Chapter 13

Question 1

Heredity

Answer 1

Transmission of trait from one generation to the next is called inheritance or heredity

Question 2

Variation

Answer 2

Differences among individual

Question 3

Genetics

Answer 3

Is the scientific study of heredity and heredity variation

Question 4

Genes

Answer 4

Parents endow their offspring with coded information in the form heredity called gene

Question 5

Gametes

Answer 5

Reproductive cell

Question 6

Locus

Answer 6

A genes specific location along the length of chromosomes is called the gene locus

Question 7

Asexual reproduction

Answer 7

A single individual is the sole parent and passes copies of its gene to it’s offspring. Identical offspring

Question 8

Clone

Answer 8

A group of genetically identical individual

Question 9

Sexual reproduction

Answer 9

Two parents give rise to off-spring that have unique combination of gene inherited from the two parent

Question 10

Life cycle

Answer 10

A life cycle is the generation to generation sequence of stages in reproductive history of an organism, from conception to production of its own offspring

Question 11

Karyotye

Answer 11

Image of chromosomes starting with longest

Question 12

Homologous chromosomes

Answer 12

Two chromosomes of a pair have the same length , centromeres position and staining pattern.

Question 13

Female vs male chromosomes

Answer 13

Female chromosomes (XX) make chromosomes (XY)

Question 14

Sex chromosomes

Answer 14

Chromosomes that determine sex through X and Y

Question 15

Autosome

Answer 15

Another chromosomes

Question 16

Diploid cell

Answer 16

Two chromosomes set , the diploid number I. Human somatic cell is 46

Question 17

Haploid cell

Answer 17

Have single n number of chromosomes, typically 26

Question 18

Fertilisation

Answer 18

The unit of gametes, culminating in fusion of their nuclei, is called fertilisation

Question 19

Zygote

Answer 19

The resulting fertilised eggs are called zygote. This develop into multicellular organism.

Question 20

Meiosis

Answer 20

Type of division that reduces the number of set of chromosomes from two to one in gametes, counterbalancing the doubling at fertilisation

Question 21

Alternation of generation

Answer 21

Plant and some species of algae exhibit a second type life cycle called alternation of generations

Question 22

Meiosis

Answer 22

Single duplication is followed by not one but two consecutive cell division called Mei meiosis 1 and meiosis 2

Question 23

Allele

Answer 23

different version in homologous pair of gene is called alley

Question 24

Stages of Meiosis in animal cell

Answer 24

Prophase 1
Metaphase 1
Anaphase 1
telophase 1 and cytokinesis 
Prophase 2
Metaphase 2
Anaphase 2
Telophase 2 and cytokinesis

Question 25

Prophase 1

Answer 25

- centromeres movement - spindle formation - nuclear envelope - crossing over occurs at chiasm ata - microtubules attaches to kineticchores s - the homologous pair will then move toward the metaphase plate

Question 26

Metaphase 1

Answer 26

- pair of homologous chromosomes are now arranged at the metaphase plate - Both chromatids of one homologue are attached to kinetochore microtubules from one pole; those of the other homologue are attached to microtubules from the opposite pole

Question 27

Anaphase 1

Answer 27

Breakdown of protein that are responsible for sister chromatid cohesion along chromatid arm allow homologous chromosomes to seperate. - the homologous move toward opposite poles, guided by the spindle apparatus - Sister chromatid cohesion persists at the centromere causing chromatid to move as a unit towards the same pole

Question 28

Telophase 1 and cytokinesis

Answer 28

- When telophase 1 begins, each half of the cell has a complete haploid set of duplicated chromosomes. - cytokinesis and telophase 1 occur simultaneously with telophase 1 forming two haploid daughter cell - in animals cleavage furrow for - in plant cell plate is formed - in some species, chromosomes decondense and nucleus reforms - no chromosomes duplication occur between meiosis 1 and meiosis 2

Question 29

Prophase 2

Answer 29

- spindle apparatus forms. - In late prophase II, chromosomes, each still composed of two chromatids associated at the centromere, move toward the metaphase II plate.

Question 30

Metaphase 2

Answer 30

- the chromosomes are positioned at the metaphase plate as in mitosis - because of crossing over I meiosis 1, two sisters chromatids of each Chromosomes are not genetically identical. - the kineticochores of sister chromatid are attached to microtubules extending from opposite poles.

Question 31

Anaphase 2

Answer 31

Breakdown of protein holding the sister chromatid together at centromeres allow the chromatid to separate. The chromatid move toward opposite direction as individual chromosomes

Question 32

Telophase 2 and cytokinesis

Answer 32

- nuclei form - chromosomes begins to decondense - the mitotic division of one parent cell each with haploid set of (unduplicated) chromosomes - the four daughter cell are genetically distinct from one and another and for, the parent cell

Question 33

Crossing over

Answer 33

When some part of sister chromatid are exchanged

Question 34

Synapsis and crossing over

Answer 34

During prophase I, duplicated homologues pair up, and the formation of the synaptonemal complex between them holds them. Okie

Question 35

Homologous pairs at the metaphor plate

Answer 35

At metaphase I of meiosis, chromosomes are positioned at the metaphase plate as pairs of homologues rather than individual chromosomes, as in metaphase of mitosis.

Question 36

Separation of homologous

Answer 36

At anaphase I of meiosis, the duplicated chromosomes of each homologous pair move toward opposite poles, but the sister chromatids of each duplicated chromosome remain attached.

Question 37

Independent assortment

Answer 37

Each pair may orient with either its mater or parental homologous chromosomes closer to given pore . 50% chance of maternal being selected 50% chance paternal being selected

Question 38

Recombinant chromosomes

Answer 38

Individual chromosomes that carry genes derived from two different parents

Question 39

Random fertilisation

Answer 39

The fusion of a male gamete fertilisation will produce a zygote with any of about 70 trillion (2^23x2^23) diploid combination.