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41 Cards in this Set
- Front
- Back
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Biconcave |
Describes a shape with a dip that curves inwards on both sides |
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Red Blood Cells |
Have a biconcave shape, to allow oxygen to be absorbed more quickly. They also have no nucleus, which means they can absorb more oxygen. |
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What are 6 types of specialised cells? |
Sperm cell Nerve cell Muscle cell Root hair cell Xylem cell Phloem cell |
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What does a sperm cell look like? |
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Adaptations of sperm cells |
Have a tail - helps them swim towards the ovum Lots of mitochondria - energy to keep them swimming |
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What must be done to control our actions? |
Signals must be sent and received |
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Structure of a nerve cell |
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Adaptations of nerve cells |
Myelin Sheath - insulates the electrical impulses Small extensions - pick up signals from neighbouring cells |
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Axon |
The extension of a nerve cell along which electrical impulses travel |
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Myelin Sheath |
The insulating cover along an axon, which speeds up the electrical impulse |
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Three types of muscle cells |
Smooth muscle Cardiac Muscle Skeletal Muscle |
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What can all three types of muscle in our bodies? |
Contract and relax |
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Smooth Muscles |
Contracts and relaxes automatically. |
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Where are smooth muscles found? |
Linings of the vessels that make up our circulatory system Iris of our eyes |
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Cardiac muscles |
Contract and relaxes automatically |
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Where are cardiac muscles found? |
In our heart |
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Skeletal Muscles |
We control the contractions of these muscles so movements are not automatic |
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Where are skeletal muscles found? |
Attached to our bones |
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All three types of muscles are... |
Made from muscle cells. Require lots of mitochondria |
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Structure of a Root Hair Cell |
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Adaptations of Root Hair Cell |
Have a small thin extension which pokes out into the soil Increases surface area --> plants can absorb more water and minerals from the soil. |
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Xylem Cells structure |
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What do xylem cells carry? |
Water and some dissolved minerals from the roots upwards to other parts of the plants. |
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Xylem |
Dead plant cells joined together into long tubes through which water flows during transpiration |
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Transpiration |
The gradual release of water vapour from leaves to continue the pull of water up to them from the soil |
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Where does xylem carry water? |
To the green parts of the plants for photosynthesis during the day. |
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Do xylem cells have end walls? |
No they have no end walls, and no contents (hollow) |
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What reinforces a xylem tubes side walls? |
Lignin |
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Phloem |
Living cells that carry sugars made in photosynthesis to all cells of a plant. |
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Translocation |
The movement of sugars made in photosynthesis from the leaves of plants |
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What do phloem cells carry? |
Glucose (as sucrose) made in photosynthesis |
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What is the sugar used for? |
Immediately in respiration Stored as starch in cells or structures such as the roots of vegetables. |
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Structure of Phloem |
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What are Sieves Plates |
Specialised end walls with small holes in them |
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How are phloem and xylem cells arranged? |
In bundles together which make up the veins you see in a leaf. Xylem towards the leaf. Phloem away |
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Cell differentiation |
Generalised cells become specialised as an organism develops |
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When does cell differentiation occur? |
While you are in your mothers uterus |
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Till when can plant cells differentiate? |
Throughout their life |
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Embryonic Stem Cells |
Inner cell mass of blastocyst Can become any type of cell Some left on umbilical chord |
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Pluripotent |
Embryonic stem cells Can become any cell |
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Meristem/ Plant Stem Cells |
Found in plants Can differentiate at any time |
