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Flashcards in trolololol Deck (35):

What word is used to describe the differences between members of the same species???



What word is used to describe a sudden change within a species?



What chemical is altered to cause a change within a species?



Define sexual and asexual reproduction?

Asexual reproduction produces clones of the parent. whereas within sexual reproduction it consists of having a male and female of the species to reproduce with eachother. within sexual reproduction, there is variation.


Explain how the body reduces its temperature when hot???

The sweat glands of the body produces a white substance - sweat. The sweat comes to the surface of the skin, this evaporates, thus, doing so evaporates with some of the bodys heat, causing it to cool down.


What gender would form if the sperm was an X chromosone?

a girl.


What gender would form if the sperm was a Y chromosone?

a boy.


how many chromosones does the sperm cell and the egg cell have??

they both have 23. together, the first cell of the baby will have 46 chromosones.


Define Homozygous/Homogote?

A Homozygote contains two identical alleles for the gene concerned.


Define an allele?

A variety of a gene


What is a Genotype?

The genetic makeup of an individual (e.g: BB, Bb, bb)


What is a phenotype?

The description of the way the genotype is manifested (e.g: Blue eyes, Red hair, Purple flowers)


Define how a dominant allele will manifest itself?

The allele that shows in the phenotype whenever it is present.


Define Heterozygous/Heterozygote

a heterozygote contains two different alleles for the gene concerned.


What did Charles Darwin analyse?

Darwin popularized the idea of natural selection. He travelled to the Galapagos islands and found that on each different island there were different types of finch birds. He studied the environment that these birds inhabited and theorized that they must have evolved differently to suit their environments, he suggested that humans and chimps(hominids) must have diverged into two different species, he claims this in "On the Origin of Species"


State 3 ways in which Carbon Dioxide is put back into the atmosphere?

Combustion (from the manufacturing of coal and oil), Respiration (via plants and animals), Soil Bacteria (they get their Carbon Dioxide from animal and plant decay)


What turns nitrites into nitrates?

Nitrifying bacteria


What turns ammonia into nitrites?



What turns dead plants and animals, as well as faeces and urine into ammonia?

decomposition by bacteria and fungi, this process is called urease.


Where can protein be found in? Give an example of what it's needed for?

Protein can be found in fish, eggs, milk, meat and nuts. It is needed for growth and repair of damaged tissue.


Where can Carbohydrates be found? Give its purpose?

Pasta, rice, bread, potatoes, sweets, cakes and biscuits. It is a supply of energy.


Where can fat be found? Give its use?

Fat can be found within Oil, butter, margarine, fried foods and red meat. Used for energy and insulation.


What is iron used for?

to make red blood cells


What is calcium used for?

we need this for strong bones and teeth.


What is water needed for?

as a solvent(things to dissolve in it)


Why do we need fibre?

In order to help our food get moved along our gut.


Give reasons as to why someone might be in favour of animal testing?

They may claim: Animal and human bodies are similar, so we need to use animals to test our drugs. Vaccines against diseases such as polio came from tests on animals. Fewer animal tests will be done in the future, as other methods are developed.


Give reasons as to why Someone might not be in favour of animal testing?

They may claim: Tests can be done using computers and by using living cells in test tubes. 95 drugs for treating strokes worked on animals but not in people. The number of tests on animals should be reduced they may cause them stress.


What is 'bioaccumulation'?

chemicals ingested by producers are passed through the food chain, the level of these chemicals increases as we go through the food chain, until when we get to the third stage consumers(carnivores) the level of these chemicals present is very high


What are the advantages of genetically modified crops?

Crops could be created that are hardy and able to grow in the tough conditions present in many developing countries. Some crops can provide biofuels. these crops could save natural resources and so conserve the environment. Disease resistant crops could increase yield.


What are the disadvantages of genetically modified crops?

Certain genes introduced into a plant may have unforeseen side-effects when consumed by humans. GM crops could spread outside farms and become weeds, which would be difficult to eradicate. If a single company had GM crops it would have complete control over the price.


State the purpose of a sensory neuron?

sensory neurons carry impulses from receptors e.g pain receptors in the skin to the CNS (central nervous system)


State the purpose of a relay neuron?

Brain/spinal cord carries impulse from sensory nerves to motor nerves.


What is the purpose of a motor Neuron?

These carry impulses from the CNS to the effector e.g. a muscle to bring about movement or gland to bring about secretion of a hormone.


What is the name given to gaps between cells?