Biology: (Cell biology) Flashcards
(21 cards)
Define Eukaryotic cells
A complex cell, such as plant or animal cell
Eukaryotic cells contain their genetic material (DNA) in the nucleus.
In animal & plant cells
Define Prokaryotic cells
A small simple cell e.g a bacterium
In Prokaryotic cells, the genetic material (DNA) is not in a nucleus.
In bacteria
two differences in structure between prokaryotic & eukaryotic cells
eukaryotic have a nucleus proka don’t
eukaryotic have mitochondria proka don’t
magnification formula
magnification = image size / real size
name at least 3 specialised cells
sperm cells nerve cells muscle cells root hair cells phloem & xylem cells
how are sperm & nerve cells specialised
sperm cells have a long tail and streamlined head
nerve cells are long to cover distance and they have branched connections to connect to other nerve cells
Osmosis definition
the diffusion of water molecules through a partially permeable membrane, from a high concentration to a low concentration
what are chromosomes ?
coiled up lengths of DNA molecules
Each carries a large number of genes
KNOW THIS: body cells normally have two copies of each chromosome. one from mother another from father
do u know ;)
whats mitosis ?
the stage of the cell cycle when the cell divides.
multicellular organisms use mitosis to grow or replace cells that’ve been damaged
two ways embryonic stem cells could be used to cure diseases
it could make insulin producing cells for diabetes
make nerve cells for people paralysed by spinal injury
KNOW THIS: Some opponents of stem cell research argue that it offends human dignity or harms or destroys human life. Proponents argue that easing suffering and disease promotes human dignity and happiness, and that destroying a blastocyst is not the same as taking a human life
do u know ;)
magnification & resolution definition
magnification- enlarging the physical appearance or image of something.
resolution-the smallest change a measuring instrument can detect
give one metabolic reaction in cells
respiration
name two substances transported in the blood plasma
carbon dioxide, water, urea
which two blood vessels carry deoxygenated blood
pulmonary artery, vena cava
why is having more red blood cells an advantage to an athlete (3 marks)
more haemoglobin so more oxygen can be carried for more aerobic respiration of muscle cells
compare the structure of an artery with the structure of a vein (3 marks)
arteries have a thicker layer of muscle tissue
arteries have a narrower lumen
arteries don’t have valves but veins do
where in the plant stem is there a high concentration of dissolved sugars
the phloem
What are the four chambers of the heart
Right atrium, right ventricle
Left atrium, left ventricle
Why does the heart have valves
To make sure the blood flows in the right direction
