General Past Paper Corrections Flashcards
Give one function of the small intestine.
Produces protease, amylase and lipase to complete digestion
It also absorbs nutrients out of the alimentary canal and into the body
What is ingestion?
Taking food in mouth and swallowing
What is digestion?
Breaking down into smaller pieces and molecules
What is absorption?
Taking small molecules from the gut into the blood
What is assimilation?
Molecules gained from food used to build new ones - cells and tissues
What is egestion?
Passing indigestion food through the anus
What is one function of the pancreas?
Secretes amylase
Give an example of diffusion in the lung of the mammal
Oxygen moves from the alveoli to the blood
Give an example of osmosis in the kidney of a mammal
Glucose which moves from the nephron to the blood
Give an example of active transport in a flowering plant
Uptake of mineral salt which moves from the salt to the cytoplasm in a root hair cell
What is the function of lipids?
To provide energy and store it, and insulate
What is the vitamin C deficiency problem?
Scurvy
What is vitamin D deficiency problem?
Rickets
What is the deficiency problem of calcium?
Rickets
What are the 2 products of lipid digestion?
Glycerol and fatty acids
What contains RNA strands?
Virus’s
What is the definition of nutrition?
Taking in food required to live
What is the definition of growth and development?
Making new cells
Where does peristalsis occur?
The whole alimentary canal
Name one carbohydrate found in plants that contains carbon
Starch
Why are nitrates needed to help plants grow?
To make amino acids and proteins
turns yellow if there’s not enough
Why are phosphates needed for plants?
To make DNA and cell membranes for respiration
Why is potassium needed in plants?
To help enzymes for respiration and photosynthesis
What are the effects of lack of phosphates in a plant?
Poor root growth and purple leaves
What are the effects of not enough potassium in a plant?
Poor flower and fruit growth
Why is magnesium needed in a plant?
Only needed in small amounts to make chlorophyll
How do mineral ions enter plants?
Through root hair cells by active transport, and transport through the xylem
What are the effects of fertilisers washing into rivers? (7)
Leaching occurs due to nitrates spilling
Algal blooms
Light can’t get in to allow plants to photosynthesise
The plants die
Saphratrophic nutrition - bacteria feed on the dead
Increases BOD
Fish die
What happens to the suns radiation when it enters the earth? (Greenhouse effect)
It is reflected off the earths surface, absorbed then re emitted
What are greenhouse gases made up of?
Water vapour, carbon dioxide and methane
What are some possible consequences of increase in greenhouse gases? (5)
Global warming- earth warms up Habitat change Desertification Species loss More flooding
What is nitrification?
When ammonia is converted to nitrates by nitrifying bacteria
Why do farmers grow legume plants in their fields? (5)
Legumes contain nitrogen fixing bacteria in the root nodules
Fix nitrogen gas into ammonia
Ploughing causes clover plants to decompose
Releasing ammonia
Increase yield
There are mineral ions and nutrients in the soil
What is meant by the term double helix?
Two strands linked together
Which hormone repairs uterus lining?
Oestrogen
Which hormone maintains uterus lining?
Progesterone
What is the role of the placenta?
Secretes progesterone so lining stays thick
Prevents embryo from aborting
What is the role of the amnion sac?
Secretes amniotic fluid
Protects embryo against bumps and jolts
Encloses embryo
Once the egg is released where does it go?
Travels down oviduct to the uterus
What is the role of corpus luteum?
Produces progesterone
How do hormones travel from the ovary to the uterus?
In the blood stream
How many chromosomes are there in a body cell of the male fetus?
46
What is the role of meiosis?
To produce gametes
Where does meiosis occur?
In the ovaries and testes or ovary and anther of a plant
How many chromosomes are produced in meiosis?
Half the number - haploid
What is the purpose of mitosis?
For growth and repair damaged tissue
How many chromosomes are produced in mitosis?
Diploid - 1 pair of each chromosome in the nucleus
Does meiosis produce genetically identical gametes?
No
Does mitosis produce genetically identical cells?
Yes
How many chromosomes are there in a human body?
46
What are the advantages to a sexual reproduction?
Reproduce v. quickly with no partner needed
Numbers double each generation
What are the disadvantages to asexual reproduction?
No variation
What is selective breeding and what are 2 examples of its use? (5)
Desirable characteristics
Prevent breeding with other individuals
Repeated for many generations
Example- cattle for milk yield
- wheat for shortened stem lengthHow can bacteria be genetically modified to produce human insulin? (5)
Human insulin cut from human chromosomes Using restriction enzymes Plasmid cut open Making sticky ends Using some restriction enzymes
What is the role of insulin in the body?
Tells liver to take in glucose and covert it to glycogen
Lowering blood glucose levels
Describe the stages of cloning in mammals (6)
Egg/ovum removed
Nucleus removed
Nucleus taken from body cell and inserted into ovum
Encleated ovum fused with body cell using electricity
Cell divided by mitosis
Embryo implanted into uterus of surrogate mother
What is a gene?
A code for a certain protein which controls processes in the body
What is an allele?
Alternative form of a gene
What is a dominant allele?
Expressed when there’s a recessive allele present
Version of a gene
Why is the number of people who have a rare condition low even though it’s a dominant condition? (3)
It’s very rare
Makes individuals less likely to reproduce
So becomes less common every generation
What are 2 advantages to micropropagation?
Can produce large quantities
Could lose gene in sexual reproduction otherwise
