Chapter 6: Chromosomes And Cell Division Flashcards Preview

BIO 111: Introduction To Biology > Chapter 6: Chromosomes And Cell Division > Flashcards

Flashcards in Chapter 6: Chromosomes And Cell Division Deck (64)
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1
Q

Telomere

A

A section of non-coding DNA that serves as a protective cap and is located at each tip of every chromosome

2
Q

Chromatin

A

A linear DNA strand bound to and wrapped tightly around proteins called histones

3
Q

Histones

A

Which keep the DNA from getting tangled and enable it to be tightly and efficiently packed in an orderly manner inside the nucleus

4
Q

Binary Fission

A

Means division in two. Genetic information is carried by a single chromosome that is attached at one site to the cell membrane

5
Q

Replication

A

The method by which a cell creates an exact duplicate of each chromosome

6
Q

Parent Cell

A

The original cell

7
Q

Daughter Cells

A

The parent cell is divided into two new cells which are completely identical

8
Q

Cell Cycle

A

The alternation of activities between processes related to growth and processes related to cell division

9
Q

Somatic Cells

A

Are the cells forming the body of the organism

10
Q

Gametes

A

The sex cells. Sperm and egg cells that give rise to the rest of the cells

11
Q

Interphase

A

Where the cell grows and prepares to divide

12
Q

Mitotic Phase

A

During which first the nucleus and genetic material within the cell divide and then the rest of the cellular contents divide

13
Q

First Step of Interphase: Gap 1

A

A cell may grow and develop as well as performing its various cellular functions. Most cells spend most of their time in Gap 1.

14
Q

Second Step of Interphase: DNA Synthesis

A

The cell begins to prepare for cell division. First, by creating an exact duplicate of each chromosome by replication. After replication each chromosome has a pair of DNA held together near the center

15
Q

Third Step of Interphase: Gap 2

A

Usually characterized by significant growth, as well as high rates of protein synthesis in preparation for division

16
Q

Gap 1 vs Gap 2

A

Gap 2 is different because genetic material has now been duplicated

17
Q

Mitosis

A

A process in which the parent cells nucleus, including its chromosomes divides.

18
Q

Cytokinesis

A

The cytoplasm is divided into two daughter cells which have a complete set of the parents cells DNA and other cellular structures

19
Q

Checkpoints

A

Critical points in the cell cycle at which progress is blocked until specific signals trigger continuation of the process

20
Q

Growth Factors

A

Provide feedback about the cells environment and can signal that division is appropriate

21
Q

First Checkpoint: Assessing DNA Damage and Cell Growth

A

Occurs at the end of Gap 1 when the cell decides if it will proceed to the DNA synthesis phase or delay cell division

22
Q

Checkpoint 2: Assessing DNA Synthesis

A

Is a mitosis readiness assessment that indicates that if no DNA damage is detected and if it passes it initiates the process of mitosis

23
Q

Checkpoint 3: Assessing Anaphase Readiness during Mitosis

A

Assesses whether the chromosomes have aligned properly at the metaphase plate and whether there is appropriate pull on them

24
Q

First Step of Chromosome Replication: Unwinding and Separation

A

The DNA molecule unwinds and separates into two strands.

25
Q

Second Step of Chromosome Replication: Reconstruction and Elongation

A

Each of the single strands becomes a double strand as the appropriate complementary base of a nucleotide pairs with the exposed base

26
Q

Growth in Mitosis

A

Growth happens in part through the creation of new cells.

27
Q

Replacement in Mitosis

A

Cells must be replaced when they die.

