whole of biology paper 1 Flashcards
what are in both plant and animal cell and what are their functions?
- cell membrane (control what goes in and out of cell)
- mitochondria (respiration)
- nucleus (stores dna)
- ribosomes (proteinsynthesis)
- cytoplasm (reactions happen)
what else, not in an animal cell, is in a plant cell and what is their functions?
- cell wall (keeps structure)
- vacuole (cell sap)
- chloroplasts (where photosynthesis takes place)
what are in a bacterial cell and what are their functions?
- cell membrane (control what goes in and out of cell)
- cytoplasm (reactions happen)
- chromosomal dna
- flagella (movement)
- ribosomes (proteinsynthesis)
- cell wall (keep structure)
centimetre = ?
millimetre= ?
micrometer= ?
nanometre= ?
picometer= ?
centimetre = 1x10^-2
millimetre= 1x10^-3
micrometer= 1x10^-6
nanometre= 1x10^-9
picometer= 1x10^-12
what do different cells specialise into different things through?
differentiation
what is the equation for magnification?
image size= actual size x magnification size
fill in the blanks: (how enzymes work)
the __ fits onto the __ __ of an ___ making an __ __ __ which leads to the making of __
the substrate fits onto the active site of an enzyme making an enzyme substrate complex which leads to the making of products
how does temperature affect the enzyme activity?
when the temperature is low, the enzyme activity is low due to not enough energy
when the temperature gets higher, the enzyme activity reaches the optimum (the best)
when the temperature gets too hot, the enzyme activity decreases as the enzyme has denatured
how does pH affect enzyme activity?
if the pH is too low or too high, the enzyme activity decreases because the enzyme has denatured
if the pH reaches the optimum, the enzyme activity is at its best
what does an enzyme catalyst do to a reaction?
speeds up the reaction
how does substrate concentration affect enzyme activity?
as the substrate concentration increases, the enzyme activity also increases but soon it stops increasing due to the active site being filled up
fill in the blanks:
lipase breaks down __ into __/__ which are made in the __ and work in the __ __
lipase breaks down fats into fatty acids/glycerol which are made in the pancreas and work in the small intestine
fill in the blanks:
protease breaks down __ into __ __ which are made in the __ and work in the __ __
protease breaks down proteins into amino acids which are made in the pancreas and work in the small intestines
fill in the blanks:
amylase breaks down __ into __ which are made in the __ and work in the __ __
amylase breaks down starch into sugars which are made in the pancreas and work in the small intestines
define diffusion
diffusion is the movement of particles from a high concentration to a low concentration
define osmosis
osmosis is the movement of water particles from a high water concentration to a low water concentration through a semi-permeable membrane
define active transport
active transport is the movement across a membrane from a low to high concentration
what is cancer and what are the risk factors?
cancer is uncontrolled cell mutation
risk factors: smoking, diet, sun, unprotected sex
what are the uses of stem cells?
- treat parkinson’s disease
- organ failure
- bone and spinal injury
what is the method for stem cells?
- nuclei removed from egg cell
- nuclei from patients cell inserted into empty egg
- egg starts to develop into embryo
- stem cells removed from embryo and turned into new cells
what does the central nervous system consist of?
the brain and the spinal cord
what are the advantages and disadvantages of sexual and asexual reproduction?
sexual reproduction:
advantages- genetically diverse, disease less likely to infect the whole population
disadvantages- need a mate, longer reproduction cycle
asexual reproduction:
advantages- no mate required, quicker reproduction
disadvantages- genetically identical, disease will wipe out population
what are the processes of mitosis?
- interphase: dna gets replicated
- prophase: chromosomes pair up and condense
- metaphase: chromosomes meet up in the middle of the cell
- anaphase: chromosomes move apart to each end of the cell
- telophase: nucleus reforms
- cytokinesis: cytoplasm splits
what is the difference between mitosis and meiosis?
mitosis: produce 2 identical daughter cells, diploid, used for growth and repair
meiosis: produces 4 different daughter cells, haploid, used for sexual reproduction (gametes)
extracting dna from fruit (practical):
- mash up the fruit
- add salt water and detergents
- leave for 15 mins at 60 degrees
- filter
- add iced ethanol
- dna floats to the top
what are the complimentary bases for dna?
c and g
a and t
structure of dna:
- double helix structure into a chromosome which is in the nucleus
- sugar phosphate backbone
- 23 pairs, 46 in total, one from each parent
define gene
a stretch of dna which codes for a characteristic
define genome
all genes in a body
define gamete
a sex cell
define chromosome
bundled up dna
define alleles
different versions of genes
define dominant
only need one gene for this characteristic to pass down
define recessive
you need two identical genes for this characteristic to pass down
define homozygous
genes are the same
define heterozygous
genes are different
define genotype
what genes you have
define phenotype
what characteristics you have influenced by the environment, diet and exercise
what is selective breeding and what are the advantages and disadvantages?
selective breeding: breeding an animal for a particular characteristic
advantages: desired characteristic being made
disadvantages: may lead to health problems, lack of genetic diversity
define natural selection
individuals with characteristics which make them better suited to the environment and more likely to survive, reproduce and pass on their genes
what are the evidences for evolution?
- fossils which can show chnages and how animals are related
- bacteria
what is the definition of health?
the physical, mental and social well-being of a person (affected by diet, exercise, community)