Science chapter 6

Question 1

Anaphase

Answer 1

the stage of meiotic or mitotic cell division in which the chromosomes move away from one another to opposite poles of the spindle.

Question 2

Binary fission

Answer 2

Binary fission (“division in half”) is a kind of asexual reproduction. It is the most common form of reproduction in prokaryotes and occurs in some single-celled eukaryotes.

Question 3

Cell cycle

Answer 3

The cell cycle or cell-division cycle is the series of events that take place in a cell leading to its division and duplication of its DNA (DNA replication) to produce two daughter cells.

Question 4

Cell division

Answer 4

The mitosis division process has several steps or phases of the cell cycle—interphase, prophase, prometaphase, metaphase, anaphase, telophase, and cytokinesis—to successfully make the new diploid cells

Question 5

Chromosome definition

Answer 5

a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes

Question 6

Cytokinesis

Answer 6

the cytoplasmic division of a cell at the end of mitosis or meiosis, bringing about the separation into two daughter cells.

Question 7

DNA

Answer 7

deoxyribonucleic acid, a self-replicating material present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.

Question 8

DNA replication

Answer 8

DNA replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules

Question 9

Interphase

Answer 9

the resting phase between successive mitotic divisions of a cell, or between the first and second divisions of meiosis

Question 10

Metaphase

Answer 10

the second stage of cell division, between prophase and anaphase, during which the chromosomes become attached to the spindle fibers.

Question 11

Mitosis

Answer 11

a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth.

Question 12

Prophase

Answer 12

the first stage of cell division, before metaphase, during which the chromosomes become visible as paired chromatids and the nuclear envelope disappears. The first prophase of meiosis includes the reduction division.

Question 13

Telophase

Answer 13

the final phase of cell division, between anaphase and interphase, in which the chromatids or chromosomes move to opposite ends of the cell and two nuclei are formed.

Question 14

Asexual reproduction

Answer 14

Asexual reproduction is a type of reproduction by which offspring arise from a single organism, and inherit the genes of that parent only; it does not involve the fusion of gametes, and almost never changes the number of chromosomes.

Question 15

Diploid

Answer 15

containing two complete sets of chromosomes, one from each parent

Question 16

Egg

Answer 16

An organic vessel where an embryo develops, and one in which the female of an animal species lay as a means of reproduction

Question 17

Fertilization

Answer 17

the action or process of fertilizing an egg, female animal, or plant, involving the fusion of male and female gametes to form a zygote

Question 18

Gamete

Answer 18

a mature haploid male or female germ cell that is able to unite with another of the opposite sex in sexual reproduction to form a zygote.

Question 19

Haploid

Answer 19

having a single set of unpaired chromosomes

Question 20

Homologous chromosomes

Answer 20

The cell has two sets of each chromosome; one of the pair is derived from the mother and the other from the father. The maternal and paternal chromosomes in a homologous pair have the same genes at the same loci, but possibly different alleles

Question 21

Meiosis

Answer 21

a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores.

Question 22

Sexual reproduction

Answer 22

the production of new living organisms by combining genetic information from two individuals of different types (sexes). In most higher organisms, one sex (male) produces a small motile gamete that travels to fuse with a larger stationary gamete produced by the other (female).

Question 23

Sperm

Answer 23

The male gamete or reproductive cell involved in sexual reproduction. It is produced by a male organism that unites with the egg of a female organism forming a zygote.Nov 19, 2008

Question 24

Zygote

Answer 24

a diploid cell resulting from the fusion of two haploid gametes; a fertilized ovum.

Question 25

Codon

Answer 25

a sequence of three nucleotides that together form a unit of genetic code in a DNA or RNA molecule.

Question 26

Genetic code

Answer 26

the nucleotide triplets of DNA and RNA molecules that carry genetic information in living cells.

Question 27

Mutagen

Answer 27

an agent, such as radiation or a chemical substance, that causes genetic mutation.

Question 28

Mutation

Answer 28

A Mutation occurs when a DNA gene is damaged or changed in such a way as to alter the genetic message carried by that gene. A Mutagen is an agent of substance that can bring about a permanent alteration to the physical composition of a DNA gene such that the genetic message is changed.

Question 29

Protein synthesis

Answer 29

the process by which amino acids are linearly arranged into proteins through the involvement of ribosomal RNA, transfer RNA, messenger RNA, and various enzymes.

Question 30

RNA

Answer 30

ribonucleic acid, a nucleic acid present in all living cells. Its principal role is to act as a messenger carrying instructions from DNA for controlling the synthesis of proteins, although in some viruses RNA rather than DNA carries the genetic information

Question 31

Transcription

Answer 31

Transcription is the process by which the information in a strand of DNA is copied into a new molecule of messenger RNA

Question 32

Translation

Answer 32

translation is the process in which ribosomes in a cell’s cytoplasm create proteins, following transcription of DNA to RNA in the cell’s nucleus.