chapter 10 biology asexual and sexual reproduction

in asexual production how many parents does an offspring have

1

what are the advantages of asexual production

it is faster, large numbers of offspring are produced, the parent does not have to find a mate

what are the disadvantages of asexual production

all of the offspring are exactly alike, the ability to adpat to a changing environment is greatly reduced

sexual reproduction requires how many parents

2

in sexual production there must be a

male and female

in sexual production each parent passes off what to its offspring

half of its genes

what are the disadvantages of sexual production

the parent must find a mate, very few offspring are produced, it takes longer

what are the advantages of sexual reproduction

all of the offspring are different

sexual production always involves

gametes, fertilization, and zygote

gametes are

sex cells

fertilization is

the union of sperm and egg

zygotes are

fertilized eggs

if an organism is a result of sexual reproduction it will have

two sets of chromosomes

where do the two sets of chromosomes come from in sexual reproduction

one set from the mother, one set from the father

what are the who sets of chromosomes called in sexual production

homologous chromosomes

homologous chromosomes carry the same genes but

they may have different expressions of that gene

what does diploid mean

that there are two kind of each chromosome in each cell

what is the symbol for diploid

2N

diploid cells contain

two complete sets of chromosomes

egg and sperm must have _____ the number of _______ so that when added together the zygote will have the_______

half, chromosomes, proper number

gametes are said to be____ or_____- because they only contain only one kind of each chromosome

haploid, 1N

meiosis is

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

meiosis occurs in

sex cells only- egg and sperm

what is the purpose of meiosis

reduce the chromosomes number od the egg and sperm in half

what is the difference between meiosis and mitosis

in meiosis the replication is then followed by two divisions, meiosis I and meiosis II

what happens in interphase

the chromosomes replicate

what are the two identical sisters called in interpahse

chromatids

what are chromatids held together by interphase

centrome

what happens to the chromosomes in Prophase I

they shorten and thicken

what does each chromosome do in prophase I

pair wuth its corresponding homologous chromosome to form a tertad

how many chromatids are in a tetrad

4

what happens in metaphase 1

tetrads line up at the center of the cell

what happens to the tetrads in anaphase 1

they break apart and the pair move to the opposite sides of the cell

what do the sister chromatids do in anaphase (attachment) 1

the remain attached at their chromosomes

what happens to the cell in telophase and cytokinesis

it separates into two

what does meiosis result in

2 haploid daughter cells

what happens during prophase 2

pairs of sister chromatids start towards the center

what happens during anaphase

the sister chromatids move to opposite sids of the cell

what does telophase 2 and cytokinesis result in

4 new cells that are 1N