Biology - Additional 2 Flashcards
What is respiration?
Is the process of releasing energy from glucose which goes in every cell
What is the equation of the aerobic respiration?
Glucose + oxygen > carbon dioxide + water
What does aerobic respiration do?
Builds larger molecules from smaller ones
Allows muscles to contract
In mammals and birds its used to keep their body temperature steady
In plants its used to build sugar and nitrates and others into amino acids and then proteins
What happens when you exercise?
- increases the breathing rate and makes you breath more deeply for oxygen
- increase in muscle activity so more oxygen and glucose is required also more carbon dioxide needs to be removed this happens so blood needs to flow faster
- heart beats harder
What is glycogen used for?
During exercise the muscles use glucose rapidly and need to convey glycogen back into glucose
What is wrong with anaerobic respiration?
Cannot supply enough oxygen to muscles
Respiring without oxygen this is incomplete breakdown of glucose which produces latic acid
- produces less energy
- painful and causes muscle fatigue so the muscles get tired and contact inefficiently
But they keep muscles for a little while longer
What is the equation of anaerobic respiration?
Glucose> energy + latic acid
What is oxygen debt?
Its used to repay oxygen
Keep breathing hard after you stop to get more oxygen so latic acid can be oxidised to form carbon dioxide and water
How do fossils form in rocks?
- Gradual replacement by minerals, bones don’t decay and last a long time while buried, eventually replaced by minerals as they decay they form a rock like substances shaped like the original hard part, surrounding sediments also turn rocks but fossils stay distinct inside the rock
- Casts and impressions, fossils are formed when the organism is buried in soft clay, the clay hardens around the organism as it decays leaving a cast of itself
- Preservation, places where no decay happens so there is no oxygen, moisture or in glaciers where it is too cold or in peat bogs where it is to acidic
Why don’t people know how life began?
- lack of valid and reliable
- soft bodied and soft tissue decayed completely so the fossil record is incomplete
- fossils that formed millions of years ago have been destroyed by geological rocks
Why does the extinction happen?
- cant evolve quickly enough
- environment changes
- new predator kills them all
- new disease kills them all
- cant compete with a new species for food
- catastrophic event that kills them all
- a new species develops
What is speciation?
The formation of a new species
What is an endemic organism?
When a species evolves in isolation and is only found in a place in the world
Describe the process of speciation
- A group of organisms become separated and isolated through geographical isolation
- Conditions in the other environment are different so different characteristics will become more common due to natural selection
- There is variation in the group and a allele is selected that makes them better adapted
- Better chance of survival and passing on their gene to the offspring
- This happens until they can no longer interbreed with the original group so they have become a separate species
What is mitosis?
Asexual cell division where two identical cells are formed
What is the purpose of mitosis?
To make new cells for growth and repair
Describe the process of mitosis?
- Cell gets signal to divide
- Cell duplicates its DNA
- The chromosomes line up in the centre of the cell
- Cell fibres pull the arms of the DNA apart
- The two arms of each chromosome go to opposite parts of the cell
- Membranes form around the two sets of chromosomes
- Cytoplasm divides and 2 new cells are produced
How does asexual reproduction happen?
Via mitosis
The offspring has the exact same genes as the parent so there is no variation