Download 2nd 6 weeks Review Cells Cell membrane – controls what enters

2nd 6 weeks Review
Cells
Cell membrane – controls what enters and exits the cell
Cell wall – provides strength and shape to plant cells (plant cell only)
Nucleus – were genetic material is stored. Directs the activities of the cell.
Cytoplasm – the flowing, jelly-like material where other cell organelles are located
Mitochondrion – the cell organelle that produces energy used within the cell.
Chloroplast – organelle that contains chlorophyll and where plat cell photosynthesis occurs (plant cells
only)
Vacuole – storage organelle for the cell. Stores items such as water, food, wastes and proteins. Large in plants
and provides a supporting structural role. Small and numerous in animal cells.
Prokaryotic – cells that do not contain a nucleus
Eukaryotic – cells that contain a nucleus and other membrane-bound organelles
Pre-AP Cells
Lysosome – contains enzymes for breaking down waste, old cell parts and invaders in the cell
Golgi Body – packages proteins and lipids to send out of the cell
Endoplasmic Recticulum – transports proteins and lipids with in the cell
Ribosome – Protein factories, combines the amino acids following instructions provided by the nucleus
Cytoskeleton – Protein filaments throughout the cytoplasm which gives the cells shape, helps with
movement, and supports cellular division
Genetic Material
Base pairs – The “steps” in the double helix (twisted ladder)
DNA – The twisted ladder, molecule
Gene – Enough DNA to code for one characteristic or trait
Chromosomes - 1,000s of genes together, passed on to offspring during reproduction, stored in the nucleus
of eukaryotic cells
Heredity - The passing of traits from parent to offspring
Genetics – The study of heredity
Names to Know – Rosalind Franklin, James Watson, Francis Crick, Gregor Mendel
Turgor Pressure
Turgor Pressure: is a force exerted outward on a plant cell wall by the water contained in the cell. This force
gives the plant rigidity, and may help to keep it erect. Turgor can result in the bursting of a cell. Turgor
Pressure: also called turgidity, is the main pressure of the cell contents against the cell wall in plant cells.
Turgid plant cells contain more water than flaccid cells and exert a greater pressure on its cell walls. When
the vacuole is full it cause the plant to be up right, when the vacuole is empty to cause the plant to wilt.
Tropisms
Tropism : a response of a plant to an environmental stimulus.
Phototropism: a tendency of plants to grow toward a source of light.
Thigmotropism : the response of plants to touch.
Gravitropism/geotropism: a tendency of a plant to grow in a direction in response to the force of gravity.
Negatively geotropic: means that the plant fights gravity and grow upward.
Positively geotropic: means that the plants don’t fight against gravity and grow downward.
Photosynthesis
The student is expected to recognize that radiant energy from the Sun is transformed into chemical energy
through the process of photosynthesis.
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Key Concept 1: The Sun emits radiant energy towards Earth’s surface. Some of this radiant energy is
in the form of light.
Key Concept 2: Photosynthesis is a chemical reaction that occurs in plants. During this reaction,
carbon dioxide absorbs from the atmosphere and water absorbs from the soil. The chemical energy
produced from the reaction is in the form of sugar also referred to as glucose. Oxygen also produces
and releases into the atmosphere.
Key Concept 3: The chemical energy or glucose stores in plants, which sustains life on Earth.
Key Concept 4: Plant cells contain chloroplasts for photosynthesis, a large central vacuole (chemical
storage) and a cell wall (protection and structure).
Asexual and Sexual Reproduction
Asexual Reproduction: a type of reproduction in which a new organism is produced from one parent and
has the same DNA or genetic material as the parent Requires only one parent, offspring have 100% the same
chromosomes as the parent.
Advantages: Animals that remain in one particular place and are unable to look for mates would
need to reproduce asexually. Numerous offspring can be produced without "costing" the parent a
great amount of energy or time. This type of reproduction is also faster. Environments that are stable
and experience very little change are the best places for organisms that reproduce asexually.
Disadvantages: Lack of genetic variation - all of the organisms are genetically identical and
therefore share the same weaknesses. If the stable environment changes, the consequences could be
deadly to all of the individuals.
Types of Asexual Reproduction: Binary fission is a form of asexual reproduction where every organelle is
copied and the organism divides in two. Budding is where a new individual develops from an outgrowth
of a parent, splits off, and lives independently. Regeneration occurs when a body part has broken off and
the organism grows a new one.
Sexual reproduction: a type of reproduction in which two cells, usually an egg and a sperm, join to form a
new organism with its own genetic identity Sexual Reproduction results in a variety of off spring.
Advantage: Allows genetic variation within a species which assists with the species survival
Disadvantages: Requires 2 parents, Reproduction is slower