6.1: meiosis

Question 1

diploid number

Answer 1

two sets of chromosomes. the diploid number for humans is 46 (2x23)

Question 2

embryo

Answer 2

the stage of a multicellular organism that develops form a zygote.

Question 3

fertilization

Answer 3

the process in which an egg cell is penetrated by a sperm cell and the haploid genetic information of both make and female gametes combines.

Question 4

gametes

Answer 4

specialized cells necessary for reproduction; in animals male gametes are called sperm cells and female gametes are called egg cells

Question 5

genetic diversity

Answer 5

inherited genetic differences in a species that give many organisms a survival advantage

Question 6

haploid number

Answer 6

each set of inherited chromosomes, half the diploid number. humans inherit one set of 23 chromosomes form their female parent and the one set of 23 chromosomes form their male parent.

Question 7

homologous chromosomes

Answer 7

a pair of matching chromosomes

Question 8

sexual reproduction

Answer 8

reproduction that requires two parents and produces offspring that are genetically different from each other , from either parent and from anyone in their species

Question 9

zygote

Answer 9

the new diploid cell formed by the process of fertilization which receives half of its chromosomes from its female parent and half from its male parent.

Question 10

the role of gametes

Answer 10

haploid chromosomes are carried in gametes , which are specialized cells necessary for reproduction. when two haploid gametes join together, a diploid zygote forms. the zygote develops into an embryo and eventually into a new organism.

Question 11

meiosis I

Answer 11

in meiosis I, the cell goes through the steps of mitosis and ends up with two daughter cells

Question 12

meiosis II

Answer 12

DNA is not replicated again before meiosis II begins. the chemical messages trigger the cells to begin the cell division process. meiosis II is like mitosis because in both processes the chromatids of each chromosome are pulled to opposite poles. each daughter cell inherits one chromatid from each chromosome. the result is four haploid cells, each with half the number of chromosomes.

Question 13

crossing over

Answer 13

is an event that occurs between each chromosome pair in meiosis I. in crossing over parts of non-sister chromatids cross over each other and exchange segments of DNA.