What Is Life: Biology Chapter 6

Front 1

What is ANAPHASE?

Back 1

The third phase of mitosis, in which the sister chromatids are pulled apart by the spindle fibers, with a full set of chromosomes going to opposite sides of the cell; in meiosis, the homologues separate in anaphase I and the sister chromatids separate in anaphase II

Front 2

What is APOPTOSIS?

Back 2

Programmed cell death, which takes place particularly in parts of the body where the cells are likely to accumulate significant genetic damage over time and are therefore at high risk of becoming cancerous

Front 3

What is ASEXUAL REPRODUCTION?

Back 3

A type of reproduction common in prokaryotes, in which the offspring inherit their DNA from a single parent

Front 4

What is BINARY FISSION?

Back 4

A type of asexual reproduction in which the parent cell divides into two genetically identical daughter cells; bacteria and other prokaryotes reproduce by binary fission

Front 5

What is CANCER?

Back 5

Unrestrained cell growth and division

Front 6

What is a CELL CYCLE?

Back 6

In a cell, the alternation of activities related to cell division and those related to growth and metabolism

Front 7

What is a CENTROMERE?

Back 7

After replication, the region of contact between sister chromatids, which occurs near the center of two strands

Front 8

What is a CHROMATID?

Back 8

One of the two strands of a replicated chromosome

Front 9

What is COMPLEMENTARITY?

Back 9

The characteristic of double-stranded DNA that the base on one strand always has the same pairing partner, or complementary base, on the other strand

Front 10

What is a COMPLEMENTARY BASE

Back 10

A base on a strand of double-stranded DNA that is a pairing partner to a base on the other strand; adenine (A) is the complementary base to thymine (T), and guanine (G) is the complementary base to cytosine (C)

Front 11

What is CROSSING OVER?

Back 11

The exchange of some genetic material between a paternal homologous chromosome and a maternal homologous chromosome, leading to a chromosome carrying genetic material from each

Front 12

What is CYTOKINESIS?

Back 12

In the cell cycle, the stage following mitosis in which cytoplasm and organelles duplicate and are divided into approximately equal parts and the cells separates into two daughters cells; in meiosis, two diploid daughter cells are formed in cytokinesis following telophase I and four haploid daughter cells are formed in cytokinesis following telophase II

Front 13

What is a DAUGHTER CELL?

Back 13

Cells produced by the division of a parent cell

Front 14

What is a DIPLOID?

Back 14

Describes cells that have two copies of each chromosome (in many organisms, including humans, somatic cells are diploid)

Front 15

What is FERTILIZATION?

Back 15

The fusion of two reproductive cells

Front 16

What is a GAMETE?

Back 16

Haploid cells from two individuals that, as sperm and egg, will combine at fertilization to produce offspring; also called reproductive cells

Front 17

What are GONADS?

Back 17

The ovaries and testes in sexually reproducing animals

Front 18

What is a HAPLOID?

Back 18

Describes cells that have a single copy of each chromosome(in many species, including humans, gametes are haploid)

Front 19

What is a HERMAPHRODITE?

Back 19

An organism that produces both male and female gametes [from the names of the greek god Hermes and goddess Aphrodite]

Front 20

What is a HISTONE?

Back 20

Proteins around which the long, linear strands of DNA are wrapped; the histone serve to keep the DNA untangled and to enable an orderly, tight, and efficient packing of the DNA within the cell

Front 21

What is a HOMOLOGOUS PAIR (Homologues)?

Back 21

The maternal and paternal copies of chromosomes

Front 22

What is INTERPHASE?

Back 22

In the cell cycle, the phase during which the cell grows and functions; during the phase, replication of DNA occurs in preparation for cell division

Front 23

What is KARYOTYPE?

Back 23

A visual display of an individual's full set of chromosomes

Front 24

What is MEIOSIS?

Back 24

In sexually reproducing organisms, a process of nuclear division in the gonads that, along with cytokinesis, produces reproductive cells that have half as much genetic material as the parent cell, and that all differ from each other genetically

Front 25

What is METAPHASE?

Back 25

The second phase of mitosis, in which the sister chromatids line up at the center of the cell; in meiosis, the homologues line up at the center of the cell in the metaphase I and the sister chromatids line up in metaphase II

Front 26

What is MITOSIS?

Back 26

The division of a nucleus into two genetically identical nuclei, along with cytokinesis, leads to the formation of two identical daughter cells

Front 27

What is MITOTIC PHASE (M Phase)?

Back 27

The phase of the cell cycle during which first the genetic material and nucleus, and then the rest of the cellular content, divides

Front 28

What is NONDISJUNCTION?

Back 28

The unequal distributions of chromosomes during cell division; can lead to Down syndrome and other disorders caused by the possession in an individual of too few or too many chromosomes

Front 29

What are PARENT CELLS?

Back 29

Cells that divide to form daughter cells, which genetically identical to the parent cell

Front 30

What is a PLACENTA?

Back 30

The organ formed during pregnancy (and expelled at birth) That allows the transfer of gases, nutrients, and waste products between mother and fetus; the placenta is so called from its shape

Front 31

What is PROPHASE?

Back 31

The first phase of mitosis, in which the nuclear membrane breaks down, sister chromatids condense, and the spindle forms; in meiosis, homologous pairs of sister chromatids come together and cross over in prophase I and the chromosomes in daughter cells condense in prophase II

Front 32

What is REPLICATION?

Back 32

The process in both eukaryotes and prokaryotes by which DNA duplicates itself in preparation for cell division

Front 33

What is a REPRODUCTIVE CELL?

Back 33

Haploid cells from two individuals that, as sperm and egg, will combine at fertilization to produce offspring; also called gametes

Front 34

What is SEXUAL REPRODUCTION?

Back 34

A type of reproduction in which offspring are produced by the fusion of gametes from two distinct sexes

Front 35

What is a SISTER CHROMATID?

Back 35

The two identical strands of a replicated chromosome

Front 36

What is a SOMATIC CELL?

Back 36

The (usually diploid) cells of the body of an organism (in contrast to the usually haploid reproductive cells)

Front 37

What is a SPINDLE?

Back 37

A part of the cytoskeleton of a cell, formed in prophase (in mitosis) or in prophase I (in meiosis), from which extend fibers hat organize and separate the sister chromatids

Front 38

What is SPINDLE FIBER?

Back 38

Fibers that extend from one pole of a cell to the other, which the pull the sister chromatids apart in the anaphase stage of mitosis or the anaphase II stage of meiosis

Front 39

What is TELOMERE?

Back 39

A non-coding, highly repetitive section of DNA at the tip of every eukaryotic chromosome that shortens with every cell division; if it becomes too short, additional cell division can cause the loss of functional, essential DNA and therefore almost certain cell death

Front 40

What is TELOPHASE

Back 40

The fourth and last phase of mitosis, in which the chromosomes begin to uncoil and the nuclear membrane is reassembled around them; in meiosis, the sister chromatids arrive at the cell poles and the nuclear membrane reassembles around them in telophase I, and in telophase II the sister chromatids have been pulled apart and the nuclear membrane reassembles around haploid numbers of chromosomes

Front 41

What are X & Y CHROMOSOMES?

Back 41

The human sex chromosomes