Chapter 47 Reproduction Flashcards
(37 cards)
what are some advantages of asexual reproduction?
- no mate necessary
-many offspring in little time
-perpetuation of successful genotypes
-reduction of heterozygosity in population
-natural selection happens faster
-works great if sessile
what are the main types of asexual reproduction?
budding- new individual grows off on an individual. common in hydra and yeast
gemmules- bundle of archeocytes with spicules, left with internal buds, give rise to new bud
Fragmentation- happens from injury, organism will break into several fragments, each can develop into new organism (starfish and flatworms)
Fission- organism splits into two equal parts, each part develops into new organism. Common in bacteria
Parthenogenesis- process where unfertilized egg develops into a new organisms. common in fish, reptiles, insects.
what is TSD?
temperature sex determination. Temperature of incubation determines the sex of the organism.
what is GSD?
Genetic sex determination. genetic determine the sex. In birds have W-Z for female and ZZ for males. There is X-Y for mammals, where it is determined by the presence of the Y chromosome, if Y is there then it is male (XY) and (XX) is female. In some insects it is X-O which by the number of sex chromosomes determines sex of the offspring.
what is haplodiploidy?
In these species (ants, insects and bees), the offspring will be female if developed from a fertilized egg and have two sets of chromosomes where as males develop from unfertilized eggs and have one set of chromosomes.
what is Parthenogenesis?
Using tools of sexual reproduction for asexual reproduction. Genetic material comes solely from the mother, as the egg develops into an embryo without having to be fertilized by a sperm cell.
What is myxis ? How does it work?
When a species alternates from male to female. Females produce diploid eggs (females) stress comes along females produce haploid eggs (Males), males fertilize eggs- stay dominant until conditions improve return to female dominant.
What is myxis ? How does it work?
When a species alternates from male to female. Females produce diploid eggs (females) stress comes along females produce haploid eggs (Males), males fertilize eggs- stay dominant until conditions improve return to female dominant.
What is the relative reproductive investment for males and females in terms of gametes?
females have high reproductive investment while males have low reproductive investment
what advantages are there in sexual reproduction?
-increases in genetic variation
-good for changing environments
-good for motile organisms
-larger offspring
What does monoecious and dioecious mean?
Monoecious: everybody is the same, one sex
Dioecious: two sexes, male or female
What is gonochorism? What is sexual dimorphism?
Gonochorism: individuals can be male or female at any given time, switch sexes
Sexual Dimorphism: male and female look different
What is hermaphroditism?
Sequential Hermaphroditism: dioecious, has both male and female parts but at different points in life (e.g. clownfish)
Synchronous Hermaphroditism: monoecious, both male and female gonads at the same time
how does sexual dimorphism relate to the idea that “sperm are cheap”?
sperm is easy to make.
what are some of the problems with sexual reproduction?
-Cost: it is energetically costly, have to find mate and produce gametes
-Competition: competition between individual mates
-Risks of Diseases
-Limited genetic diversity
-Inefficiency: variably in offsprings traits
what are some of the differences in internal and external fertilization?
Internal Fertilization: cooperative behaviour among individuals, cupulation is involved. Occurs inside the female body
External Fertilization: mostly aquatics, synchronous reproduction, male and female must do it at the same time for success, occurs outside the female body
Describe spider sex
Dioecious. Males contain pedipalps which they use to deliver sperm on to the female spider. They can break of pedipalps in the female or just on their own. Females have an epigynum which is the external genital structure. The female contains a spermatheca which is where she can hold sperm from a male for up to a year before she decides she wants to use it. Females will do sexual cannibalism which is when she kills male spider after mating.
What is the arrangement for openings for digestive, urinary and reproductive systems in mammals?
In mammals the opening for the digestive, urinary and reproductive systems are separate and distinct. The digestive system has two openings: the mouth which leads to the digestive tract and the anus, which is the exit point for undigested food and waste. The urinary has one opening, the urethra, which carries urine from the bladder out of the body. The reproductive system has separate openings for male and females. In males the reproductive opening is the penis, which is used for both urination and ejaculation. In females, the reproductive opening is the vagina which leads to the cervix and then the uterus. The urethra is also present in females, but is separate from the reproductive system and is only used for urination.
what are the modes of reproduction in vertebrates?
ovipary- nutritionally independent egg, this is many fish, many reptiles, birds, monotremes (platypus)
ovovivpary- nutritional investment egg, hatches inside the body, this is some reptiles, some fish, some amphibians
vivipary- embryo produced, not nutritionally independent, mother feeds in stomach, this is some fish, some amphibians, most mammals, and some reptiles. live births
describe the human anatomy of a male reproductive system.
testes, epididymis, seminal vesicles, prostate glands, bulbourethral glands, penis. meant to deliver sperm to egg.
what is lagomorphs?
penis is behind scrotum instead of front. In rabbits, hares, pikas
what are seminiferous tubules?
narrow, coiled tubules that produce sperm in the testes.
what are leydig cells?
produce testosterone
what is the epididymis?
a long, coiled duct on the outside of the testis in which sperm mature.
