Meiosis and Sexual Life Cycles

AP Biology Unit 5 Quiz

How do offspring acquire genes from parents?

By inheriting chromosomes

what is the transmission of traits frm one generation to the next called?

inheritance or HEREDITY

Offsprings are ___________________ copies of either parent or pf their siblings

not identical

Along with inherited similarity, there is ___________

variation

what are genes

units of heredity

What are genes made of?

made up of segments of DNA

how are genes passed to the next generation

via reproductive cells called gametes (sperm and eggs)

how is most DNA packaged

into chromosomes

how many chromosomes do humans have (not the # of pairs)

46

what are somatic cells

all cells of the body except gametes and their precursors

where are the 46 chromosomes in humans

in the nuclei of their somatic cells

what is a locus

a gene’s specific position along a chromosome

how does asexual reproduction work

a single individual passes all of its genes to its offspring w/o the fusion of gametes

what is a clone

a clone is an individual or group of genetically identical individuals from the same parent

how does sexual reproduction work?

two parents give rise to offspringf that have unique combinations of genes inherited from the two parents

what is a (sexual) life cycle?… (chromosomes?)

a life cycle is the generation to generation sequence of stages in the reproductive history of an organism

the behavior of chromosomes are related to the human lifecycle and other types of sexual life cycles

how many pairs of chromosomes do human somatic cells have?

23 pairs

what is a karyotype

an ordered display of the pairs of chromosomes from a cell

what are the two chromosomes in each pair called?

homologous chromosomes or homologs

how are chromosomes in a homologous pair?

they have the same length, centromere position, and staining pattern
They also carry genes controlling the same inherited ccharacters

what are the sex chromosomes, which determine the sex of the individual, called

X and Y

female sex chromosomes:

XX

Male sex chromosomes:

XY

what are the remaining (non sex chromosomes) called?

autosomes

what does each pair of homologous chromosomes include?

one chromosome from each parent; the 46 chromosomes in a human somatic cell are two sets of 23: one from the mother and one from the father

what is a diploid cell?

(2n) has two sets of chromosomes

for humans what is the diploid number?

46 or 2n = 46

in a dcell in which DNA synthesis has occurred, each chromosome is ______________

replicated

what does each replicated chromosome consist of ?

sister chromatids

what is a gamete

a sperm or egg

is a gamete a diploid or a haploid cell?

haploid (n) → contains a single set of chromosomes

what is the haploid number for humans

n = 23

in an unfertilized egg (ovum), what is the sex chromosome

X

in a sperm cell, the sex crhomosomes may be …

X or Y

what is fertilization

the union of gametes (the sperm and the egg)

what is a fertilized eggs called?

called a zygote and has one set of chromosomes from each parent

how does a zygote produce somatic cells

produces somatic cells by mitosis and develops into an adult

which organs produce gametes

the ovaries and testes produce haploid gametes

gametes are the only type of human cells produced by ___.

meiosis

what does meiosis result in (pertaining to chromosomes and sets)

meiosis results in one set of chromosomes in each gamete

______________ and __________ alternate in sexual life cycles to maintain chromosome number

1. fertilization

2. meiosis

teh alternation of meiosis and fertilization is _____________________ to ____ organisms that reproduce sexually

1. common

2. all

the three main types of sexual life cycles differ ijn the timing of _______________ and ___________

1. meiosis

2. fertilization

what is the life cycle of an animal

what is the life cycle of plants and some algae

what is the life cycle of most fungii and some protists

_________________ are the only haploid cells in most animals

gametes

how are gametes produced

by meiosis and undergo no further cell division before fertilization

how do gametes debvelop into a multicellular organism

gametes fuse to form a diploid zygote that divides by mitosis to develop into a multicellular organism

what life forms exhibit an alternation of generations?

plants and some algae

do the life cycles of plants and some algae exhibit a diploid &/or a haploid multicellular stage

both diploid ajd haploid stages are present