ch 13 meiosis and sexual life cycles exam 3

Question 1

genetics

Answer 1

scientific study of heredity and variation

Question 2

heredity

Answer 2

the transmission of traits from one generation to the next

Question 3

variation

Answer 3

differences in appearance that offspring show from parents and siblings (how similar and different we look)

Question 4

genes

Answer 4

the units of heredity and are made up of segments of DNA (DNA is stretched and all our codes and traits are our genes)

Question 5

gametes

Answer 5

sperm and eggs in which genes are passed to the next generation via reproductive cells

Question 6

somatic cells

Answer 6

all cells in the body except gametes and their precursors

Question 7

locus

Answer 7

a gene’s specific position along a chromosome

Question 8

asexual reproduction

Answer 8

a single individual passes all genes to offspring without the fusion of gametes (sperm and egg)

Question 9

sexual reproduction

Answer 9

two parents giving unique combinations of genes to offspring

Question 10

life cycle

Answer 10

generation-to-generation sequence of stages in the reproductive history of an organism

Question 11

how many pairs of chromosomes do human somatic cells have

Answer 11

23 pairs (one from mom and one from dad) but 46 total chromosomes

Question 12

homologous chromosomes or homologs

Answer 12

two chromosomes in each pair are called homologous chromosomes or homologs and are the same length and shape and carry genes controlling the same inherited characters

Question 13

diploid cell

Answer 13

has two sets of chromosomes (2n=46)

Question 14

haploid cell

Answer 14

a gamete that contains a single set of chromosomes (n=23)

Question 15

GO OVER 13.3

Answer 15

GO OVER 13.3

Question 16

mutations

Answer 16

changes in an organism’s DNA and are the original sources of genetic diversity

Question 17

alleles

Answer 17

different versions of genes created by mutations. reshuffling of alleles during sexual reproduction produces genetic variation

Question 18

three mechanisms contribute to genetic variation

Answer 18

crossing over, independent assortment of chromosomes, and random fertilization

Question 19

independent assortment of chromosomes

Answer 19

homologous pair of chromosomes oriented randomly at metaphase I of meiosis

Question 20

random fertilization

Answer 20

adds to genetic variation bc any sperm can fuse with any ovum (unfertilized egg)