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.

·  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