Bio Grade 10 | Nelson ch. 2

Prokaryote

A cell that does not contain a nucleus or other membrane-bound organelles.

Eukaryote

A cell that contains a nucleus and other organelles, each surrounded by a thin membrane.

Cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended and allows them to move around.

Cell membrane

A thin, flexible barrier that surrounds all cells; regulates what does and does not enter and leaves the cell.

Nucleus

Contains genetic information that controls all cell activities.

Chromosomes

Are found within the nucleus; contains DNA.

Deoxyribonucleic acid (DNA)

The material within chromosomes; contains all of the cell's genetic information. When a cell divides, the DNA is copied so that each new cell has a complete set of chromosomes.

Mitochondria

Sometimes called the "power plants" of the cell because they make energy available to the cell. Active cells, such as muscle cells, have more of these organelles than less active cells, such as fat-storage cells. Cells store energy in the form of glucose. This organelle contains enzymes that help to convert the stored energy into an easily usable form. This process is called cellular respiration and requires oxygen.

Endoplasmic reticulum

A three-dimensional network of branching tubes and pockets. It extends throughout the cytoplasm and is continuous from the nuclear membrane to the cell membrane. These fluid-filled tubes transport materials, such as proteins, through the cell.

Golgi bodies

They collect and process materials to be removed from the cell. They also secrete and make mucus. Cells that secrete a lot of mucus, such as cells lining the intestine, have many of these organelles.

Vacuoles

A single layer of membrane enclosing fluid in a sac. The functions of these organelles vary greatly, according to the type of cell. These functions include containing some substances, removing unwanted substances from the cell, and maintaining internal fluid pressure (turgor) within the cell. Some animal cells can change their shape to wrap around and surround smaller objects to bring them inside the cell. Amoeba do this to obtain food. Some white blood cells engulf bacteria to kill them.

Plant cells

Have a cell wall, large vacuoles, and chloroplasts.

Animal cells

Do not have a cell wall, do not have large vacuoles, and do not have chloroplasts.

Plant cell vacuoles

One large vacuole, which takes up most of the space inside the cell. When these are full of water, turgor pressure keeps the cells plump, which keeps the plant's stems and leaves firm.

Chloroplasts

Found only in plant cells; they contain chlorophyll and give leaves their green colour. They absorb light energy. This light energy is used in photosynthesis. The process that allows plants to make their food.

Cell wall

Found just outside the cell membrane ONLY in plant cells; a rigid porous structure made of cellulose. It provides support for the cell and protection from physical injury.

What are the three reasons for cell division?

Reproduction, growth, and repair.

What are the three stages of the cell cycle?

Interphase, mitosis, and cytokinesis.

Interphase

Cell grows, performs its normal functions, and prepares for division by having copied DNA.

Mitosis

The stage of the cell cycle in which the DNA in the nucleus is divided; the first part of cell division. It is composed of four phases: prophase, metaphase, anaphase, and telophase (PMAT).

Prophase

In a phase of mitosis; the DNA condenses, becoming shorter and thicker and forming chromosomes. Each chromosome is made up of two identical chromatids. The nuclear membrane starts to dissolve, releasing the chromosomes into the cytoplasm.

Metaphase

In a phase of mitosis; the chromosomes line up in the middle of the cell. The nuclear membrane completely dissolves.

Anaphase

In a phase of mitosis; each chromosome separates into two identical single-stranded parts (formerly the chromatids; now the daughter chromosomes). The spindle fibres pull the daughter chromosomes toward each end of the cell.

Telophase

In a phase of mitosis; the chromosomes reach opposite ends of