b1 Flashcards
name the main organelles in an animal cell and their functions
nucleus - controls genetic information and controls cell activities
ribosomes - site of protein synthesis
cell membrane - controls movement of substances in and out of the cell
cytoplasm - gel where chemical reaction takes place
mitochondria - site of aerobic respiration and energy release
name the main organelles in a plant cell
nucleus - controls genetic information and controls cell activities
ribosomes - site of protein synthesis
cell membrane - controls movement of substances in and out of the cell
cytoplasm - gel where chemical reaction takes place
mitochondria - site of aerobic respiration and energy release
cell wall - made of cellulose to strengthen the cell
permanent vacuole - filled with cell sap to keep cells rigid
chloroplast - site of photosynthesis
what is the relative size of a bacterial cell
0.2 micrometres to 2 micrometres
how is genetic material found in eukaryotic cells
found in a chromosome of dna
how is genetic material found in prokaryotic cells
in plasmids that float freely
what is cell differentiation
cells that have specific genes to carry out specific functions
what is cell differentiation
cells that have specific genes to carry out specific functions
give the function and specialisation of the following: red blood cell nerve cell root hair cell sperm cell egg cell
red blood cell - carry oxygen/co2 around body - haemoglobin to stick to oxygen, biconcave to travel freely
nerve cell - send n collect electric messages - long n thin to send messages faster, myelin sheath to stop electrical signal travelling down axon
root hair cell - absorb water from soil - long n thin for larger surface area, thin cell wall for allowing water through
sperm cell - fertilise egg - flagellum fro swimming, mitochondria for respiration
egg cell - be fertilised by sperm - mitochondria for energy release, half of mothers genes
list the organisational hierarchy
cell, tissue, organ, organ system, organism
describe the differences in magnification and resolution between electron and light microscopes
magnification light - 1500 electron - 500,000 resolution light - 250nm (nanometre) electron - 0.25nm electron has better resolution
define binary fission
asexual reproduction - separation of body into 2 new bodies
explain how to prepare an uncontaminated culture
sterilise incoulating loop using flame
lift n tilt lid of the petri dish - do not fully remove
after the inoculation the lid should be secure down
what is the formula for magnification
image size/actual size
define binary fission
asexual reproduction - separation of body into 2 new bodies
what is mitosis
Mitosis is a process where a single cell divides into two identical daughter cells (cell division)
what is the main purposes for mitosis
embryo development seed germination plant growth repairing tissues replacing loss blood cells
explain steps of mitosis
interphase - parent cell has a nuclear membrane and chromatin
prophase - the dna in chromosomes and their copies condenses and nuclear envelope breaks down
metaphase - sister chromatids line up in the middle of the cell.
anaphase - chromosomes are pulled to different ends of the cell
telophase - new nuclear envelopes form and chromosomes decondense
cytokinesis - the 2 identical cells form as the parent cell divides
recall cell cycle
cells grow in size, produce dna n synthesise proteins temporary resting phase check point cell continues to grow dna replicates cell grows, more proteins produced check point division of cell begins check point mitosis takes place
define a stem cell
stem cells are the body’s raw materials — cells from which all other cells with specialised functions are generated
undifferentiated
recall the origin of stem cells
sperm n egg - fertilised egg - embryo - foetus - stem cell in foetus - stem cell in baby - stem cell in adult
list potential healing benefits of adult stem cells
paralysis parkinsons muscle loss skin renewal vision loss neural dysfunction joint n organ repair metabolic disorders cardiovascuar repair
give benefits of using stem cells
some can be frozen for later use (umbilical cord)
replaced damaged cells
can grow into any type of cell
low chance of rejection if from the same person
what is a cell
image result for what is a cell
Cells are the basic building blocks of all animals and plants. Inside cells are various structures that are specialised to carry out a particular function
give ethical issues of stem cells
embryos can be produced just for stem cell extraction
costs a lot to store cells
some can contain serious cancer causing mutations
stem cell transplants can be rejected by immune system
can be expensive
what is a tissue
Tissue is a group of cells that have similar structure and that function together as a unit
what is an organ
collection of tissues that structurally form a functional unit specialized to perform a particular function
what is an organism
An organism is an individual form of life that is capable of growing and reproducing, and have one or more cells.
define diffusion
movement of molecules form an area of high to low concentration
list factors that affect diffusion
concentration - more particles means slower process
temperature - high temperature is quicker (more energy)
surface area of membrane - more chances of particles entering cell
give an example of diffusion in the human body
digestion - food absorbed from small intestine to bloodstream
villi increase surface area for easier diffusion
gas exchange in lungs
urea for excretion in kidney
what is osmosis
Osmosis can be best defined as the movement of water across a semipermeable membrane from an area of high water concentration to an area of lower water concentration
dilute to concentrated
give the 3 solutions of different concentrations
what type of concetration would a plant cell favour
hypotonic
define active transport
movement of substances against a concentration gradient (low to high) through a partially permeable membrane
requiring energy from respiration
list uses for active transport in plants and animals
absorption of ions into root hair cells
absorption of small amount of sugar into the villi
what is the difference between diffusion osmosis and active transport
In diffusion and osmosis, substances move down a concentration gradient. However, active transport moves substances against a concentration gradient.Conversely, diffusion and osmosis are passive processes, so they happen without the need for energy.
Give examples of diffusion in the body and plants
- gas exchange in the lungs (alveoli)
- waste product (urea) from the cells into the blood plasma for excretion
- co2 diffuses into the leaf for photosynthesi
Give examples of active transport in the body and plants
- uptake of glucose by epithelial cells in the villi of the small intestine
- uptake of ions from soil water by root hair cells in plants
- Sugars from photosynthesis moving from leaves to fruit
- Amino acids moving along the human intestinal tract
Give examples of osmosis in the body and plants
- taking water from waste in the excretion process
- water absorption via fishes gills
- digestion in small and large intestine
list factors that affect osmosis
concentration gradient light/dark temperature surface area pressure
list factors that affect active transport
