Cell Organization Flashcards
Describe the function of the mitochondria and
suggest a reason why they are arranged around the
filament near the tail of the sperm.
Mitochondria releases energy from glucose and is the site of aerobic respiration.
The mitochondria is at the site of movement of the sperm which allows the sperm to move faster.
Describe the organelles in the cell
Vacuole- contains cell sap; keeps the cell turgid
Cell membrane- controls what enters and leaves the cell
Cell wall- strengthens the cell, made up of cellulose
Mitchondria- releases energy, site of aerobic respiration.
Chloroplast- contains chlorophyll, traps light energy for photosynthesis.
Nucleus- controls activities of the cell
Explain why the root hair cell does
not need chloroplasts.
They don’t need chlorophyll, and their roots don’t need to photosynthesize
State the difference of prokaryotes and eukaryotes-
Prokaryotes-
Very small cells
No mitochondria
There is a cell wall, but it is not made up of cellulose
plasmids present
No nucleus, but there is a single loop of DNA in the cytoplasm
Eukaryotes-
Bigger cells
Nucleus present
Mitochondria present
There is no cell wall in animal cells, but plant cells have a cell wall made up of cellulose
No plasmids present
Suggest why mitochondria are not found in
Bacterial Cells?
The bacterial cell is about the same size as the mitochondria
What are the adaptations of the root hair cell-
Long projection which increases the surface area which speeds up the absorption of water and minerals
Lots of mitochondria to release energy for mineral absorption
Describe all types of tissues-
Epithelial tissues- cells that are closely packed together in the form of a layer, they cover outside the body and internal organs.
Muscular tissue- are specialized cells that are able to contract and bring about a movement.
Glandular tissues- secretory cells that are able to secrete substances such as enzymes and hormones
What is the difference between phloem and xylem
Xylem- transports water and mineral ions from the roots to the leaves.
Phloem- transports dissolved sugars from the leaves to the roots.
Describe how the structure of xylem and phloem relate to its function-
Xylem have thick walls with lignin which helps strengthens/supports the cell to withstand the pressure of the water and minerals flowing.
No end walls so that the water and mineral ions can flow quickly.
Phloem-
Pores in the end wall so that the dissolved sugars can move from cell to cell
Many mitochondria to release energy for sugar transport.
Describe the structure of the leaf and the functions of the
tissues in the leaf.
Upper and lower epidermis secretes a waxy cuticle which reduces water loss
They have a single layer of transparent cells which allow light to pass through
Palisade mesophyll: has many chloroplasts for maximized light absorption for photosynthesis
Spongy mesophyll: has large air spaces which increases the surface area allowing rapid diffusion
Guard cells: reduce water loss. Allow CO2 in and out
What is diffusion?
Spreading of molecules from an area of high concentration to an area of low concentration down the concentration gradient.
Describe 3 factors that increase rate of diffusion
Increasing concentration gradient
Increasing temperature
Increasing surface area
The image below shows part of a plant root.
The plant root is adapted for absorbing water from the
soil. (Many hairs)
Use information from the diagram to explain how this plant
root is adapted for absorbing water. (3 Marks)
There are many hairs which are one cell thick
which provides a short diffusion pathway
Causing there to be more osmosis of water to get into the root.
What is active transport? And how does it get energy?
Active transport is the movement of dissolved molecules into a region of lower concentration to a higher concentration
The particles move against the concentration gradient by using energy released from respiration
What is the function of the stomata?
Controls water loss/evaporation
