Chapter 13

Question 1

Meiosis

Answer 1

a special type of cell division that produces cells with half the chromosomes of the parent cell.

Only occures in specializd cells like the ovaries and testes

Question 2

How many chromosomes do humans have ?

Answer 2

46

Question 3

Fertilization

Answer 3

unites a sperm and an egg, reestablishing pairs of homologous chromosomes, with both paternal and maternal genes

Question 4

Heredity

Answer 4

The transmission of traits from one generation to the next

Question 5

Variation

Answer 5

Sons and daighters are not idential copies of their parents, there are some differences

Question 6

Genetics

Answer 6

The study of heredity and variation

Question 7

Genes

Answer 7

Coded information in the form of heredity units

Question 8

Gametes

Answer 8

Reproductive cells in plants and animals

Vehicles that transmit genes from one generation to another

Question 9

Somatic cells

Answer 9

All cells of the body except the gametes

Question 10

Locus

Answer 10

A genes specific location along the length of a chromosome

Question 11

Asexual reproduction

Answer 11

a single individual is the sole parent and passes copies of all its genes to its offspring without the fusion of gametes

Virtually exact copies of parent

Question 12

Clone

Answer 12

an individual or group of individuals that are identlical to the parent

Question 13

Sexual reproduction

Answer 13

Two parents give rise to offspring that have unique combinations of genes inherited from two parents

Not exact replica’s but have similar traits

Question 14

Life cycle

Answer 14

the generation to generation sequence of stages in the reproductive history of an organism from conception to production of its own offspring

Question 15

Karyotype

Answer 15

Images of chromosomes are arranged in pairs, starting with longest chromosome

Question 16

Homologous chromosomes or homologs

Answer 16

The two chromosomes of a pair have the same length, centromere position, and staining pattern

Both chromosomes of each pair carry genes controlling the same inherited characters. Example, eye color etc

Question 17

Sex chromosomes

Answer 17

X and Y ..

Females have XX, males have X and Y

Question 18

Autosomes

Answer 18

All other chromosomes that are not X and Y (sex chromosomes)

Question 19

The number of chromosomes in a single set is represented by

Answer 19

(n)

Question 20

Diploid cell

Answer 20

Any cell with two chromosome sets

(2n)

Question 22

Haploid cells

Answer 22

Single set of chromosomes. Gametes contain a single set of chromosomes.

(n)

Question 24

Zygote

Answer 24

Fertilized egg (diploid)

Question 25

Prophase of Meiosis

Answer 25

Spindle formation Nuclear envelope breakdown Chromosomes condense Each chromosome pairs with it homolong / crossing over occurs Each homologou spair has one or more X shaped regions called Chiasmata

Question 26

Crossing over

Answer 26

Chromosome pairs with its homolog and DNA molecules of nonsister chromatids are broken and rejoined

Question 27

Chiasmata

Answer 27

Each homologous pair has one or more X shaped regions where crossovers have occured

Question 28

Metaphase 1 of Meiosis

Answer 28

Pairs of homologous chromosomes are now at metaphase plate Both chromatids are attached to kinetochore microtubules from one pole to the opposite pole

Question 29

Anaphase 1 in Meiosis

Answer 29

Homologs seperate Homologs move toward seperate poles

Question 30

Telophase 1 and Cytokinesis

Answer 30

Each half of the cell has a complete haploid set of duplicated chromosomes. Each chromosome is composed of two sister chromatids forming two haploid daughter cells celavegas furrow forms in animal cells

Question 31

Prophase 11

Answer 31

A spindle apparatus forms Chromosomes move toward metaphase plate

Question 32

Metaphase 11

Answer 32

Chromosomes are positioned at metaphase plate

Question 33

Anaphase 11

Answer 33

chromatids seperate moving towards opposite poles

Question 34

Telophase 11 and cytokinesis

Answer 34

Nuclei form, chromosomes begin decondensing cytokinesis begins one parent cell produces 4 daughter cells

Question 35

Synaptonemal complex

Answer 35

Zipper like structure which holds one homolog tightly to the other

Question 36

Synapsis

Answer 36

the DNA breaks are closed up so that each broken end is joined to the corresponding segment of the nonsister chromatid (parental chromatid is joined to a maternal chromatid)

Question 37

What are the 3 events unique to meosis during meoisis 1

Answer 37

1. Synapsis and crossing over 2. Alignment of homologous pairs at metaphase plate 3. Seperation of homologs

Question 38

Recombiant chromosomes

Answer 38

individuak chromosomes that carry genes from two different parents