B1, Cells Flashcards
what is cytoplasm
gel-like substance where most of the chemical reactions happen, contains enzymes that control these chemical reactions.
what is the cell membrane
holds the cell together and controls what goes in and out
what are chloroplast
where photosynthesis occurs
what are ribosomes
where proteins are made in the cell
what is the nucleus
contains genetic material that controls the activity of the cell
what is the cell membrane
holds the cell together and controls what goes in or out
what is the permanent vacuole
a weak solution of sugar and salts
contains cell saps
found in plant cells
what are the different types of the cell called
subcellular structures
what is an organelle
structure in a cell
why do multicellular organisms use mitosis
for growth and to replace damaged cells
name a substance transported out of a cell by diffusion
carbon dioxide
which part of the cell provides energy
mitochondria
name 5 subcellular structures that both plant and animal cells have
- nucleus
- cell membrane
- mitochondria
- cytoplasm
- ribosomes
3 things plant cells have that animal cells don’t
- cell wall
- permanent vacuole
- chloroplast
what is cell differentiation
process by which a cell changes to become more specialised for it’s job
3 ways a sperm cell has become more specialised for swimming to an egg cell
- long tail
- streamlined head
- carries mitochondria to provide energy
- enzymes in its head to break through egg cell membrane
what is osmosis
the movement of water molecules across a partially permeable membrane from a lower to a higher solute concentration
what is a difference between active transport and diffusion
active transport requires energy from respiration
what is active transport
Active transport is a process that is required to move molecules against a concentration gradient. The process requires energy from respiration
describe mitosis
- the chromosomes in the cell are copied and pulled by spinal fibres to the edge of the cells
- the cell then splits into 2 daughter cells that are used for growth and repair
what is mitosis
one of the processes of cell division, where the cell will be divided into 2 daughter cells
name 4 factors that affect diffusion
- concentration gradient
- temperature
- surface area
- distance particles must travel
what are chromosones
coiled up lengths of DNA molecules, each carrying a large number fo genes
name 4 substances that an diffuse through cell membranes, and 2 that can’t
CAN:
- oxygen
- amino acids
- water
- glucose
CAN’T:
- starch
- protein
what 2 ways are the villi in the small intestine adapted for absorbing digested food
- one cell thick
- very good blood supply to assist quick digestion
2 ways that embryotic stem cells could be used to cure diseases
- they can differentiate into any kind of stem cell
- can divide and produce lots more undifferentiated stem cells
