animals lecture 12 & 13 Flashcards
formation of new individuals whose genes come from one parent and never uses males gametes.
asexual reproduction
formation of new individuals by the fusion of haploid gametes
sexual reproduction
types of asexual reproduction
Fission, Fragmentation, Budding, Parthenogenesis
separation of parent into two or more individuals of approximately equal size.
fission
breaking of the body into pieces and regeneration of lost body parts to create new individuals.
fragmentation
examples of animals that do fragmentation
Turbellaria, Annelids, Echinoderms
: new individuals arise from outgrowths of existing ones
budding
examples of animals that do budding
sponges, hydrozoans, tunicates
: development of embryos without fertilization
parthenogenesis
examples of parthenogenesis
A few crustaceans, sharks, fish, salamanders, and few lizards and snakes
types of sexual reproduction
gonochoristic and hermaphroditic
males and females are
Different individuals
gonochoristic (diecious)
): an individual can produce both male and female gametes
hermaphrodistic (monoecious)
tradeoff of asexual reproduction and selfing
Potential for rapid population growth, Don’t need to find mate, Low Genetic variation.
tradoffs of sexual reproduction
Increases genetic variability, Lower population growth, Need to find a mate.
sex determined genetically at the time of fertilization.
Eg. birds, mammals, snakes and some lizards
genotypic sex determination
sex is determined by egg incubation temperature
Eg. turtles, many lizards, and crocodilians
temperature dependent sex determination
a creeping horizontal plant stem or runner that takes root at points along its length to form new plants.
stolon
involves the formation of haploid cells from an original diploid cell, called a primary oocyte, through meiosis. The female ovaries contain the primary oocytes. leads to the production of one final ovum, or egg cell, from each primary oocyte (in contrast to the four sperm that are generated from every spermatogonium). Of the four daughter cells that are produced when the primary oocyte divides meiotically, three come out much smaller than the fourth. These smaller cells, called polar bodies, eventually disintegrate, leaving only the larger ovum as the final product
oogenesis
male testes have tiny tubules containing diploid cells called spermatogonium that mature to become sperm. The basic function is to turn each one of the diploid spermatogonium into four haploid sperm cells. millions produced every day for each individual
spermatogenesis
breed (an animal or plant) with one not closely related.
outcrossing
in the male, it develops into parts of the male reproductive system, such as the epididymis and the vas deferens; in the female, it becomes vestigial.
wolffian duct
persist, in females, to develop into the fallopian tubes, the uterus, and part of the vagina; in males they are largely suppressed
mullerian duct
the tube through which an ovum or egg passes from an ovary.
oviduct
is part of the male reproductive system of many vertebrates; these vasa transport sperm from the epididymis to the ejaculatory ducts in anticipation of ejaculation.
vas deferns
takes place when animals release their eggs and sperm into the water, where fertilization occurs externally. one of the most common methods of reproduction in the sea
broadcast spawning
the mating position of frogs and toads, in which the male clasps the female about the back.
amplexus
individuals reverses its
sex during its lifetime
sequential hermaphroditism
distinct difference in size or appearance between the sexes of an animal in addition to difference between the sexual organs themselves.
sexual dimorphism
methods of attracting mates
visual displays, calls, tactile, phermones
reproduces many offspring, but provides little parental care
r strategist
reproduces few offspring, but typically provides a lot of parental care
k strategist
costs of parental care
decrease parental survival, increase time until next breeding, reduce future fecundity
believed until the 1800s; sperm or egg contain a miniture infant called a homunculus that only increases in size during development
preformation
a supposed microscopic but fully formed human being from which a fetus was formerly believed to develop
homunculus
the unfolding of an organism across its ontogeny
development
early cell divisions after fertilization
cleavage
schizocoelous
protosomes
enterocoelous
deuterosomes
epidermis of skin and derivitaves; epithelial lining of mouth and rectum; sensory receptors in epidermis; cornea and lens of eye; nervous system; adrenal medulla; tooth enamel
ectoderm
notochord; skeletal system; muscular layer of stomach, intestine; excretory system; circulatory and lymphatic systems; reproductive system; dermis of skin; lining of body cavity
mesoderm
epithelial lining of digestive tract; epithelial lining of respiratory system; lining of urethra, urinary bladder, and reproductive system; liver; pancreas; thymus; thyroid and parathyroid glands
endoderm
germ layers form rudiments of organs
organogenesis
what determines developmental patterns
genetics and environment
phenotype depends on environment
plasticity
development is consistent across environments
canilization
a phase early in the embryonic development of most animals, during which the single-layered blastula is reorganized into a trilaminar (“three-layered”) structure known as the gastrula. These three germ layers are known as the ectoderm, mesoderm, and endoderm.
gastrulation
the opening of the central cavity of an embryo in the early stage of development.
blastopore
transplant experiments told us that
species specific info is present in the transplanted tissues and that tissue is played out a predetermined developmental pathway
the pathway taken by a cell and its progeny
cell fate
process by which a cell develops into a more specialized type of cell
cellular differentiation
potential medical applications of stem cells
regeneration, replacement, drug discovery, developmental/molecular biology
potential issues with stem cells
social/legal issues, allogenics
(in genetics) denoting an individual or cell type that is from the same species but genetically distinct.
2 (in transplantation biology) denoting tissues, particularly stem cells from either bone marrow or peripheral blood, that are from the same species but antigenically distinct; homologous
allogenic
abnormal and uncontrolled growth and proliferation of cells in the body
cancer
what can cause cancer
inherited genetic mutations, non-inherited genetic mutations during replicaiton, toxins, UV, radation, carcinogens, viruses
an undifferentiated cell of a multicellular organism that is capable of giving rise to indefinitely more cells of the same type, and from which certain other kinds of cell arise by differentiation.
stem cell
