pattern.

A
  1. enzymes
  2. stains
  3. striped
45
Q

The most common way to enhance chromosome appearance is through the _____-banding (_____ banding) process.

A
  1. G

2. Giemsa

46
Q

What is the smallest functional unit of DNA?

A

gene

47
Q

What controls the expression of a specific structure, protein, or function?

A

gene

48
Q

if one gene controls the expression of a trait, it is a _____-gene trait or _____.

A
  1. single

2. monogenic

49
Q

What is an alternative form or variation of a gene at a specific location?

A

allele

50
Q

For each single gene at a specific chromosome location, two _____ together control how that gene is _____.

A
  1. alleles

2. expressed

51
Q

A _____ gene allele is always expressed when it is present.

A

dominant

52
Q

A _____ trait is expressed even when the two gene _____ for that trait are different.

A
  1. dominant

2. alleles

53
Q

When two alleles are different and each is dominant, they are both expressed; the expression is termed _____ because they are expressed _____.

A
  1. codominant

2. equally

54
Q

A _____ trait is a single-gene trait that is expressed only when both gene _____ are the _____.

A
  1. recessive
  2. alleles
  3. same
55
Q

When a recessive gene allele is paired with a dominant allele, the recessive allele is _____ (_____ expressed), and only the dominant allele is expressed.

A
  1. silent

2. not

56
Q

The exact gene allele composition a person has for a specific single-gene trait is the person’s _____ for that trait.

A

genotype

57
Q

The _____ of a trait is the person’s observed expression of any given single-gene trait.

A

phenotype

58
Q

When a person has two identical gene alleles for a single-gene trait, the alleles are termed _____.

A

homozygous

59
Q

When homozygous gene alleles are present for a single-gene trait, the genotype and phenotype for that trait are the _____.

A

same

60
Q

When a person has two different gene alleles for a single-gene trait, the alleles are termed _____.

A

heterozygous

61
Q

For _____ alleles, the actual genotype may be different from the phenotype.

A

heterozygous

62
Q

Normally, recessive single-gene traits are expressed only when the person is _____ for the two gene alleles.

A

homozygous

63
Q

For recessive traits, phenotype and genotype are _____ the _____.

A
  1. always

2. same

64
Q

List at least 5 examples of normal traits for single-gene traits:

A
  1. A, B, O blood groups
  2. Blood-clotting factors (individual)
  3. Color vision (red/green)
  4. Dimples (facial)
  5. Earlobe position
  6. Hair texture
  7. Male pattern baldness
  8. Rh blood groups
  9. Taste discrimination
  10. Tongue rolling
  11. Widow’s peak
65
Q

List at least 5 examples of common single-gene trait disorders:

A
  1. Achondroplasia
  2. Cystic fibrosis
  3. Hemophilia (classic)
  4. Hereditary hemochromatosis
  5. Huntington disease
  6. Hurler syndrome
  7. Marfan syndrome
  8. Muscular dystrophy
  9. Phenylketonuria
  10. Sickle cell trait
  11. Sicke cell disease
  12. Syndactyly
  13. Tay-Sachs disease