Unit 10

Question 1

Define Fertilization

Answer 1

the process in sexual reproduction where the male and female reproductive cells join

Question 2

Define True-breeding

Answer 2

organisms that, if allowed to self-pollinate, would produce offspring identical to themselves

Question 3

Define Trait

Answer 3

specific characteristic that varies among individuals

Question 4

Define Hybrid

Answer 4

Offspring crosses between parents with different traits

Question 5

define Allele

Answer 5

Different forms of a gene

Question 6

Define Segregation

Answer 6

separation of alleles pairs during gamete formation

Question 7

Define homozygous

Answer 7

organisms that have two identical alleles for a particular trait

Question 8

define heterozygous

Answer 8

organisms that have two different alleles for a particular trait.

Question 9

define phenotype

Answer 9

physical characteristics

Question 10

define genotype

Answer 10

genetic makeup

Question 11

Define independent assortment

Answer 11

alleles for a trait segregate independently

Question 12

define incomplete dominance

Answer 12

cases in which one allele is not completely dominant over another

Question 13

define multiple alleles

Answer 13

genes with more than two alleles

Question 14

define polygenic traits

Answer 14

traits that are controlled by two or more genes

Question 15

define homologous

Answer 15

chromosomes that have the same structure, function, and relative location

Question 16

define diploid

Answer 16

cell that contain both sets of homologous chromosomes

Question 17

define haploid

Answer 17

cell with only one set of chromosomes

Question 18

define tetrad

Answer 18

the structure formed when chromosomes pair up with corresponding homologous chromosomes in prophase of meiosis I

Question 19

define crossing over

Answer 19

exchange in portions of a chromatid

Question 20

Define Nondisjunction

Answer 20

common error in meiosis where sister chromatids fail to separate

Question 21

what Mendel’s law hereditary?

Answer 21

The principle of dominance states that some alleles are dominant and others are recessive.
The principle of probability can be used to predict the outcomes of genetic crosses.
The principle of independent assortment states that genes for different traits can segregate independently during the formation of gametes.

Question 22

what are characteristics also influenced by?

Answer 22

environmental and nutritional factors

Question 23

What is meiosis

Answer 23

a process of reduction division in which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell.

Question 24

explain interphase I

Answer 24

cells undergo a round of DNA replication, forming duplicate chromosomes.

Question 25

explain prophase I

Answer 25

each chromosome pairs with its corresponding homologous chromosome to form a tetrad.

Question 26

explain Metaphase I

Answer 26

Spindle fibers attach to the chromosome.

Question 27

explain Anaphase I

Answer 27

The fibers pull the homologous chromosomes towards opposite ends of the cell.

Question 28

Explain telophase I and cytokinesis

Answer 28

Nuclear membranes form. The cell separates into two cells.

Question 29

explain Prophase II

Answer 29

Meiosis I results in two haploid (N) daughter cells, each with half the number of chromosomes as the original cell.

Question 30

explain metaphase II

Answer 30

chromosomes line up like the similar way in metaphase I

Question 31

Explain Anaphase II , Telophase II and cytokinesis

Answer 31

The sister chromatids separate and move toward opposite ends of the cell. Meiosis II results in four haploid daughter cells

Question 32

what is gene linkage?

Answer 32

the tendency of DNA sequences that are close together on a chromosome to be inherited together

Question 33

why are all x-linked alleles expressed in males?

Answer 33

because they only have one X-chromosome

Question 34

what are 3 ways sexual reproduction is increases variation?

Answer 34

Independent assortment, random fertilization, and crossing over