28
Q

Apoptosis

A

Some cells need to be replaced in a planned process of cell suicide

29
Q

Sister Chromatids

A

The chromosomes replicate becoming two identical linear DNA molecules

30
Q

Condensation

A

Where the sister chromatids coil tightly and become compact prior to replication

31
Q

Interphase

A

In preparation for mitosis, the chromosome replicates. Where sister chromatids are formed and are held together at the centromere

32
Q

Prophase

A

Following replication, the sister chromatids condense. The spindle forms and the nuclear envelope breaks down

33
Q

Metaphase

A

The chromatids congregate at the cell center. After condensing the sister chromatids line up at the cells center

34
Q

Anaphase

A

The chromatids separate and move in opposite directions. The spindle pulls each chromatid in the sister chromatids pairs toward opposite poles of the cell

35
Q

Telophase

A

New nuclear membranes form around the two complete chromosome sets. The parent cell is prepared to divide into two genetically identical cells

36
Q

Cancer

A

Unrestrained cell growth and division that can damage adjacent tissues.

37
Q

Features of Cancer Cells

A

Cells lose their contact inhibition, cells can divide indefinitely, cells have less adhesiveness

38
Q

Meiosis

A

A process that enables organisms to make special reproductive cells which have only half as many chromosomes as the rest of the cells in the organisms body

39
Q

Diploid

A

Refers to cells that have two copies of each chromosome

40
Q

Haploid

A

Refers to cells that have one copy of each chromosome

41
Q

Outcomes of Meiosis

A

It reduces the amount of genetic material in gametes and produces gametes that differ from one another with respect to the combinations of alleles they carry

42
Q

Homologous Pair

A

A maternal copy and a paternal copy of each of the 22 pairs of chromosomes

43
Q

Interphase in Meiosis

A

In preparation for meiosis, the chromosomes replicate.

44
Q

Prophase I

A

Chromosomes condense and crossing over occurs. The sister chromatids do something that makes every sperm or egg cell genetically unique

45
Q

Crossing Over

A

Some of the genes inherited from your mother get swapped onto the strand of DNA inherited from your father and vice versa

46
Q

Metaphase I

A

All chromosomes line up along the center of the cell. After crossing over each pair of chromosomes move to the center of the cell and are pulled together to form the metaphase plate

47
Q

Anaphase I

A

Homologues are pulled to either side of the cell. One of the two sister chromatids goes to one pole and the other goes to the other pole.

48
Q

Telophase I and Cytokinesis

A

Nuclear membranes reassemble around sets of sister chromatid pairs, and two daughter cells form. Each daughter cell has the genetic material for each of the 23 chromosomes

49
Q

Prophase II

A

Chromosomes recondense. The genetic material in each of the two daughter cells once again could tightly. No crossing over occurs

50
Q

Metaphase II

A

Sister chromatid pairs line up at the center of the cell.

51
Q

Anaphase II

A

Sister chromatids are pulled to opposite sides of the cell. When finished each will become 4 daughter cells

52
Q

Telophase II and Cytokinesis

A

Nuclear membranes reassemble and the two daughter cells pinch into four haploid gametes.

53
Q

Advantages of Sexual Reproduction

A

Combining alleles from two parents at fertilization, crossing over during the production of gametes, and shuffling and reassortment of homologous during meiosis

54
Q

Disadvantages of Sexual Reproduction

A

Dangers of mating, inefficient DNA transfer, and can make organisms vulnerable predation and disease

55
Q

Advantages of Asexual Production

A

Fast and easy, efficient, and genetically identical

56
Q

Disadvantages of Asexual Reproduction

A

The less likely the offspring will be suited to the environment when it changes

57
Q

X and Y Chromosomes

A

Human sex chromosomes

58
Q

Female Sex Determination

A

2 X chromosomes

59
Q

Male Sex Determination

A

One X and One Y chromosome

60
Q

Karyotype

A

A visual display of the complete of chromosomes

61
Q

Turner Syndrome

A

Some females carry only 1 X Chromosome. XO

62
Q

Klinefelter Syndrome

A

An individual who carries 2 X chromosomes and one Y chromosome

63
Q

XYY Males

A

Super males. Relatively tall with severe acne with slightly lower intelligence

64
Q

XXX Females

A

Metafemales. Sterile but no other physical or mental problems