W10 Flashcards
What are the two main ways of reproduction?
Sexual and Asexual
Define Asexual reproduction
The production of cells that are identical to parent cells. Also known as clones
What are the main types of Asexual reproduction?
- Budding
- Fragmentation
- Parthenogenesis
Although Prokaryotic divide Asexual to create clones, what are some ways genetic variation can be gained?
- Horizontal gene transfer
- Obtain DNA directly from the environment and viral infection
How does the process of horizontal gene transfer work?
Transfer DNA from one individual to another, usually of the same species, and much more rarely to an individual of another species, during conjugation.
What is budding?
In which a bud or small protrusion forms on an organism and eventually breaks off to form a new organism that is smaller than the parent. Fungi, Plants and some animals
What is Fragmentation?
In which new individuals arise asexually by the splitting of one organism into pieces, each of which develop into a new individual.Some mold, starfish and corals
What is Parthenogenesis?
Females produce eggs that are not fertilized by males, but divide by mitosis into new individuals
Define sexual reproduction
The process of producing offspring that receive genetic material from two parents; In Eukaryotes this process occurs through meiosis and fertilization
What are n cells also known as
Gametes or spores
What is the result of fertilization or fusion of two gametes?
A Zygote
Define embryo
An early stage of multi-cellular development that results from the successive mitotic division of the zygote
True or false, organisms that reproduce asexually are also capable of producing sexually?
True
What determines whether an organism reproduces sexually or Asexually if it can do both?
As demonstrated by the Daphnia, the determining factor seems to be whether the environmental conditions create favorable conditions or Less favorable conditions
What consists favorable Conditions?
- Abundant food supply
- Warm temperatures
What consists less favorable Conditions?
- Decreased food supply
- Cool temperatures
- Overcrowding
- Accumulation of wastes
What are the advantages of Asexual reproduction?
- It does not involve finding a mate, which takes time and energy
- Less genetic variation
What is the main benefit of Asexual reproduction?
It is rapid and allowing organisms to increase their population quickly. Even growth exponentially if conditions are favorable
What is the twofold cost of sex?
Is one of the key disadvantages of sexual reprodcution.Population size can increase more rapidly in asexually reproducing organisms than in sexually reproducing organisms because only female produce offspring, and sexual females have only half the fitness of asexual parents.
What is 1/3 of the explain the advantages of producing genetically distinct offspring in spite of the costs of sexual reproduction.
sexual reproduction allows species to adapt faster than Asexually reproducing ones because rare beneficial mutations that arise in different organisms can be brought together, increasing the overall fitness of the population
What is 2/3 of the explain the advantages of producing genetically distinct offspring in spite of the costs of sexual reproduction.
Sexual reproduction allows a population to purge itself of harmful mutations more quickly than could a population of asexual individuals.
What is 3/3 of the explain the advantages of producing genetically distinct offspring in spite of the costs of sexual reproduction.
Sexual reproduction is a mechanism of parasite defense. In host–parasite interactions, the host evolves defenses against the parasite, and the parasite evolves new ways to infect the host, so each evolves rapidly simply to maintain its ecological position.
What is a hypothesis that explains why mammals have lost the ability to produce asexually?
We can hypothesize that early mammals gained fitness advantages in the evolution of imprinted genes, but lost the ability to reproduce parthenogenetically
What are imprinted genes?
Genes that are expressed differently depending on their parent of origin. Imprinting ensures that mammals develop from embryos with one maternal and one paternal genome
