Cell Biology Flashcards
How big are the three types of cells?
Animal cells: 0.01-0.05mm
Plant cells: 0.01-0.1mm
Bacterial cells: 0.0002-0.002mm (0.2-2um)
Difference between coarse, objective and fine focus lenses?
Coarse Focus: Moves the stage up and down
Objective lens: Attached to the eyepiece lens and have different magnifications
Fine Focus: Adjusts focus of the specimen
Equation for magnfication
Image Size/Object size
Method to investigate cells with a light microscope
1.Rotate objective lens to lowest power
2.Place a dyed slide onto the stage
3.Turn coarse focus until as close as possible to the objective lens
4.Record an image
5. Rotate the objective lens, adjust focus knobs and repeat.
What piece of equipment is used to measure the scale of cells?
An eyepiece graticule
How do eukaryotic vs prokaryotic cells reproduce?
Eurkaryotic: Mitosis
Prokaryotic : Binary Fission
How is a supermarket cell adapted to its function?
Has a head containing an acresome that allow it to burrow into the egg
Head contains its haploid nucleus
Midpiece contains many mitochondria to release energy required for swim
Flagella allows movement
How is a nerve cell adapted for its function?
Long and slender so it can stretch the entirety of the nervous system.
Has extensions and branches to communicate with other nerve cells, muscle and glands.
Nerve cell is insulated by myelin, speeding up nerve.
How are muscle cells adapted for their function?
Cause filaments of protein that slide over one another for muscle contraction
Many mitochondria for energy for muscular contraction
How are root hair cells adapted for their function?
Large surface area to provide contact with soil water
Thin walls for active transport/osmosis
How is a phloem cell adapted for its function?
Translocation is bidirectional
Phloem cells are alive
How are xylem cells adapted for their function?
Lignin strengthens their walls
Transpiration is unidirectional
Xylem cells are dead
How many chromosomes does the human body have, and in how many pairs?
46, in 23 pairs
When do cells divide? [2]
When:
An organism grows
An organism is damaged and requires the production of new cells
What does the xylem carry vs the phloem? [2]
Xylem carries water and dissolved mineral from the roots around the plant.
Phloem transports products of photosynthesis, including sugars and amino acids from the leaf to where they are needed.
What is the equation for calculating time spent in a stage of the cell cycle
(Observed number of cells at that stage / total number of cells observed)
x100
Define a stem cell [1]
A cell that has not gone through differentiation
How can stem cell treatments be used in the medical field [3]
Therapeutic cloning can be used
To treat conditions like diabetes and paralysis
As these cells will nit be rejected by the recipient
Where can stem cells be found in humans? [2]
In embryos
In bone marrow
Where are stem cells found in plants and how do they differentiate? [2]
Stem cells can be found in meristem tissue
Stem cells can differentiate to produce any form of plant cell at any stage in the plants life
What are the uses of harvesting plant stem cells? [2]
They can be cloned to save rare plants from extinction
They can be cloned to make crops that are resistant to diseases and pests
Name different types of cell within the leaf and their functions [6]
Palisade Mesophyll: carries out photosynthesis
Spongy Mesophyll: allows for efficient gas exchange
Stomata and guard cells: controls rate of gases moving in and out of the leaf
Waxy cuticle: reduces water loss out of the leaf
Upper epidermis: Allows light through to the palisade mesophyll
What are the clinical issues involved with therapeutic cloning? [2]
There is no guarantee how successful the treatment will be
There is a difficulty finding stem cell donors
Describe the process of therapeutic cloning [4]
The nucleus is discarded from a donor egg cell
A cell from the patient transfers its nucleus to the egg cell
The cell is stimulated to divide and forms an embryo
After 4/5 days, the stem cells are harvested from the embryo
