Jan/Feb bio test Flashcards
genes, cloning, ev. trees, natural selection, that kinda thing yk
Name all 5 receptors
Eyes, ears, nose, hands, mouth
Name the 2 coordinators
brain, spinal cord
name the 2 main effectors
muscles, glands
What are reflexes?
special type of nervous impulse which is automatic and is designed to protect you.
reflexes- They travel through a ______ _______ in the spine called a ______ ______. This makes them faster than normal impulses.
reflexes- they travel through a third neurone in the spine called a relay neurone. This makes them faster than normal impulses.
What are evolutionary trees used to show?
Evolutionary trees show how recently species branched from one another, how closely related different species are, and what different species evolved from.
What is natural selection also known as?
Survival of the fittest
Explain an example of natural selection to do with moths.
There were white moths that blended in with the white trunks of trees to protect themselves from birds. When the trees changed black, they were spotted more easily and their population went down, whereas black moths’ population went up.
Why might a species become extinct?
When they can’t adapt to a changing environment, disease, poaching.
The _______ system releases chemical messages called _________.
The endocrine system releases chemical messages called hormones.
Give an example of the endocrine system in action
The blood sugar level is monitored by the pancreas, causing hormones to be released and sent to the liver
When a new species is discovered, it is given a binomial name. What is a binomial name?
A name with two parts, for example: a tiger = ‘panthera tigris’.
How is a binomial name given to a new species?
The first name refers to the genus and the second name refers to the species.
Explain speciation
Species that have been geographically isolated may meet again. If they meet again and they cannot breed to produce fertile offspring then the species has changed so much during separation that they are now separate species
Genes are made of _____ that codes for certain _________.
Genes are made of DNA that codes for certain characteristics.
How many PAIRS of chromosomes are in each nucleus of a human cell?
23 pairs
Dominant genes will… (finish the sentence)
Dominant genes will ensure a certain characteristic appears in an individual.
When will recessive genes appear?
Recessive genes will only appear when the dominant genes aren’t present.
A ______ square is a useful way of working out the _________ of ________ a particular gene.
A Punnett square is a useful way of working out the probability of inheriting a particular gene.
A man and a woman want to have a baby. The man (Dd) has polydactyly and the woman (dd) does not. What is the probability that the child will have polydactyly?
There is a 50% chance that the child will have polydactyly. You could use a Punnett square to help next time if you need to.
State some negatives of selective breeding:
Reduction in gene pool, pathogens could wipe out the whole species, etc.
State some positives of selective breeding:
More money, weaker organisms are wiped out, etc.
Genetic engineering is the process of… (finish the sentence)
Genetic engineering is the process of cutting a useful gene from one organism and inserting it into another.
What are stem cells?
Stem cells are unspecialised cells that can differentiate into almost any other type of cell, including bone marrow, blood cells, and muscle cells.
Why might stem cell treatment be better than an organ transplant?
Less risk of rejection, shorter waiting time because you don’t have to wait for an organ donor.
Why might an organ transplant be better than stem cell treatment?
Stem cell treatment is very expensive, there is some risk involved with stem cells because the use of them is very new, stem cells are difficult to obtain. 60% of people survive for ten more years after an organ transplant.
State some advantages of cloning.
Clone excellent examples of animals, farmers can make more money, you know what features your animals are going to have.
State some disadvantages of cloning.
Reduces genetic variation, some people view it as “playing God”, requires scientists and special equipment which might be expensive or difficult to acquire.
What is the definition of biodiversity?
Biodiversity is the existence of a wide variety of plants and animal species living together in their natural environment.
A black spider monkey is considered an endangered/vulnerable animal. Why might this be?
A low population, high risk of extinction, the amount the population has decreased in the last few years.
Extras-
The black spider monkey specifically has a population of around 250 and has fallen by 30% in the last 45 years, but it isn’t high risk enough to be considered critically endangered like amur leopards and mountain gorillas, for example.
