Chapter 13

Question 1

A chromosome created when crossing over combines the DNA from two parents into a single chromosome.

Answer 1

Recombinant Chromosome

Question 2

The X-shaped, microscopically visible region where homologous nonsister chromatids have exchanged genetic material through crossing over during meiosis, the two homologs remaining associated due to sister chromatid cohesion.

Answer 2

Chiasma

Question 3

The reciprocal exchange of genetic material between nonsister chromatids during prophase I of meiosis.

Answer 3

Crossing Over

Question 4

The pairing and physical connection of replicated homologous chromosomes during prophase I of meiosis.

Answer 4

Synapsis

Question 5

(1) In the life cycle of a plant or alga undergoing alternation of generations, a haploid cell produced in the sporophyte by meiosis. A _____ can divide by mitosis to develop into a multicellular haploid individual, the gametophyte, without fusing with another cell. (2) In fungi, a haploid cell, produced either sexually or asexually, that produces a mycelium after germination.

Answer 5

Spore

Question 6

In organisms (plants and some algae) that have alternation of generations, the multicellular diploid form that results from the union of gametes. The ________ produces haploid spores by meiosis that develop into gametophytes.

Answer 6

Sporophyte

Question 7

In organisms (plants and some algae) that have alternation of generations, the multicellular haploid form that produces haploid gametes by mitosis. The haploid gametes unite and develop into sporophytes.

Answer 7

Gametophyte

Question 8

A life cycle in which there is both a multicellular diploid form, the sporophyte, and a multicellular haploid form, the gametophyte; characteristic of plants and some algae.

Answer 8

Alternation of Generations

Question 9

A modified type of cell division in sexually reproducing organisms consisting of two rounds of cell division but only one round of DNA replication. It results in cells with half the number of chromosome sets as the original cell.

Answer 9

Meiosis

Question 10

The diploid product of the union of haploid gametes during fertilization; a fertilized egg.

Answer 10

Zygote

Question 11

(1) The union of haploid gametes to produce a diploid zygote. (2) The addition of mineral nutrients to the soil.

Answer 11

Fertilization

Question 12

A cell containing only one set of chromosomes (n).

Answer 12

Haploid Cell

Question 13

A cell containing two sets of chromosomes (2n), one set inherited from each parent.

Answer 13

Diploid Cell

Question 14

A chromosome that is not directly involved in determining sex; not a sex chromosome.

Answer 14

Autosome

Question 15

A chromosome responsible for determining the sex of an individual.

Answer 15

Sex Chromosome

Question 16

A pair of chromosomes of the same length, centromere position, and staining pattern that possess genes for the same characters at corresponding loci. One homologous chromosome is inherited from the organism’s father, the other from the mother. Also called homologs, or a homologous pair.

Answer 16

Homologous Chromosomes

Question 17

A display of the chromosome pairs of a cell arranged by size and shape.

Answer 17

Karyotype

Question 18

Any cell in a multicellular organism except a sperm or egg.

Answer 18

Somatic Cell

Question 19

The generation-to-generation sequence of stages in the reproductive history of an organism.

Answer 19

Life Cycle

Question 20

(1) A lineage of genetically identical individuals or cells. (2) In popular usage, a single individual organism that is genetically identical to another individual. (3) As a verb, to make one or more genetic replicas of an individual or cell.

Answer 20

Clone

Question 21

A type of reproduction in which two parents give rise to offspring that have unique combinations of genes inherited from the gametes of the parents.

Answer 21

Sexual Reproduction

Question 22

The generation of offspring from a single parent that occurs without the fusion of gametes (by budding, division of a single cell, or division of the entire organism into two or more parts). In most cases, the offspring are genetically identical to the parent.

Answer 22

Asexual Reproduction

Question 23

A haploid reproductive cell, such as an egg or sperm. ______ unite during sexual reproduction to produce a diploid zygote.

Answer 23

Gamete

Question 24

A discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA, for some viruses).

Answer 24

Gene

Question 25

The scientific study of heredity and hereditary variation.

Answer 25

Genetics

Question 26

The transmission of traits from one generation to the next.

Answer 26

Heredity