lab 4 Flashcards
what is a diploid organism
have two sets of chromosomes in their cells 2n
what is an allele
an alternative version of a gene (dominant or recessive)
what is a gene
unit of hereditary info that contributes to inheritable traits of organism
what are homologous chromosomes
chromosomes that have the same shape, size, centromere position, and sequence of genes
when do homologous chromosomes pair up
in prophase 1
what do homologous chromosomes form in pair up
tetrad
meiosis 1 (diploid to haploid)
first division when homologous chromosomes separate into two different cells
what happens to chromosome number at the end of meiosis 1
chromosomes are halved
what is meiosis 2
second division when replicated chromosomes are separated into single chromosomes
what is ploidy
number of sets of chromosomes in a cell
n= number of chromosomes
haploid
2n= number of chromosomes
diploid
what is a eukaryote considered in only one of each type of chromosome in nucleus? haploid or diploid
haploid
when is replicated chromosome formed
when single chromosome undergoes DNA synthesis
are replicated chromosomes identical or not
identical and carry same alleles
where are genes found
loci or location
what are dominant alleles
capital letters
what are recessive alleles
lower case letters
what is the genotype
ordered list of alleles it carries for any gene
what happens during prophase 1
crossing over, chromosome condense, spindle microtubules form, tetrad form
what happens during prometaphase 1
nuclear envelope breaks down, spindle microtubules attach to centromere
what happens during metaphase 1
tetrad line up in midregion
what happens during anaphase 1
homologous chromosomes separate and move to opposite sides
what happens during telophase 1
nuclear envelope re-forms, replicated chromosomes arrive at pole and uncoil, spindle disappear, cytokinesis
what happens during interkinesis
DNA doesnt replicate and very short stage
what happens during prophase 2
chromosomes replicate, and spindle apparatus form
what happens during prometaphase 2
nuclear envelope break down. spindle microtubules attach to centromere
what happens during metaphase 2
replicated chromosomes line up on midline
what happens during anaphase 2
centromeres separate and single chromosomes move to opposite sides
what happens during anaphase 2
centromeres separate and single chromosomes move to opposite sides
what happens during telophase 2
chromosomes uncoil, spindles disappear, nuclear envelope re-forms, nucleoli visible, cytokinesis, and 4 daughter cells
what are diploid cells called during meiosis of plant cells
sporocytes
what are reproductive organs called within sporocytes
sporangia
what do sporangia form
haploid spores
what is plant cells life cycle called
alternation of generation
what is diploid generation called in plants
sporophyte
where are haploid spores produces by meiosis within?
sporangia
what does alternating of generations mean
distinct multicellular haploid and diploid stages
what do spores produce as they undergo meiosis
multicellular haploid gametophyte
what are within gametophyte
reproductive organs that produce gametes by mitosis
what is more dominant in plants sporophyte or gametophyte
sporophyte; diploid most obvious stage
what is the male gametophyte in flowering plants
pollen grains
what are rhizome
underground stem that large leaves grow from
what are brown sports called on ferns
sori
where do sori develope
underside of mature leaves
what is each sorus reproductive structure called
sporangia
what are diploid cells called inside of sporangium
sporocytes
do sporocytes undergo meiosis or mitosis
meiosis
what are sporocyte haploid cells called
spores
what happens when spores mature
discharge from sporangia
what shape are fern gametophyte
tiny heart shapes called prothallus
what are the fine root like structures of gametophyte called
rhizoids
what are the reproductive organs called of gametophytes
male= antheridia
female= archegonia
gametophyte go through mitosis and produces what?
antheridia= sperm
archegonium= egg
what happens after fertilization between antheridium and archegonium
diploid zygote develops by repeated mitotic division
what are the reproductive organs in animals
ovaries and testes
what are the reproductive organs in animals
ovaries and testes
in animals life cycle what does nuclear division result in
haploid gametes
what is chiasma
the region where crossing over happens in prophase 1
where does meiosis only occur in animals
in ovaries and testes
in animal life cycle does it go under mitosis or meiosis
mitosis
