Lecture 13

Question 1

asexual reproduction

Answer 1

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

Question 2

autosome

Answer 2

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

Question 3

chiasmata

Answer 3

The X-shaped, microscopically
visible region where crossing over has
occurred earlier in prophase I between homologous
nonsister chromatids. Chiasmata
become visible after synapsis ends, with the
two homologs remaining associated due to
sister chromatid cohesion.

Question 4

crossing over

Answer 4

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

Question 5

diploid cell

Answer 5

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

Question 6

fertilization

Answer 6

The union of haploid gametes

to produce a diploid zygote.

Question 7

gamete

Answer 7

Sex Cell

Question 8

gene

Answer 8

A Section of DNA

Question 9

haploid cell

Answer 9

Cell containing one set of chromosomes

Question 10

heredity

Answer 10

The transmission of traits from one

generation to the next.

Question 11

homologous chromosome

Answer 11

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.

Question 12

karyotype

Answer 12

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

Question 13

life cycle

Answer 13

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

Question 14

locus

Answer 14

A specific
place along the length of a chromosome
where a given gene is located.

Question 15

meiosis

Answer 15

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.

Question 16

meiosis I

Answer 16

The first division of a two-stage process
of cell division in sexually reproducing
organisms that results in cells with half the
number of chromosome sets as the original
cell.

Question 17

meiosis II

Answer 17

The second division of a two-stage
process of cell division in sexually reproducing
organisms that results in cells with
half the number of chromosome sets as the
original cell.

Question 18

recombinant chromosomes

Answer 18

crossing over produces recombinant chromosomes which combine genes inherited from each parent

Question 19

sex chromosomes

Answer 19

x and y chromosome. Determines gender

Question 20

sexual reproduction

Answer 20

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

Question 21

somatic cell

Answer 21

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

Question 22

tetrad

Answer 22

A protein holds homologous chromosomes together tightly

Now they are called a tetrad

Question 23

variation

Answer 23

Differences between members of

the same species.

Question 24

zygote

Answer 24

The diploid cell produced by
the union of haploid gametes during fertilization;
a fertilized egg.