Flashcards in Cell Structure Deck (60):
What is a cell?
The smallest structural unit of life capable of functioning and replicating independently
Name the parts of 5 parts of an animal cell?
Ribosomes, mitochondria, nucleus, cytoplasm, cell membrane
Name the 7 parts of a plant cell?
Ribosomes, mitochondria, chloroplast, vacuole, nucleus, cell membrane, cell wall
Function of the nucleus?
Holds cell DNA on chromosomes and controls activities of the cell
Function of the cytoplasm?
Where chemical reactions occur
Function of the mitochondria?
Site of respiration/energy release
Function of ribosomes?
Site of protein synthesis
Function of the cell membrane?
Controls what goes in and out of the cell
Function of the vacuole?
Contains cell sap and supports the cell
Function of chloroplasts?
Contains chlorophyll which absorbs light for photosynthesis
Function of the cell wall?
Strengthens and supports the cell
5 characteristics of a eukaryotic cell?
Has a nucleus, has membrane bound organelles, dna held on chromosomes in the nucleus, has a membrane present, cell wall if present is made of cellulose
5 characteristics of a prokaryotic cell?
No nucleus, circular loops of DNA within the cytoplasm, man be one or more small rings of DNA (plasmids),cell wall is present is made of murien
Which is bigger prokaryotic or eukaryotic?
How many times bigger is 1 order of magnitude?
10 times bigger
5 characteristics of a light microscope?
Can magnify up to 2000 times, relatively cheap, can magnify live objects, reliant on a light source, 2D image produced
6 characteristics of an electron microscope?
Expensive, higher magnification, more detailed image, magnify up to 2 million times, beams of electrons instead of light, 3D image produced
Equation for magnification?
Size of image = magnification x size of real object
How is a root hair cell adapted to its function?
Large surface area to absorb water
How is a ciliated epithelial cell adapted to its function?
Has many hair like structures which brush away mucus
How is a sperm cell adapted to its function?
Head is streamline and has a tail which helps it to swim to the egg
How is a palisade cell adapted to its function?
Has lots of chloroplasts to carry out photosynthesis
How is a nerve cell adapted to its function?
Lots of dendrites make connections to other cells, long axon to carry impulses from one place to another
How is a red blood cell adapted to its function?
Large surface area for oxygen to pass through, haemoglobin joins to the oxygen
How is a xylem adapted to its function?
Waterproof walls make sure the plant does not fall over when the water is being carried from the roots to leaves
How is a phloem adapted to its function?
Companion cells keep it alive and provide the energy needed to transport food from the leaves to the rest of the plant
What is differentiation?
When organisms develop and cells become specialised for a particular function
What is a gene?
A shaker section of DNA which codes for a particular characteristic such as hair or eye colour
What is a gamete?
What is fertilisation?
Process of a sperm and egg meeting
What is a chromosome and how many do we have in our body cells?
A long strand of DNA wrapped up in a helical structure, 46 in our body cells
Whah is a zygote?
Fertilised egg cell
Is an XX chromosome male or female?
Is an XY chromosome male or female?
What is a stem cell?
An undifferentiated cell which is able to differentiate into specialised cell types, they can divide
Which two sources do stem cells commonly come from and where are they found?
Embryos formed in blastocyst phase of embryological development and adult bone marrow , found in different types of tissue
5 uses of stem cells?
To replace or rejuvenate damaged tissue, to make more specialised tissue which has been lost due to injury or disease, treat blood based diseases, test different drugs, prevent plants becoming extinct
Why is human embryonic stem cell research ethically and politically controversial?
It involves the destruction of human embryos
What type of cell is one which contains 23 pairs of chromosomes?
Why do we need cell division? (3 reasons)
Allow growth, replace worn out cells, repair damaged tissue
What is diffusion?
The movement of particles from a high concentration to a low concentration
What is osmosis?
The overall movement of water through a partially permeable membrane from a region of high water concentration to low water concentration
What is active transport?
The movement of particles from a low concentration to high concentration
Which process needs carrier proteins in the cell membrane?
What happens to the rate of diffusion if the temperature increases?
When water enters a plant cell and pushes on the cell wall causing it to swell
When water leaves a plant cell and the cell contents shrink and the cell membrane pulls away from the cell wall
Define partially permeable
A membrane which allows some substances to pass through but not others
Concentration of the solutes in the solution surrounding the cell is higher than inside the cell
Concentration if solutes surrounding the cell is lower than inside the cell (more water)
The liquid in which a substance dissolves
The substance which dissolves in a liquid
When red blood cells gain water, swell and burst in a more dilute solution
When red blood cells lose water and shrink in a more concentrated solution
Involving the kidneys ensures that the concentration of the blood stays about the same as the concentration of the cell contents in terms of water
Contains a high concentration of water molecules
What happens to red blood cells in a hypotonic solution?
They gain water and swell becoming turgid
What happens to red blood cells in a hypertonic solution?
They shrink and become wrinkled
What is embryo screening?
A method where embryos from presumed chromosomally normal genetic parents are tested for abnormalities, involves removing a cell from an IVF embryo to test it before transferring it to the uterus