Unit 2 : Organisation of the Organism Flashcards
6 Features that all eukaryotic cells / animal cells have
cell membrane, cytoplasm, nucleus, mitochondria, ribosome, endoplasmic reticulum
Define Cell Membrane
controls movement in and out of cells
Define Cytoplasm
jelly like substance which is the site of most chemical reactions in the cell
Define Nucleus
spherical structure that contains cell’s DNA/genetic code and controls activities of the cell and cell division
Define Mitochondria
where aerobic respiration happens
Define Ribosome
allows protein synthesis in the cytoplasm
Define Endoplasmic Reticulum
studded with ribosomes, it looks rough under the microscope
3 Features that only Plant Cells contain
vacuole, cell wall, chloroplasts
Define Vacuole
cell sap to keep cell turgid
Define Cell Wall
rigid to hold the shape of the cell, strengthens the cell
Define Chloroplasts
contains chlorophyll, which absorbs light energy for photosynthesis
2 Features that Prokaryotes Lack
mitochondria and a true nucleus
Define Plasmids
small, circular rings of DNA in the cytoplasm with extra genes outside the chromosomal DNA
2 Specialised Features of a Root Hair Cell
- absorbs water + dissolved mineral ions from soil
- has hair like projection to provide larger area / larger surface area to volume ratio for absorption to happen
1 Specialised Feature of Ciliated Cells
has cilia ( hair-like structure ) that helps with the movements of mucus up to the throat where it can be swallowed
1 Specialised Feature of Palisade Mesophyll Cells
packed with chloroplasts and tall, elongated cells packed together to increase surface area
2 Specialised Features of eurones
- long extensions of neurons called dendrites are axons that help in sending impulses
- dendrites receive signals and impulses while the axon sends signals to other neurons or tissue
3 Specialised Features of Red Blood Cells
- biconcave shape to maximise surface area to absorb oxygen.
- thin cell membrane so gases easily diffuse through
- no nucleus to increase space for more oxygen
2 Specialised Features of Sperm Cells
- acrosome is a cap on the head that assists with penetration of the jelly coating of the ovum
- flagellum is the tail of the sperm. It undulates to help in moving and navigating through the female reproductive system
2 Specialised Features of Egg Cells
- large energy stores / nutrients for the growing embryo
- jelly coating ( zona pellucida ). after one sperm cell penetrates the initial jelly coating, the coating become impenetrable to other sperm cells
What are the Levels Of Organisation
cells - tissue - organ - organ system - organism
Define Cells
the basic structural and functional unit of all forms of life
Define Tissue
a group of cells with similar structures and hich work together to carry out a shared function
Define Organ
a group of tissues which work together to carry out specific functions
Define Organ Systems
a group of organs with related functions which work together to carry out body functions
Formula for Magnifiction
magnification = image size ÷ actual size
Define Magnification
the degree to which the size of an image is larger than the image itself
Formula for Light Microscope
eyepiece magnification x objective magnification