Exam-style Questions Flashcards
(21 cards)
Explain how seeds are selected for storage in seed banks
- seeds are needed from different plants, to provide a large gene pool and genetic variation
- X-rays are taken of the seeds to check for viable embryos
Describe the conditions used for the storage of seeds in seed banks, and why the seeds are stored in theses conditions
The conditions are cold and dry. This is to reduce the enzyme activity in the seeds, and to prevent the decomposition of the seeds whilst stored
Suggest how a captive breeding programme in 6 zoos could ensure that the genetic diversity is maintained within the black-footed ferret species
- A captive breeding programme is used to increase the population of the ferret species
- The zoo’s select the mates, or the zoos exchange the animals for breeding
- the zoos try to prevent interbreeding to avoid genetic drift
Suggest why no black-footed ferrets were released into the wild before 1991
- because the population of the ferret species wasn’t big enough yet
- the zoos were preparing the ferrets for their release
- some ferrets weren’t old and mature enough to be released into the wild
Suggest 3 factors that could affect the survival chances of the black-footed ferrets when they reintroduced into the wild
- competition with other ferrets
- food availability
- presence of disease
- presence of predators
In 2011, the Mount Graham squirrels were threatened by wildfires. 2 males and 2 females were taken from the wild by conservation workers.
Suggest the problems the zoo might have in trying to develop a breeding programme with these squirrels
- the population may be too small, so there’s a small gene pool, and low genetic variation
- the squirrels aren’t interbreeding
Suggest why many scientists consider that the use of protected reserves is likely to be more successful for the conservation of some animals than captive breeding programmes in zoos
- transporting the rhino’s to zoos may cause them stress
- the rhino’s are more likely to interbreed in their natural environment
- the rhinos need a lot of space, which may not be available
- in nature, food is always available
A female cheetah often mates with several different males and gives birth to two or three cubs at a time, each having a different father.
Suggest why this may be advantageous to cheetahs
- increases genetic variation
- cheetahs give birth to more than one cub to increase their chance of survival, so that they can increase the population
- mates with different mates to increase changes of pregnancy
Suggest what the effect of transferring a fertile male cheetah from one zoo to another for breeding programmes has on genetic diversity in this species
- it increases the genetic diversity, as the male cheetah is allowed to breed with different individuals
why is seed germination tested at regular intervals
- to check if the seeds are viable, and if not they are replaced by viable seeds
- allows seeds to reproduce
give two ways in which zoos help to conserve endangered species
- increase the population, and then reintroduce them into the wild
- introduce breeding programmes
- educate families about the species by giving classes
Describe how breeding programmes at zoos are designed to reduce the risk of interbreeding
- the zoos select the mates, to avoid closely-related individuals to interbreed
- exchange mates and gametes between zoos
- record the mating results
When a female light was first brought into the zoo, she showed symptoms including tremors, uncoordinated movements and aggressive behaviour. They were thought to be due to a poor diet when she was younger. Her cubs were given a better diet at the zoo, but developed the same symptoms as the mother.
Suggest what could have been the main cause of the problems in these lions.
- the cubs’ behaviour was learnt from the mother
- the behaviour was introduced by a genetic mutation, which was then passed on from the mother to her cubs
Describe and explain how global warming could affect plant species
- Global warming could affect plant species by changing its rainfall patterns, or changing their growing seasons.
- This causes a decrease of species of plants
- The temperature may be too warm for some plants
A survey was carried out, which concluded that 61% thought future generations of people could be harmed by global warming.
Suggest why the rest of the people surveyed thought that future generations of people would not be harmed by global warming
- some people may think that a solution to global warming will be found
- some people may not have known what global warming was
- some people may not want to think about the future and global warming
explain what is meant by the term succession
changes in a species over a period of time
explain what is meant by the term climax community
the final stage of a community, becoming stable and self-sustaining
Suggest why it is important to conserve rare and endangered plants
- the endangered plants could provide medicine
- to conserve their genetic variation
- ## to prevent the plant species from becoming extinct
In mountainous regions of mainland Europe, only S. europaea is found. Suggest how a distinct species of nuthatch, S. whiteheadi, has evolved in the mountainous regions of the island of Corsica
- the two bird species have been geographically isolated from each other by the mountain
- so, the S. whiteheadi has different environmental conditions, so has different selective pressures. So, different advantageous alleles, resulted from mutations, are passed on the offspring.
- the bird species evolve different adaptations, until they are reproductively isolated from each other
Suggest how environmental changes, such as those caused by global warming, are more likely to cause extinction of the S. whiteheadi (pop. = 2500), which live in the mountains, than the S. europaea, which live on mainland.
- the S. whiteheadi have smaller population, so have a smaller gene pool and less genetic variation.
- the S. whiteheadi are adapted to the cold, so will suffer when the temp. increases
- if the temp. increases, less food is available, so may starve
Explain how zoos could be important to the survival of S. whiteheadi
- introduce captive-breeding programmes to increase the population
- reintroduce them to a more protected area
