GCSE basic Knowledge Flashcards
What does protease catalyse the breakdown of?
Proteins into amino acids in the stomach and small intestine
Where is protease produced?
The stomach, pancrease and small intestine
Where is lipase produced?
The pancreas and small intestine
What does lipase catalyse the breakdown of?
Lipids (fats and oils) to fatty acids and glycerol
Where is soluble food absorbed?
Small intestine
Where are stem cells found?
In the human embryo and in adult bone marrow
How is a leaf cell adapted to carry out photosynthesis?
The leaf has mesophyll tissue. The mesophyll cells contain chloroplasts which can photosynthesise
How should you place a quadrat to investigate the distribution of organisms? How?
Choose places randomly. Do so by throwing the quadrat over back, eyes shut, grid with random numbers
Name three substances used for storage in plants
Starch, fats and oils
What is an allele?
Genes controlling the same characteristic
What happens in the circulatory system when you exercise?
The heart rate increases and the blood vessels supplying the muscles dilate. This allows more blood containing oxygen and glucose to reach muscles
What does a gene code for?
The order of amino acids in a protein
Muscles store glucose as glycogen. What happens to glycogen when you exercise?
It is converted bacteria to glucose for use
What is mitosis?
Two identical cells being produced from the original cell. A copy of each chromosome is made beforehand
Where is amylase produced?
Salivary glands, pancreas and small intestine
What does amylase catalyse the process of?
The digestion of starch into sugars in the mouth and small intestine
What happens in the large intestine?
Water is absorbed from the undigested food, producing faeces
What is meiosis?
4 sex cells are made each with a single set of chromosomes. A copy of each chromosome is made beforehand and the cell divides twice
What are the advantages of using isomerase immobilised in a column of beads? (3 reasons)
The product is not contaminated. The enzyme can be reused. Continuous flow process possible
In which organs does digestion occur?
Stomach and small intestine
Which scientist worked out how characteristics are inherited?
Gregor Mendel
What is meant by genetic variation?
The wide range of alleles that control the characteristics in a population
Why would manufacturers of slimming food put fructose instead of glucose in dies sweets?
You use less fructose to achieve the same sweetness
What is the role of a stem cell?
To change into other types of cell for the body to use
What is the “oxygen debt”?
The extra oxygen required to break down the remaining lactic acid to CO2 and water
Why does each chromosome become two strands before the cell divides?
One copy of each chromosome to each offspring cell
What is osmosis?
The diffusion of water. No energy required unlike active transport
Which enzyme is used to convert glucose into fructose?
Isomerase
What does a cell membrane do?
It controls the movement of materials in and out of the cell
Scientists are uncertain about how life started on earth. Explain why.
There is a lack of valid evidence. Because the early organisms’ remains were destroyed by geological action.
What is speciation?
When two populations can no longer successfully interbreed.
Why do reactions take place faster when it’s warmer?
At higher temperatures, the molecules move around more quickly and so collide with each other more often and with more energy.
What is genotype?
The genetic make-up. The alleles the individual inherits: DD, Dd or dd.
What does the liver produce?
Bile. It is squirted into the small intestine to neutralise the stomach acid. Makes the condition slightly alkaline.
If a cell has many ribosomes, what could its function be?
Gland cells to produce enzymes.
Where is the genetic material kept in a bacterial cell since it does not have a nucleus?
Cytoplasm.
What is phenotype?
Physical appearance of the characteristic, i.e, dimples or no dimples, eye colour…
Which sex chromosome are found in human males?
X and Y (XY)
What is the substance produced by the stomach to make the conditions the right pH (acidic) for enzyme action?
Hydrochloric acid (HCl)
What are the stages in Speciation?
- Isolation of the two groups. 2. Genetic variation in the groups; alleles are selected which give an advantage. 3. Interbreeding no longer possible.
What is tissue culture?
Tissue culture is taking small groups of cells from part of a plant and growing then under special conditions. It’s more expensive. Can be used to produce large numbers of rare or top quality plants.
What is a detritivore?
Detritivores are heterotrophs that obtain nutrients by consuming detritus (decomposing plant and animal parts as well as feces).
Give an example of a detritus feeder
Worm
What are the main kingdoms of living organisms?
The main kingdoms are: the plant kingdom, the animal kingdom, the kingdom that contain the microorganisms
Name a quick, cheap way of cloning plants
Taking cuttings from mature plants is a quick and cheap way of cloning
Why is it more difficult to successfully clone animals than plants?
Animal embryos must be split into groups of cells and each group is transplanted into a host “mother”. There have to be enough hosts and some embryos may die during development. It also takes longer for animals to develop.
What is asexual reproduction?
Asexual reproduction does not involve the fusion of gametes. All the genetic information comes from 1 parent. There is little variety and the offsprings are called clones.
What is sexual reproduction?
Sexual reproduction involves the fusion of gametes. There is a mixing of genetic information so the offspring show variation. The offspring cannot be identical.
What are chromosomes?
Chromosomes are thread-like structures found in the nucleus of a cell. The carry the genes.
What do genes control?
Genes control the development of characteristics such as eye colour or thumb shape.
