Reproduction Flashcards
What is Asexual Reproduction
genetically identical cells are produced from a single parent cell through mitosis
What are the Pros and Cons of Asexual Reproduction?
Pros: No mate necessary; genetically identical
Cons: Genetically identical
Binary Fission
division of one cell into two equal or nearly equal parts or daughter cells
-happens in most single celled organisms
Budding
adult cell or organism grows smaller daughter cells or organism
-single and multicellular organisms-all non-bilaterian taxa
Vegetative Reproduction
new individuals are created from parts of adults
ie: shoots, cutting
Fragmentation
occurs in simple animals (echinoderms, porifera, etc)
Parthenogenesis/Apomixis
Parthenogenesis: development in animals without fermentation
ie: sharks, reptiles
Apomixis: same definition but in plants
egg can develop without being fertilized by sperm
What is Sexual Reproduction?
reproduction that involves the combination of genetic information from 2 parent individuals
Does Sexual Reproduction occur in prokaryotes, eukaryotes, or both?
Eukaryotes
What are the Pros and Cons of sexual reproduction?
Pros: genes are recombined to form an entirely new genome
Cons: must find a mate; must undergo mating
Conjugation
- ciliates
- genes are tranferred through a micronucleus
- micronuclei fuse together to form a new genome
What is fertilization?
When 2 cells fuse together
most multicellular organisms produce________
haploid games
ie: sperm or egg
Fertilization results in what?
a diploid zygote
Dioecious
organism that produce only one type of gamete
-male/female
Monoecious
organism that produces both types of gametes
-hermaphroditic
What are spores?
cells dispersed for breeding purposes
-Always haploid
Diplontic life cycle
only the diploid stage is multicellular
-haploid stage is one gamete cell
Haplodiplontic life cycle
- multicellular diploid stage=Sporophyte
- multicellular haploid stage=Gametophyte
Chlorophytes and Charophytes
- Haplodiplontic life cycle
- gametophyte and sporophyte appear identical
- +/- gametes
Bryophytes
-Haplodiplontic life cycle
-gametophyte is dominant
Archegonia=female
Antheridia=male
After fertilization…..
-archegonia grows a sporophyte stalk
-sporophyte is nonphotosynthetic
-sporophyte produces spores
Brown Algae
- haplodiplontic life cycle
- sporophyte dominant
- egg and sperm
Pteridophytes
- haplodiplontic
- sporophyte dominant
- produce sori on the back of fronds
- small gametophyte with anthredia and archegonia
- the gametophyte is free-living and photosynthetic
- sperm fertilizes egg
Seed Plants
- Haplodiplontic
- microgametophyte and megagametophyte
Gymnosperms
-sporophyte produces male and female cones
-pollen grains develop in male and cones by meiosis
-female cones are larger and have woody scales
-pollen grains drift down female cones
-pollen tube emerges from the pollen grain
(look up what it does in notes)
Angiosperms
-posses flowers and fruits
-floral organs are thought to have evolved from leaves
-
Complete Flower
has four whorls
Incomplete flower
lacks 1 or more of these whorls
Calyx
consists of sepals
Corolla
consists of petals
Androecium
collective term for stamens
What do stamens consist of?
a filament and an anther
Gynoecium
collective term for carpels
What do carpels consist of?
an ovule, ovary, style and stigma
Microgametophyte
Four microscopes form through meiosis and become pollen grains. Each consists of:
- tube cell
- generative cell that will later divide to 2 sperm cells
Megagametophyte
- female gametophyte
- 2 become polar nuclei
- at the micropyle end, one cell functions as the egg, and the other two are synergids
- at the other end, three cells are antipodals
pollination
the process by which pollen is placed on the stigma
self-pollination
pollen from flower anther pollinates stigma of same flower
cross-pollination
pollen from anther of one flower pollinates the anther of another flowers stigma
bees
most common insect pollinators
nectar guides
Butterflies
prefer flowers that have flat “landing platforms”
Birds
like red flowers
usually inconspicuous to insects
plants that get wind pollinated
small green and odorless
often grouped and hanging down in tassels
Angiosperms undergo a unique process called _________
Describe this
Double Fertilization
-tube cells form a pollen tube
-generative cell divides to form 2 sperm cells
One sperm cell fuses with the egg cell to form the diploid zygote
-other sperm cell nucleus fuses with the two polar nuclei to form the triploid endosperm
-nourishes embryo
Fungi Fertilization
fertilization by merging hyphae cells from 2 individuals
- Karyogamy
- sometimes forms a dikaryotic cell before karyogamy
Basidomycota
see notes
True or False
Most animals reproduce asexually
false
True or False
fertilization evolved on land first
false
fertilization evolved in the ocean before animals colonized land
External fertilization
eggs and sperm are released into the water where union of the free gametes occurs
Internal fertilization
sperm are introduced into the female reproductive track
What are the three strategies of developement of internal fertilization?
Oviparity: fertilized eggs are deposited outside mothers’ body to complete their development
Ovoviviparity: fertilized eggs are kept within mother to complete development, and young obtain food from egg yolk
Viviparity: young develop within mother and obtain nourishment from her blood
What animal type is viviparous, ovoviviparous, and oviparous?
cartilaginous fish
Give three details about amniotes
- the amntiotic egg has four membranes
- water tight
- results from internal fertilization
Most reptiles and birds are viviparous, ovoviviparous, or oviparous?
oviparous
what is copulation?
males uses a penis to inject sperm into the female
what is ovulation?
the period release of a mature egg
what is the estrous cycle?
- occurs in most female mammals
- females are only receptive to males around ovulation (estrous)
what is the menstrual cycle?
shedding of the inner lining of the uterus
What the difference between the estrous cycle and the menstrual cycle?
Menstrual cycle= female can copulate at any time in their cycle; in the Estrous cycle females copulate when they are ovulating
are monotremes viviparous, ovoviviparous, or oviparous?
oviparous
are marsupials viviparous, ovoviviparous, or oviparous?
viviparous
are placentalsviviparous, ovoviviparous, or oviparous?
viviparous
