Lecture 18: Animal Reproduction Flashcards
Describe mitosis, what are the steps?
cell division where each cell produces two identical daughter cells and each daughter cell has the same number of chromosomes as the parent cell
- 1 copy of DNA per chromosome
- replication: 2 copies of DNA per chromosome
- cell division: chromosomes split = 1 copy of DNA per chromosome and 1 chromosome per daughter cell
- product: 2 identical daughter cells
Describe meiosis - include steps
cell division where each cell produces FOUR unique daughter cells that each have HALF the number of chromosomes as the parent cell
- 1 copy of DNA per chromosomes
- Replication: 2 copies DNA per chromosomes
- cell division 1: homologous pairs split
- cell division 2: replicated chromosomes split
- products: 4 genetically unique daughter cells with half the chromosomes of parent cell
Describe haploid cells. Which cells are these?
1 copy of each chromosome per cell (n)
reproductive cells aka GAMETES (egg and sperm)
Describe diploid cells, which cells are these?
2 copies of each chromosome per cell (2n)
somatic cells aka body cells that aren’t reproductive cells
Describe a typical sexual life cycle in animals - identify the main stages and processes
Diploid stage –> meiosis –> haploid stage –> fertilization –> diploid stage
- females produce non-motile haploid (gametes) eggs by the process of MEIOSIS
- Males produce swimming haploid (gametes) sperm by the process of MEIOSIS
- Haploid gametes fuse by FERTILIZATION to form a diploid zygote
- diploid zygote divides by MITOSIS to produce a new multicellular individual
T or F: mitosis produces two identical daughter cells with the same number of chromosomes as the parent cell therefore, the daughter cells are genetic clones
true
Describe and give examples of budding. State which kind of reproduction this is & give an example of animals
a form of asexual reproduction that occurs when new individuals grow as offshoots (buds) from the parent’s body and detach when they are self-sufficient
ex. cnidaria, porifera, and platyhelminthes
- hydra
Describe and give examples of fragmentation. State which kind of reproduction this is & give an example of animals
a form of asexual reproduction where one individual breaks into two or more parts and each part grows into a new individual
ex. some echinodermata, porifera, cnidaria, and annelida
- specific: coral
Describe and give examples of parthenogenesis. State which kind of reproduction this is & give an example of animals
a form of asexual reproduction that produces a diploid offspring from eggs that are not fertilized by sperm
ex. insects like aphids
some reptiles like anaconda
fish - sharks
Advantages and disadvantages of sexual reproduction
Advantages:
disadvantages:
- complications finding a mate (time, energy)
- energetically costly - courtship and competition
- dangerous - risk of disease, predation, and injury
Advantages and disadvantages of asexual reproduction
advantages:
- the parent passes on 100% of its genetic material (offspring = genetically identical clones)
- reproduction can occur sooner, more frequently, and with lower costs & complications
disadvantages:
- diversity is limited –> makes populations vulnerable to disease
- inability to adapt
define gonochoristic animals and give examples
sexual organisms that have one sexual organ on one individual
ex. humans
define hermaphroditic animals and give examples
both sexual organs on a single individual - can be simultaneous or sequential
describe the two kinds of hermaphroditic animals and provide examples
- simultaneous hermaphrodites: have both female and male reproductive structures (ex. earthworms)
- sequential hermaphrodites change sex during their lifetime (ex. parrot fish)
describe external fertilization
female releases eggs into the aquatic or moist terrestrial habitat and males release sperm onto them
describe internal fertilization
sperm deposited inside female reproductive tract and egg is fertilized inside female’s body
describe and give examples of oviparous
species in which offspring develop in eggs (outside of their mother)
- nourished by egg yolk and hatch externally
describe and give examples of viviparous
species in which offspring develop inside of their mother, not within an egg
- nourished by placenta and live birth
describe and give examples of ovoviviparous
species in which offspring develop inside of an egg inside of their mother until they are ready to hatch
- nourished by yolk and live birth
T or F: meiosis only occurs in the reproductive organs of sexually reproducing animals? why/why not?
TRUE because meiosis produces haploid cells/gametes which are the reproductive cells in animals
Which cell division process would a diploid cell use to produce haploid cells?
MEIOSIS
Which cell division process would a diploid cell use to produce haploid cells?
MEIOSIS
Haploid cells undergo which process to produce new diploid cells?
FERTILIZATION
Define fertilization
the process in a sexual lifecycle that occurs when the male gamete (sperm) fuses with the female gamete (egg) to produce a diploid zygote
Are zygotes diploid or haploid? why?
Diploid because they are the product of two haploid cells fusing and the product of the process fertilization
Are zygotes diploid or haploid? why?
Diploid because they are the product of two haploid cells fusing and the product of the process fertilization
Describe sexual reproduction
occurs through internal fertilization to produce a genetically unique individual
the individual is genetically unique because half the chromosomes come from the mom and half from the dad
What cell division process is involved in budding and fragmentation?
MITOSIS because it produces genetically identical clones
T or F: many species that mostly use asexual reproduction will have sex and produce genetically unique offspring at some stage in their life cycle
True. example aphids reproduce by parthenogenesis all summer, but reproduce sexually in the fall when environmental conditions start changing
Define broadcast fertilization and provide an example
release masses of eggs and sperm into the water sos the sperm swim to eggs
ex. sea urchins
what is a major advantage of internal fertilization over external fertilization?
There is a higher chance of successful reproduction when its directly inside the female
T or F: all three types of offspring development are represented by species of fish in the group referred to as sharks
True
T or F: all three types of offspring development are represented by species of fish in the group referred to as sharks
True
Which of the offspring development types can be associated with external fertilization?
oviparity
if embryos develop inside mothers body, then fertilization must be internal
